U.S. patent application number 11/391242 was filed with the patent office on 2006-08-10 for method for the formation of a metal film.
This patent application is currently assigned to MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Takao Abe, Saneyuki Goya, Toshihiko Nishimori, Hitoshi Sakamoto, Noriaki Ueda.
Application Number | 20060177583 11/391242 |
Document ID | / |
Family ID | 27481142 |
Filed Date | 2006-08-10 |
United States Patent
Application |
20060177583 |
Kind Code |
A1 |
Sakamoto; Hitoshi ; et
al. |
August 10, 2006 |
Method for the formation of a metal film
Abstract
A method for forming a metal film, including bringing a raw
material gas containing a halogen into contact with a hot metallic
filament, thereby etching the filament with the raw material gas to
produce a precursor composed of a metallic component contained in
the filament and the halogen contained in the raw material gas,
producing an atomic reducing gas by heating a reducing gas to a
high temperature, passing the precursor through the atomic reducing
gas to remove the halogen from the precursor, and directing the
resulting metallic ion or neutral metal onto a substrate to form a
thin metal film on the substrate.
Inventors: |
Sakamoto; Hitoshi;
(Takasago-shi, JP) ; Nishimori; Toshihiko;
(Yokohama-shi, JP) ; Goya; Saneyuki;
(Yokohama-shi, JP) ; Abe; Takao; (Yokohama-shi,
JP) ; Ueda; Noriaki; (Kobe-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
MITSUBISHI HEAVY INDUSTRIES,
LTD.
Tokyo
JP
|
Family ID: |
27481142 |
Appl. No.: |
11/391242 |
Filed: |
March 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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|
10684503 |
Oct 15, 2003 |
|
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11391242 |
Mar 29, 2006 |
|
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09926624 |
Nov 27, 2001 |
6656540 |
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PCT/JP01/02392 |
Mar 26, 2001 |
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10684503 |
Oct 15, 2003 |
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Current U.S.
Class: |
427/250 ; 216/37;
427/255.28 |
Current CPC
Class: |
C23C 16/505 20130101;
C23C 16/08 20130101; C23C 16/14 20130101; C23C 16/452 20130101;
H01L 21/28556 20130101; C23C 16/45565 20130101; C23C 16/4488
20130101 |
Class at
Publication: |
427/250 ;
216/037; 427/255.28 |
International
Class: |
C23C 16/00 20060101
C23C016/00; B44C 1/22 20060101 B44C001/22 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2000 |
JP |
2000-320136 |
May 31, 2000 |
JP |
2000-161507 |
Apr 10, 2000 |
JP |
2000-108120 |
Mar 27, 2000 |
JP |
2000-085511 |
Claims
1. A method for forming a metal film, comprising: bringing a raw
material gas containing a halogen into contact with a hot metallic
filament, thereby etching the filament with the raw material gas to
produce a precursor comprising a metallic component contained in
the filament and the halogen contained in the raw material gas;
producing an atomic reducing gas by heating a reducing gas to a
high temperature; passing the precursor through the atomic reducing
gas to remove the halogen from the precursor; and directing the
resulting metallic ion or neutral metal onto a substrate to form a
thin metal film on the substrate.
2. A method for forming a metal film as claimed in claim 1, wherein
the bringing of the raw material gas into contact with the filament
comprises bubbling a carrier gas through a liquid organometallic
complex and vaporizing the organometallic complex.
3. A method for forming a metal film, comprising: bringing a raw
material gas containing a halogen into contact with a hot metallic
filament, thereby etching the filament with the raw material gas to
produce a precursor comprising a metallic component contained in
the filament and the halogen contained in the raw material gas;
passing a high-frequency electric current through an electrode
having openings that allow the precursor to flow therethrough,
thereby converting a reducing gas into a plasma to generate a
reducing gas plasma; passing the precursor through the plasma to
remove the halogen from the precursor; and directing the resulting
metallic ion or neutral metal onto a substrate to form a thin metal
film on the substrate.
4. A method for forming a metal film as claimed in claim 3, wherein
the bringing of the raw material gas into contact with the filament
comprises bubbling a carrier gas through a liquid organometallic
complex and vaporizing the organometallic complex.
5. A method for forming a metal film, comprising: reacting chlorine
with a metallic plate within a chamber to produce a precursor
comprising a metallic component and chlorine; removing chlorine
from the precursor by reduction; and directing the resulting
metallic ion onto a substrate within the chamber to form a metal
film on the substrate, wherein the chamber is heated to a
predetermined temperature so as to prevent the precursor from
depositing on the inner wall of the chamber.
6. A method for forming a metal film as claimed in claim 5, wherein
the metallic plate is made of copper, so that Cu.sub.xCl.sub.y is
produced as the precursor.
7. A method for forming a metallic film as claimed in claim 6,
wherein the predetermined temperature to which the metallic plate
is heated is in the range of 200 to 800.degree. C.
8. A method for forming a metal film, comprising: reacting chlorine
with a metallic plate within a chamber to produce a precursor
comprising a metallic component and chlorine; removing chlorine
from the precursor by reduction; and directing the resulting
metallic ion onto a substrate within the chamber to form a metal
film on the substrate, wherein the metallic plate is heated to a
predetermined temperature so as to make the precursor easy to
reduce.
9. A method for forming a metal film as claimed in claim 8, wherein
the metal plate is made of copper, so that Cu.sub.xCl.sub.y is
produced as the precursor.
10. A method for forming a metal film as claimed in claim 9,
wherein the predetermined temperature to which the metallic plate
is heated is in the range of 200 to 800.degree. C.
11. A method for forming a metal film, comprising: reacting
chlorine with a metallic plate within a chamber to produce a
precursor comprising a metallic component and chlorine; removing
chlorine from the precursor by reduction; and directing the
resulting metallic ion onto a substrate within the chamber to form
a metal film on the substrate, wherein the chamber is heated to a
predetermined temperature so as to prevent the precursor from
depositing on the inner wall of the chamber and the metallic plate
is heated to a predetermined temperature so as to make the
precursor easy to reduce.
12. A method for forming a metal film as claimed in claim 11,
wherein the metallic plate is made of copper, so that
Cu.sub.xCl.sub.y is produced as the precursor.
13. A method for forming a metallic film as claimed in claim 12,
wherein the predetermined temperature to which the metallic plate
is heated is in the range of 200 to 800.degree. C.
Description
TECHNICAL FIELD
[0001] This invention relates to methods and apparatus for the
formation of a thin noble metal film by a plasma-excited vapor
phase growth process.
[0002] Moreover, this invention also relates to apparatus and
methods for forming a metal film on a substrate surface by a vapor
phase growth process.
[0003] Furthermore, this invention also relates to apparatus for
the vapor phase growth of a thin copper film which are useful, for
example, in the formation of wiring material films for use in
semiconductor devices.
BACKGROUND ART
[0004] Conventionally, where it is desired to form a thin noble
metal film by a vapor phase growth process, such a film has been
formed by the utilization of a thermal reaction using a liquid
organometallic complex, such as copper
hexafluoroacetylacetonato-trimethylvinylsilane [hereinafter
referred to as Cu(hfac)(tmvs)], as a raw material.
[0005] FIG. 22 is a schematic view of a conventional apparatus 500
for the vapor phase growth of a thin noble metal film. The method
for forming a thin noble metal film 541 on a substrate 515 by using
this apparatus 500 is described below. First of all, a liquid raw
material 522 comprising Cu(hfac)(tvs) is contained in a raw
material vessel 521, and a carrier gas comprising He gas is bubbled
therethrough. The raw material evaporated by bubbling and H.sub.2
for reduction reaction are passed through flow controllers 503,506
to control their flow rates, respectively, and fed into an inlet
vessel 511 having a vaporizer 520 for vaporizing the raw material
completely. Thereafter, the resulting precursor 513 is introduced
into a reaction vessel 501 through a perforated plate 512. A
substrate 515 is disposed beneath perforated plate 512 and placed
on a heater 516. In this method, the growth rate and the film
quality have been improved by controlling the flow rates of raw
material 522 and H.sub.2 for reduction reaction and the growth
temperature.
[0006] However, the above-described prior art involves the
following three problems.
[0007] First, since this method is based on the utilization of a
thermal reaction induced on the substrate surface by heating
substrate 515, it has been difficult to improve the rate of film
growth.
[0008] Secondly, the organometallic complex [e.g., Cu(hfac)(tmvs)]
used as the raw material is expensive.
[0009] Thirdly, since hexafluoroacetylacetonato (hfac) and
trimethylvinylsilane (tmvs) attached to Cu in Cu(hfac)(tmvs) remain
in the thin Cu film (constituting thin film 541) as impurities, it
has been difficult to improve the film quality.
[0010] Moreover, where it is desired to form a metal film (e.g., a
thin copper film) by a vapor phase growth process, it has been
conventional practice to use a liquid organometallic complex (e.g.,
copper hexafluoroacetylacetonato-trimethylvinylsilane) as a raw
material, dissolve the solid raw material in a solvent, vaporize
it, and form a film on a substrate by the utilization of a thermal
reaction.
[0011] However, since the prior art involves the formation of a
film by the utilization of a thermal reaction, it has been
difficult to improve the rate of film growth. Moreover, the metal
complex used as the raw material is expensive. Furthermore, since
hexafluoroacetylacetonato and trimethylvinylsilane attached to Cu
remain in the thin Cu film as impurities, it has been difficult to
improve the film quality.
[0012] Furthermore, a thin copper (Cu) film has conventionally been
formed by physical film-forming processes such as vacuum
evaporation, ion plating and sputtering, and a chemical vapor phase
growth process (CVD process). Among others, the CVD process is
widely employed because of its excellent surface covering
properties.
[0013] According to a conventionally known method for the formation
of a thin copper film by the CVD process, a liquid organocopper
complex such as copper
hexafluoroacetylacetonato-trimethylvinylsilane [hereinafter
referred to as Cu(hfac)(tmvs)] is used as a raw material. This raw
material is evaporated, carried to a desired surface of a substrate
to be treated, and thermally decomposed to form a thin copper film
on the substrate surface.
[0014] The above-described method for the formation of a thin
copper metal is more specifically described with reference to FIG.
23 illustrating an apparatus 600 for the vapor phase growth of a
thin copper film. First of all, a substrate 603 to be treated is
placed on a flat plate type heater 602 within a reaction vessel
601. The gas within the aforesaid reaction vessel 601 is discharged
through an .exhaust pipe 604 until a predetermined degree of vacuum
is reached. Subsequently, a carrier gas such as He is fed through a
pipe 607a and bubbled through a raw material 605 [i.e.,
Cu(hfac)(tmvs)] contained in a raw material vessel 606. The raw
material gas obtained by bubbling and a reducing gas (e.g.,
hydrogen) are conducted through pipes 607b and 607c, respectively,
and fed into a vaporizer 608 disposed in the upper part of the
aforesaid reaction vessel 601. The flow rates of the aforesaid raw
material gas and hydrogen gas are controlled by flow controllers
609 and 610 installed in the respective pipes 607b and 607c. After
the raw material gas is completely vaporized in the aforesaid
vaporizer 608, a mixed gas 613 composed of the raw material gas and
hydrogen gas is discharged through a plurality of discharge
orifices 612 of a discharge plate 611 disposed at the bottom of
vaporizer 608 so as to travel toward the aforesaid substrate 603
placed on the aforesaid heater 602. Since the aforesaid substrate
603 is heated to a predetermined temperature by the aforesaid flat
plate type heater 602, the aforesaid raw material, or
Cu(hfac)(tmvs), is thermally decomposed on the surface of substrate
603 to form a thin copper film 614 thereon. During this film
formation, the oxidation of copper is prevented by the reducing
action of hydrogen. By controlling the flow rates of the aforesaid
raw material and hydrogen and the heating temperature by heater
602, the rate of copper film growth can be regulated and the film
quality can be improved.
[0015] However, the above-described conventional method for the
formation of a thin copper film involves the following three
problems.
[0016] First, since the above-described method for the formation of
a thin copper film is based on the thermal decomposition of
vaporized Cu(hfac)(tmvs), it is difficult to improve the rate of
film growth. Secondly, the organocopper complex [e.g., Cu(hfac)
(tmvs)] used as the raw material is expensive and hence raises the
cost of the resulting thin copper film. Thirdly, since
hexafluoroacetylacetonato (hfac) and trimethylvinylsilane (tmvs)
are incorporated into the thin copper film during its formation and
remain therein as impurities, the film quality tends to be
reduced.
[0017] The present invention has been made in view of the
above-described circumstances, and an object thereof is to provide
methods and apparatus for the formation of a thin noble metal film
which can achieve a high rate of film growth, can use inexpensive
raw materials, and do not allow any impurities to remain in the
thin film.
[0018] Another object of the present invention is to provide
methods and apparatus for the formation of a metal film which can
achieve a high rate of film growth, can use inexpensive raw
materials, and do not allow any impurities to remain in the
film.
[0019] Still another object of the present invention is to provide
an apparatus for the vapor phase growth of a thin copper film which
uses inexpensive chlorine or hydrogen chloride as a raw material
gas, can achieve a high rate of film growth, and can form a thin
copper film of good quality containing little residual impurity and
having a desired film thickness.
DISCLOSURE OF THE INVENTION
[0020] In order to accomplish the above objects, the present
invention provides a method for the formation of a metal film which
comprises the steps of feeding a raw material gas containing a
halogen into an inlet vessel having a perforated plate made of
metal; converting the raw material gas into a plasma to generate a
raw material gas plasma; etching the perforated plate with the raw
material gas plasma to produce a precursor composed of the metallic
component contained in the perforated plate and the halogen
contained in the raw material gas; converting a reducing gas into a
plasma to generate a reducing gas plasma; after discharging the
precursor from the inlet vessel, passing the precursor through a
rotating magnetic field so as to cause the precursor to travel
toward a substrate in an accelerated manner; and passing the
precursor through the reducing gas plasma to remove the halogen
from the precursor and directing the resulting metallic ion or
neutral metal onto the substrate to form a thin metal film on the
substrate.
[0021] The aforesaid metallic ion is a metal atom which has been
ionized by the release of an electron or electrons, and the
aforesaid neutral metal is a metal atom which has not been
ionized.
[0022] The aforesaid perforated plate is preferably made of Cu or a
noble metal such as Ag, Au or Pt. For example, when a perforated
plate made of Cu is used, Cu.sub.xCl.sub.y is produced as the
aforesaid precursor. Consequently, Cu ions are directed onto the
substrate to form a thin Cu film.
[0023] Since two plasmas (i.e., the raw material gas plasma and the
reducing gas plasma) are used in this method, the reaction
efficiency is markedly improved to cause an increase in rate of
film growth. Moreover, since a chlorine-containing gas is used as
the raw material gas and a hydrogen-containing gas is used as the
reducing gas, a marked reduction in cost is achieved. Furthermore,
since the reduction reaction can be accelerated independently, the
amount of impurities (e.g., chlorine) remaining in the thin film
can be minimized to form a thin film of high quality.
[0024] According to another embodiment of the present invention,
the above objects are accomplished by providing a method for the
formation of a metal film which comprises the steps of feeding a
raw material gas containing a halogen into an inlet vessel having a
perforated plate made of metal; converting the raw material gas
into a plasma to generate a raw material gas plasma; etching the
perforated plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
perforated plate and the halogen contained in the raw material gas;
converting a reducing gas into a plasma to generate a reducing gas
plasma; and passing the precursor through the reducing gas plasma
to remove the halogen from the precursor and directing the
resulting metallic ion or neutral metal onto the substrate to form
a thin metal film on the substrate.
[0025] The aforesaid perforated plate is preferably made of Cu or a
noble metal such as Ag, Au or Pt. For example, when a perforated
plate made of Cu is used, Cu.sub.xCl.sub.y is produced as the
aforesaid precursor. Consequently, Cu ions are directed onto the
substrate to form a thin Cu film.
[0026] In order to generate the aforesaid reducing gas plasma,
there may be used an electrode to which high-frequency electric
power is applied. For example, the precursor diffusing toward the
aforesaid substrate may be reduced by disposing an electrode
opposite to the substrate and generating a plasma all over the
electrode.
[0027] Since two plasmas (i.e., the raw material gas plasma and the
reducing gas plasma) are used in this method, the reaction
efficiency is markedly improved to cause an increase in rate of
film growth. Moreover, since a halogen-containing gas is used as
the raw material gas and a hydrogen-containing gas is used as the
reducing gas, a marked reduction in cost is achieved. Furthermore,
since the reduction reaction can be accelerated independently, the
amount of impurities (e.g., chlorine) remaining in the thin film
can be minimized to form a thin film of high quality.
[0028] According to still another embodiment of the present
invention, there is provided a method for the formation of a metal
film which comprises the steps of feeding a raw material gas
containing a halogen into an inlet vessel having a perforated plate
made of metal; converting the raw material gas into a plasma to
generate a raw material gas plasma; etching the perforated plate
with the raw material gas plasma to produce a precursor composed of
the metallic component contained in the perforated plate and the
halogen contained in the raw material gas; producing an atomic
reducing gas between the perforated plate and a substrate by
heating a reducing gas to a high temperature; and, after
discharging the precursor from the inlet vessel, passing the
precursor through the atomic reducing gas to remove the halogen
from the precursor and directing the resulting metallic ion or
neutral metal onto the substrate to form a thin metal film on the
substrate.
[0029] According to this method, the reaction efficiency is
markedly improved to cause an increase in rate of film growth.
Moreover, since a halogen-containing gas is used as the raw
material gas and a hydrogen-containing gas is used as the reducing
gas, a marked reduction in cost is achieved. Furthermore, since the
reduction reaction can be accelerated independently, the amount of
impurities (e.g., chlorine) remaining in the thin film can be
minimized to form a thin film of high quality.
[0030] According to a further embodiment of the present invention,
there is provided a method for the formation of a metal film which
comprises the steps of bringing a raw material gas containing a
halogen into contact with a hot metallic filament and thereby
etching the filament with the raw material gas to produce a
precursor composed of the metallic component contained in the
filament and the halogen contained in the raw material gas;
producing an atomic reducing gas by heating a reducing gas to a
high temperature; and passing the precursor through the atomic
reducing gas to remove the halogen from the precursor and directing
the resulting metallic ion or neutral metal onto a substrate to
form a thin metal film on the substrate.
[0031] According to the above-described method, the reaction
efficiency is markedly improved to cause an increase in rate of
film growth. Moreover, since a halogen-containing gas is used as
the raw material gas and a hydrogen-containing gas is used as the
reducing gas, a marked reduction in cost is achieved. Furthermore,
since the reduction reaction can be accelerated independently, the
amount of impurities (e.g., chlorine) remaining in the thin film
can be minimized to form a thin film of high quality.
[0032] According to still a further embodiment of the present
invention, there is provided a method for the formation of a metal
film which comprises the steps of bringing a raw material gas
containing a halogen into contact with a hot metallic filament and
thereby etching the filament with the raw material gas to produce a
precursor composed of the metallic component contained in the
filament and the halogen contained in the raw material gas;
utilizing high-frequency electric power for the purpose of
converting a reducing gas into a plasma to generate a reducing gas
plasma; and passing the precursor through the reducing gas plasma
to remove the halogen from the precursor and directing the
resulting metallic ion or neutral metal onto a substrate to form a
thin metal film on the substrate.
[0033] According to the above-described method, the reaction
efficiency is markedly improved to cause an increase in rate of
film growth. Moreover, since a halogen-containing gas is used as
the raw material gas and a hydrogen-containing gas is used as the
reducing gas, a marked reduction in cost is achieved. Furthermore,
since the reduction reaction can be accelerated independently, the
amount of impurities (e.g., chlorine) remaining in the thin film
can be minimized to form a thin film of high quality.
[0034] In the methods for forming a metal film in accordance with
the present invention, a halogen gas, a hydrogen halide gas, or a
mixed gas composed of these gases is used as the aforesaid raw
material gas. For example, there may be used fluorine gas, chlorine
gas, bromine gas, iodine gas, and hydrogen halide gases formed by
the combination of these halogens with hydrogen. Among these gases,
hydrogen chloride gas has higher reaction efficiency than chlorine
gas. Consequently, the use of hydrogen chloride gas can decrease
the amount of reducing gas used and hence cause a reduction in
cost.
[0035] Moreover, the above-described steps extending from the
feeding of a raw material gas to the production of a precursor may
be replace by a method comprising the step of bubbling a carrier
gas (e.g., He) through a liquid organometallic complex to evaporate
it, and the step of vaporizing the evaporated organometallic
complex in a vaporizer or the like and introducing the resulting
vapor into the reaction vessel.
[0036] According to these methods, the reducing gas plasma
decomposes the impurities (e.g., halogen compounds and carbon
compounds) contained in the raw material gas, the amount of
impurities remaining in the thin metal film can be reduced.
[0037] According to the present invention, there is also provided
an apparatus for the formation of a metal film which comprises an
inlet vessel equipped with a metallic perforated plate having
discharge orifices bored therethrough and adapted to receive a raw
material gas in its internal volume; a first plasma generator for
converting the raw material gas received in the inlet vessel into a
plasma and thereby generating a raw material gas plasma; a reaction
vessel housing the inlet vessel and a substrate; a-rotating
magnetic field generator for creating a rotating magnetic field
between the perforated plate and the substrate; and a second plasma
generator for generating a plasma from a reducing gas fed into the
reaction vessel.
[0038] As the aforesaid rotating magnetic field generator, there
may be used, for example, a device comprising a rotating magnetic
field coil disposed on the side of the reaction vessel, and a power
supply for passing a high electric current through the rotating
magnetic field coil.
[0039] According to another embodiment of the present invention,
there is provided an apparatus for the formation of a metal film
which comprises an inlet vessel equipped with a metallic perforated
plate having discharge orifices bored therethrough and adapted to
receive a raw material gas in its internal volume; a first plasma
generator for converting the raw material gas received in the inlet
vessel into a plasma and thereby generating a raw material gas
plasma; a reaction vessel housing the inlet vessel and a substrate;
and a meshlike, ladderlike or comblike electrode for generating a
plasma from a reducing gas fed into the reaction vessel by applying
high-frequency electric power thereto.
[0040] By providing the electrode surface with holes or openings,
the flux of the precursor can be subjected to a reduction reaction
uniformly, without preventing the precursor from traveling toward
the substrate.
[0041] According to still another embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film which comprises an inlet vessel equipped with a metallic
perforated plate having discharge orifices bored therethrough and
adapted to receive a raw material gas in its internal volume; a
plasma generator for converting the raw material gas received in
the inlet vessel into a plasma and thereby generating a raw
material gas plasma; a reaction vessel housing the inlet vessel and
a substrate; and a reducing gas heating device for heating a
reducing gas fed into the reaction vessel.
[0042] As the aforesaid reducing gas heating device, there may
preferably be used, for example, a tungsten filament heated to a
high temperature by passing a high electric current therethrough.
When a reducing gas is made to flow through the filament, an atomic
reducing gas is produced.
[0043] According to a further embodiment of the present invention,
there is provided an apparatus for the formation of a metal film
which comprises a precursor feeding device for bringing a raw
material gas into contact with a hot metallic filament to produce a
precursor and feeding the precursor into a reaction vessel; the
reaction vessel housing a substrate; and a reducing gas heating
device for heating a reducing gas fed into the reaction vessel.
[0044] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film which comprises a precursor feeding device for bubbling
a carrier gas through a liquid organometallic complex, vaporizing
the organometallic complex, producing a precursor from the
vaporized organometallic complex, and feeding the precursor into a
reaction vessel; the reaction vessel housing a substrate; a
rotating magnetic field generator for creating a rotating magnetic
field in a space above the substrate; and a second plasma generator
for generating a plasma from a reducing gas fed into the reaction
vessel.
[0045] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film which comprises a precursor feeding device for bubbling
a carrier gas through a liquid organometallic complex, vaporizing
the organometallic complex, producing a precursor from the
vaporized organometallic complex, and feeding the precursor into a
reaction vessel; the reaction vessel housing a substrate; and a
meshlike, ladderlike or comblike electrode for generating a plasma
from a reducing gas fed into the reaction vessel by applying
high-frequency electric power thereto.
[0046] By employing these methods and apparatus for the formation
of a metal film in accordance with the present invention, a thin
metal film of high quality showing no precipitation of impurities
can be rapidly formed at low cost.
[0047] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; a chamber housing the inlet vessel and a
substrate; first plasma generating means for converting the raw
material gas within the inlet vessel into a plasma to generate a
raw material gas plasma, and thereby etching the discharge plate
with the raw material gas plasma to produce a precursor composed of
the metallic component contained in the discharge plate and the
chlorine contained in the raw material gas; second plasma
generating means for converting a hydrogen-containing reducing gas
within the chamber into a plasma to generate a reducing gas plasma;
and chamber heating means for heating the chamber to a
predetermined temperature; whereby the precursor is passed through
the reducing gas plasma within the chamber to remove chlorine from
the precursor by reduction, without allowing the precursor to
deposit on the heated inner wall of the chamber, and the resulting
metallic ion is directed onto the substrate to form a metal film on
the substrate.
[0048] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; discharge plate heating means for heating the
discharge plate to a predetermined temperature; a chamber housing
the inlet vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
and second plasma generating means for converting a
hydrogen-containing reducing gas within the chamber into a plasma
to generate a reducing gas plasma; whereby the precursor, which has
been produced by etching the heated discharge plate and is hence
easy to reduce, is passed through the reducing gas plasma to remove
chlorine from the precursor by reduction, and the resulting
metallic ion is directed onto the substrate to form a metal film on
the substrate.
[0049] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; discharge plate heating means for heating the
discharge plate to a predetermined temperature; a chamber housing
the inlet vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
second plasma generating means for converting a hydrogen-containing
reducing gas within the chamber into a plasma to generate a
reducing gas plasma; and chamber heating means for heating the
chamber to a predetermined temperature; whereby the precursor,
which has been produced by etching the heated discharge plate and
is hence easy to reduce, is passed through the reducing gas plasma
to remove chlorine from the precursor by reduction, without
allowing the precursor to deposit on the heated inner wall of the
chamber, and the resulting metallic ion is directed onto the
substrate to form a metal film on the substrate.
[0050] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; a chamber housing the inlet vessel and a
substrate; first plasma generating means for converting the raw
material gas within the inlet vessel into a plasma to generate a
raw material gas plasma, and thereby etching the discharge plate
with the raw material gas plasma to produce a precursor composed of
the metallic component contained in the discharge plate and the
chlorine contained in the raw material gas; reducing gas heating
means for heating a hydrogen-containing reducing gas to a high
temperature and thereby producing an atomic reducing gas within the
chamber between the substrate and the discharge plate; and chamber
heating means for heating the chamber to a predetermined
temperature; whereby the precursor is passed through the atomic
reducing gas within the chamber to remove chlorine from the
precursor by reduction, without allowing the precursor to deposit
on the heated inner wall of the chamber, and the resulting metallic
ion is directed onto the substrate to form a metal film on the
substrate.
[0051] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; discharge plate heating means for heating the
discharge plate to a predetermined temperature; a chamber housing
the inlet vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
and reducing gas heating means for heating a hydrogen-containing
reducing gas to a high temperature and thereby producing an atomic
reducing gas within the chamber between the substrate and the
discharge plate; whereby the precursor, which has been produced by
etching the heated discharge plate and is hence easy to reduce, is
passed through the atomic reducing gas to remove chlorine from the
precursor by reduction, and the resulting metallic ion is directed
onto the substrate to form a metal film on the substrate.
[0052] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising an inlet vessel equipped with a metallic discharge plate
having a multitude of discharge orifices bored therethrough and
adapted to receive a chlorine-containing raw material gas in its
internal volume; discharge plate heating means for heating the
discharge plate to a predetermined temperature; a chamber housing
the inlet vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
reducing gas heating means for heating a hydrogen-containing
reducing gas to a high temperature and thereby producing an atomic
reducing gas within the chamber between the substrate and the
discharge plate; and chamber heating means for heating the chamber
to a predetermined temperature; whereby the precursor, which has
been produced by etching the heated discharge plate and is hence
easy to reduce, is passed through the atomic reducing gas within
the chamber to remove chlorine from the precursor by reduction,
without allowing the precursor to deposit on the heated inner wall
of the chamber, and the resulting metallic ion is directed onto the
substrate to form a metal film on the substrate.
[0053] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising precursor feeding means for bringing a
chlorine-containing raw material gas into contact with a hot
metallic filament to produce a precursor within a chamber housing a
substrate, the precursor being composed of the metallic component
contained in the metallic filament and the chlorine contained in
the raw material gas; reducing gas heating means for heating a
hydrogen-containing reducing gas to a high temperature and thereby
producing an atomic reducing gas within the chamber between the
substrate and the discharge plate; and chamber heating means for
heating the chamber to a predetermined temperature; whereby the
precursor is passed through the atomic reducing gas within the
chamber to remove chlorine from the precursor by reduction, without
allowing the precursor to deposit on the heated inner wall of the
chamber, and the resulting metallic ion is directed onto the
substrate to form a metal film on the substrate.
[0054] In these apparatus, the discharge plate or metallic filament
may be made of copper, so that Cu.sub.xCl.sub.y is produced as the
aforesaid precursor. Moreover, the discharge plate may be made of
copper and the predetermined temperature to which the discharge
plate is heated by the discharge plate heating means may be in the
range of 200 to 800.degree. C. Furthermore, the discharge plate
heating means may comprise means for heating the discharge plate by
introducing a rare gas into the inlet vessel, using the first
plasma generating means to generate a rare gas plasma, and applying
a voltage so as to cause the rare gas component ion to collide with
the discharge plate.
[0055] In this case, the predetermined temperature is preferably
600.degree. C. When Cu.sub.xCl.sub.y is produced as the aforesaid
precursor, the predetermined temperature to which the chamber is
heated by the chamber heating means is preferably about 200.degree.
C. In addition to Cu, Ag, Au, Pt, Ti, W and the like may be used
for the discharge plate or metallic filament. As the raw material
gas, there may be used chlorine gas, hydrogen chloride gas or a
mixed gas composed of these gases.
[0056] In order to accomplish the above objects, the present
invention also provides a method for the formation of a metal film
which comprises reacting chlorine with a metallic plate within a
chamber to produce a precursor composed of a metallic component and
chlorine, removing chlorine from the precursor by reduction, and
directing the resulting metallic ion onto a substrate within the
chamber to form a metal film on the substrate, the method being
characterized in that the chamber is heated to a predetermined
temperature so as to prevent the precursor from depositing on the
inner wall of the chamber.
[0057] In order to accomplish the above objects, the present
invention also provides a method for the formation of a metal film
which comprises reacting chlorine with a metallic plate within a
chamber to produce a precursor composed of a metallic component and
chlorine, removing chlorine from the precursor. by reduction, and
directing the resulting metallic ion onto a substrate within the
chamber to form a metal film on the substrate, the method being
characterized in that the metallic plate is heated to a
predetermined temperature so as to make the precursor easy to
reduce.
[0058] According to another embodiment of the present invention,
the above objects are accomplished by providing a method for the
formation of a metal film which comprises reacting chlorine with a
metallic plate within a chamber to produce a precursor composed of
a metallic component and chlorine, removing chlorine from the
precursor by reduction, and directing the resulting metallic ion
onto a substrate within the chamber to form a metal film on the
substrate, the method being characterized in that the chamber is
heated to a predetermined temperature so as to prevent the
precursor from depositing on the inner wall of the chamber and,
moreover, the metallic plate is heated to a predetermined
temperature so as to make the precursor easy to reduce.
[0059] In these methods, the metallic plate may be made of copper,
so that Cu.sub.xCl.sub.y is produced as the aforesaid
precursor.
[0060] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; a chamber housing the inlet
vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
second plasma generating means for converting a hydrogen-containing
reducing gas within the chamber into a plasma to generate a
reducing gas plasma; and chamber heating means for heating the
chamber to a predetermined temperature; whereby the precursor is
passed through the reducing gas plasma within the chamber to remove
chlorine from the precursor by reduction, without allowing the
precursor to deposit on the heated inner wall of the chamber, and
the resulting metallic ion is directed onto the substrate to form a
metal film on the substrate. Thus, the precursor is prevented from
depositing on the inner wall of the chamber. Consequently, a high
rate of film growth can be achieved, an inexpensive raw material
can be used, and an apparatus for the formation of a metal film
containing no residual impurities can be obtained. Moreover, the
necessity of cleaning the inside of the chamber periodically can be
eliminated to cause an improvement in raw material efficiency and a
reduction in running cost.
[0061] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; discharge plate heating means
for heating the discharge plate to a predetermined temperature; a
chamber housing the inlet vessel and a substrate; first plasma
generating means for converting the raw material gas within the
inlet vessel into a plasma to generate a raw material gas plasma,
and thereby etching the discharge plate with the raw material gas
plasma to produce a precursor composed of the metallic component
contained in the discharge plate and the chlorine contained in the
raw material gas; and second plasma generating means for converting
a hydrogen-containing reducing gas within the chamber into a plasma
to generate a reducing gas plasma; whereby the precursor, which has
been produced by etching the heated discharge plate and is hence
easy to reduce, is passed through the reducing gas plasma to remove
chlorine from the precursor by reduction, and the resulting
metallic ion is directed onto the substrate to form a metal film on
the substrate. Thus, a monomeric precursor which can be easily
reduced tends to be produced. Consequently, a high rate of film
growth can be achieved, an inexpensive raw material can be used,
and an apparatus for the formation of a metal film containing no
residual impurities can be obtained. Moreover, chlorine can be
removed by reduction in a short period of time, resulting in a
further improvement in the rate of film growth.
[0062] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; discharge plate heating means
for heating the discharge plate to a predetermined temperature; a
chamber housing the inlet vessel and a substrate; first plasma
generating means for converting the raw material gas within the
inlet vessel into a plasma to generate a raw material gas plasma,
and thereby etching the discharge plate with the raw material gas
plasma to produce a precursor composed of the metallic component
contained in the discharge plate and the chlorine contained in the
raw material gas; second plasma generating means for converting a
hydrogen-containing reducing gas within the chamber into a plasma
to generate a reducing gas plasma; and chamber heating means for
heating the chamber to a predetermined temperature; whereby the
precursor, which has been produced by etching the heated discharge
plate and is hence easy to reduce, is passed through the reducing
gas plasma to remove chlorine from the precursor by reduction,
without allowing the precursor to deposit on the heated inner wall
of the chamber, and the resulting metallic ion is directed onto the
substrate to form a metal film on the substrate. Thus, the
precursor is pre vented from depositing on the inner wall of the
chamber and, moreover, a monomeric precursor which can be easily
reduced tends to be produced. Consequently, a high rate of film
growth can be achieved, an inexpensive raw material can be used,
and an apparatus for the formation of a metal film containing no
residual impurities can be obtained. Moreover, the necessity of
cleaning the inside of the chamber periodically can be eliminated
to cause an improvement in raw material efficiency and a reduction
in running cost. Furthermore, chlorine can be removed by reduction
in a short period of time, resulting in a further improvement in
the rate of film growth.
[0063] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; a chamber housing the inlet
vessel and a substrate; first plasma generating means for
converting the raw material gas within the inlet vessel into a
plasma to generate a raw material gas plasma, and thereby etching
the discharge plate with the raw material gas plasma to produce a
precursor composed of the metallic component contained in the
discharge plate and the chlorine contained in the raw material gas;
reducing gas heating means for heating a hydrogen-containing
reducing gas to a high temperature and thereby producing an atomic
reducing gas within the chamber between the substrate and the
discharge plate; and chamber heating means for heating the chamber
to a predetermined temperature; whereby the precursor is passed
through the atomic reducing gas within the chamber to remove
chlorine from the precursor by reduction, without allowing the
precursor to deposit on the heated inner wall of the chamber, and
the resulting metallic ion is directed onto the substrate to form a
metal film on the substrate. Thus, the precursor is prevented from
depositing on the inner wall of the chamber. Consequently, a high
rate of film growth can be achieved, an inexpensive raw material
can be used, and an apparatus for the formation of a metal film
containing no residual impurities can be obtained. Moreover, the
necessity of cleaning the inside of the chamber periodically can be
eliminated to cause an improvement in raw material efficiency and a
reduction in running cost.
[0064] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; discharge plate heating means
for heating the discharge plate to a predetermined temperature; a
chamber housing the inlet vessel and a substrate; first plasma
generating means for converting the raw material gas within the
inlet vessel into a plasma to generate a raw material gas plasma,
and thereby etching the discharge plate with the raw material gas
plasma to produce a precursor composed of the metallic component
contained in the discharge plate and the chlorine contained in the
raw material gas; and reducing gas heating means for heating a
hydrogen-containing reducing gas to a high temperature and thereby
producing an atomic reducing gas within the chamber between the
substrate and the discharge plate; whereby the precursor, which has
been produced by etching the heated discharge plate and is hence
easy to reduce, is passed through the atomic reducing gas to remove
chlorine from the precursor by reduction, and the resulting
metallic ion is directed onto the substrate to form a metal film on
the substrate. Thus, a monomeric precursor which can be easily
reduced tends to be produced. Consequently, a high rate of film
growth can be achieved, an inexpensive raw material can be used,
and an apparatus for the formation of a metal film containing no
residual impurities can be obtained. Moreover, chlorine can be
removed by reduction in a short period of time, resulting in a
further improvement in the rate of film growth.
[0065] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising an inlet vessel equipped with
a metallic discharge plate having a multitude of discharge orifices
bored therethrough and adapted to receive a chlorine-containing raw
material gas in its internal volume; discharge plate heating means
for heating the discharge plate to a predetermined temperature; a
chamber housing the inlet vessel and a substrate; first plasma
generating means for converting the raw material gas within the
inlet vessel into a plasma to generate a raw material gas plasma,
and thereby etching the discharge plate with the raw material gas
plasma to produce a precursor composed of the metallic component
contained in the discharge plate and the chlorine contained in the
raw material gas; reducing gas heating means for heating a
hydrogen-containing reducing gas to a high temperature and thereby
producing an atomic reducing gas within the chamber between the
substrate and the discharge plate; and chamber heating means for
heating the chamber to a predetermined temperature; whereby the
precursor, which has been produced by etching the heated discharge
plate and is hence easy to reduce, is passed through the atomic
reducing gas within the chamber to remove chlorine from the
precursor by reduction, without allowing the precursor to deposit
on the heated inner wall of the chamber, and the resulting metallic
ion is directed onto the substrate to form a metal film on the
substrate. Thus, the precursor is prevented from depositing on the
inner wall of the chamber and, moreover, a monomeric precursor
which can be easily reduced tends to be produced. Consequently, a
high rate of film growth can be achieved, an inexpensive raw
material can be used, and an apparatus for the formation of a metal
film containing no residual impurities can be obtained. Moreover,
the necessity of cleaning the inside of the chamber periodically
can be eliminated to cause an improvement in raw material
efficiency and a reduction in running cost. Furthermore, chlorine
can be removed by reduction in a short period of time, resulting in
a further improvement in the rate of film growth.
[0066] According to still a further embodiment of the present
invention, the above objects are accomplished by providing an
apparatus for the formation of a metal film, the apparatus
comprising precursor feeding means for bringing a
chlorine-containing raw material gas into contact with a hot
metallic filament to produce a precursor within a chamber housing a
substrate, the precursor being composed of the metallic component
contained in the metallic filament and the chlorine contained in
the raw material gas; reducing gas heating means for heating a
hydrogen-containing reducing gas to a high temperature and thereby
producing an atomic reducing gas within the chamber between the
substrate and the discharge plate; and chamber heating means for
heating the chamber to a predetermined temperature; whereby the
precursor is passed through the atomic reducing gas within the
chamber to remove chlorine from the precursor by reduction, without
allowing the precursor to deposit on the heated inner wall of the
chamber, and the resulting metallic ion is directed onto the
substrate to form a metal film on the substrate. Thus, the
precursor is prevented from depositing on the inner wall of the
chamber. Consequently, a high rate of film growth can be achieved,
an inexpensive raw material can be used, and an apparatus for the
formation of a metal film containing no residual impurities can be
obtained. Moreover, the necessity of cleaning the inside of the
chamber periodically can be eliminated to cause an improvement in
raw material efficiency and a reduction in running cost.
[0067] According to still a further embodiment of the present
invention, there is provided a method for the formation of a metal
film which comprises reacting chlorine with a metallic plate within
a chamber to produce a precursor composed of a metallic component
and chlorine, removing chlorine from the precursor by reduction,
and directing the resulting metallic ion onto a substrate within
the chamber to form a metal film on the substrate, the method being
characterized in that the chamber is heated to a predetermined
temperature so as to prevent the precursor from depositing on the
inner wall of the chamber. Thus, the precursor is prevented from
depositing on the inner wall of the chamber. Consequently, a high
rate of film growth can be achieved, an inexpensive raw material
can be used, and an apparatus for the formation of a metal film
containing no residual impurities can be obtained. Moreover, the
necessity of cleaning the inside of the chamber periodically can be
eliminated to cause an improvement in raw material efficiency and a
reduction in running cost.
[0068] According to still a further embodiment of the present
invention, there is provided a method for the formation of a metal
film which comprises reacting chlorine with a metallic plate within
a chamber to produce a precursor composed of a metallic component
and chlorine, removing chlorine from the precursor by reduction,
and directing the resulting metallic ion onto a substrate within
the chamber to form a metal film on the substrate, the method being
characterized in that the metallic plate is heated to a
predetermined temperature so as to make the precursor easy to
reduce. Thus, a monomeric precursor which can be easily reduced
tends to be produced. Consequently, a high rate of film growth can
be achieved, an inexpensive raw material can be used, and an
apparatus for the formation of a metal film containing no residual
impurities can be obtained. Moreover, chlorine can be removed by
reduction in a short period of time, resulting in a further
improvement in the rate of film growth.
[0069] According to still a further embodiment of the present
invention, there is provided a method for the formation of a metal
film which comprises reacting chlorine with a metallic plate within
a chamber to produce a precursor composed of a metallic component
and chlorine, removing chlorine from the precursor by reduction,
and directing the resulting metallic ion onto a substrate within
the chamber to form a metal film on the substrate, the method being
characterized in that the chamber is heated to a predetermined
temperature so as to prevent the precursor from depositing on the
inner wall of the chamber and, moreover, the metallic plate is
heated to a predetermined temperature so as to make the precursor
easy to reduce. Thus, the precursor is prevented from depositing on
the inner wall of the chamber and, moreover, a monomeric precursor
which can be easily reduced tends to be produced. Consequently, a
high rate of film growth can be achieved, an inexpensive raw
material can be used, and an apparatus for the formation of a metal
film containing no residual impurities can be obtained. Moreover,
the necessity of cleaning the inside of the chamber periodically
can be eliminated to cause an improvement in raw material
efficiency and a reduction in running cost. Furthermore, chlorine
can be removed by reduction in a short period of time, resulting in
a further improvement in the rate of film growth.
[0070] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising: [0071] a reaction vessel in
which a substrate to be treated is placed; [0072] an inlet vessel
disposed within the reaction vessel and equipped with a copper
discharge plate having a plurality of discharge orifices bored
therethrough; [0073] temperature control means attached to the
copper discharge plate; [0074] a raw material gas feed pipe
inserted into the inlet vessel for feeding chlorine or hydrogen
chloride; [0075] plasma generating means for generating a plasma of
chlorine or hydrogen chloride within the inlet vessel; [0076]
atomic reducing gas producing means for producing an atomic
reducing gas within the reaction vessel, at least in the
neighborhood of the substrate to be treated; and [0077] evacuation
means for evacuating any gas from the reaction vessel and the inlet
vessel.
[0078] According to still a further embodiment of the present
invention, there is provided an apparatus for the formation of a
metal film, the apparatus comprising: [0079] a reaction vessel in
which a substrate to be treated is placed; [0080] a raw material
gas feed pipe inserted into the inlet vessel for feeding chlorine
or hydrogen chloride; [0081] a spiral tube attached to the inner
end of the raw material gas feed pipe, having a raw material gas
flow passage whose inner surface is made of copper, and equipped
with a heating element; [0082] atomic reducing gas producing means
for producing an atomic reducing gas within the reaction vessel, at
least in the neighborhood of the substrate to be treated; and
[0083] evacuation means for evacuating any gas from the reaction
vessel and the raw material gas flow passage.
[0084] As specifically described above, the present invention makes
it possible to achieve a high rate of film growth while using
inexpensive chlorine or hydrogen chloride as a raw material gas,
and to form a thin-copper film of good quality containing little
residual impurities and having a desired film thickness, with good
reproducibility. Thus, the present invention can provide an
apparatus for the vapor phase growth of a thin copper film which is
useful, for example, in the formation of wiring material films for
use in semiconductor devices and liquid crystal displays.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] FIG. 1 is a schematic view of a plasma-excited vapor phase
growth apparatus for use in a first embodiment of the present
invention;
[0086] FIG. 2 is a schematic view of a plasma-excited vapor phase
growth apparatus for use in a second embodiment of the present
invention;
[0087] FIG. 3 is a schematic view of a plasma-excited vapor phase
growth apparatus for use in a third embodiment of the present
invention;
[0088] FIG. 4 is a schematic view of a plasma-excited vapor phase
growth apparatus for use in a fourth embodiment of the present
invention;
[0089] FIG. 5 is a plan view of a meshlike electrode for use in the
fourth embodiment of the present invention;
[0090] FIG. 6 is a plan view of a ladderlike electrode for use in
the fourth embodiment of the present invention;
[0091] FIG. 7 is a plan view of a comblike electrode for use in the
fourth embodiment of the present invention;
[0092] FIG. 8 is a plan view of a punching board type electrode for
use in the fourth embodiment of the present invention;
[0093] FIG. 9 is a schematic view of a plasma-excited vapor phase
growth apparatus for use in a fifth embodiment of the present
invention;
[0094] FIG. 10 is a schematic side view of an apparatus for the
formation of a metal film in accordance with a sixth embodiment of
the present invention;
[0095] FIG. 11 is a schematic side view of an apparatus for the
formation of a metal film in accordance with a seventh embodiment
of the present invention;
[0096] FIG. 12 is a schematic side view of an apparatus for the
formation of a metal film in accordance with an eighth embodiment
of the present invention;
[0097] FIG. 13 is a schematic side view of an apparatus for the
formation of a metal film in accordance with a ninth embodiment of
the present invention;
[0098] FIG. 14 is a schematic side view of an apparatus for the
formation of a metal film in accordance with a tenth embodiment of
the present invention;
[0099] FIG. 15 is a schematic side view of an apparatus for the
formation of a metal film in accordance with an eleventh embodiment
of the present invention;
[0100] FIG. 16 is a schematic side view of an apparatus for the
formation of a metal film in accordance with a twelfth embodiment
of the present invention;
[0101] FIG. 17 is a schematic sectional view of an apparatus for
the vapor phase growth of a thin copper film in accordance with a
thirteenth embodiment of the present invention;
[0102] FIG. 18 is a plan view of the copper discharge plate
incorporated in the vapor phase growth apparatus of FIG. 17;
[0103] FIG. 19 is a schematic sectional view of an apparatus for
the vapor phase growth of a thin copper film in accordance with a
fourteenth embodiment of the present invention;
[0104] FIG. 20 is a view of one form of the spiral tube
incorporated in the vapor phase growth apparatus of FIG. 19;
[0105] FIG. 21 is a view of another form of the spiral tube
incorporated in the vapor phase growth apparatus of FIG. 19;
[0106] FIG. 22 is a schematic view of a conventional apparatus for
the vapor phase growth of a thin noble metal film; and
[0107] FIG. 23 is a schematic sectional view of a conventional
apparatus for the vapor phase growth of a thin copper film.
BEST MODE FOR CARRYING OUT THE INVENTION
[0108] Various embodiments of the present invention will be
specifically described hereinbelow with reference to the
accompanying drawings.
First Embodiment
[0109] FIG. 1 is a schematic view of a plasma-excited vapor phase
growth apparatus for the formation of a thin noble metal film in
accordance with a first embodiment of the present invention.
[0110] This plasma-excited vapor phase growth apparatus 51 includes
a reaction vessel 1 formed into the shape of a box; first and
second plasma generators 52,53 disposed on the upper and lower
sides of reaction vessel 1; and a rotating magnetic field coil 4, 4
disposed on the side of reaction vessel 1.
[0111] Moreover, an inlet vessel 11 for receiving a raw material
gas 55 is disposed in the upper part of the aforesaid reaction
vessel 1. A flow controller 3 and a nozzle 2 are connected to the
sidewall of inlet vessel 11, and a perforated plate 12 made of Cu
and having a plurality of holes 12a bored therethrough is disposed
at the bottom thereof. Furthermore, rotating magnetic field coil 4,
4 disposed on the side of reaction vessel 1 creates a rotating
magnetic field in the lower part of reaction vessel 1, and this
rotating magnetic field causes a metal such as Cu to receive a
force directed toward a substrate 15 and thereby travel in an
accelerated manner. In the lowermost part of reaction vessel 1, a
heater 16 is disposed so as to be spaced from perforated plate 12,
and substrate 15 is placed on this heater 16. At the lower end of
reaction vessel 1 and below rotating magnetic field coil 4, a
reducing gas flow controller 6 and a reducing gas inlet nozzle 5
are disposed in order to feed a reducing gas 60 comprising hydrogen
gas into the interior of reaction vessel 1. First plasma generator
52 consists of an insulating plate 9 disposed on the top surface 58
of reaction vessel 1, a first plasma antenna 8 disposed on
insulating plate 9, and a first plasma power supply 7. Second
plasma generator 53 has the same construction as first plasma
generator 52. The bottom wall 56 of reaction vessel 1 has an
exhaust port 57 bored therethrough.
[0112] Now, the operation of plasma-excited vapor phase growth
apparatus 51 having the above-described construction is described
below.
[0113] First of all, Cl.sub.2 gas used as raw material gas 55 is
passed through flow controller 3 in order to control its flow rate,
and then introduced into inlet vessel 11 through nozzle 2.
Subsequently, the raw material gas comprising Cl.sub.2 gas is
converted into a plasma by means of first plasma antenna 8 which is
energized by first plasma power supply 7, so that a raw material
gas plasma 10 comprising Cl.sub.2 plasma is generated within inlet
vessel 11. Since the material of perforated plate 12 contains Cu,
this Cl.sub.2 plasma actively causes an etching reaction of
perforated plate 12 made of Cu, resulting in the production of a
precursor (Cu.sub.xCl.sub.y) 13. This precursor (Cu.sub.xCl.sub.y)
13 is discharged-downward through the plurality of holes 12a of
perforated plate 12. Thereafter, under the action of the rotating
magnetic field created by rotating magnetic field coil 4,4,
precursor 13 is accelerated and conveyed toward substrate 15 placed
on heater 16. Immediately before precursor 13 arrives at substrate
15, it passes through a reducing gas plasma 14 comprising H.sub.2
plasma produced by means of second plasma antenna 18 which is
energized by second plasma power supply 19. Thus, the aforesaid
precursor 13 undergoes a reduction reaction with atomic hydrogen to
form a thin Cu film 62 on substrate 15. The extent to which this
thin Cu film 62 is formed depends on the uniformity of the rotating
magnetic field.
[0114] Alternatively, HCl gas may be used as the aforesaid raw
material gas 55. In this case, HCl plasma is produced as raw
material gas plasma 10, but precursor 13 produced by an etching
reaction of perforated plate 12 made of Cu is Cu.sub.xCl.sub.y.
Accordingly, raw material gas 55 may comprise any gas containing
chlorine, and a mixed gas composed of HCl gas and Cl.sub.2 gas may
also be used. The extent to which a thin film can be stably formed
depends on the uniformity of the rotating magnetic field.
Second Embodiment
[0115] FIG. 2 is a schematic view of a plasma-excited vapor phase
growth apparatus 65 for the formation of a thin noble metal film in
accordance with a second embodiment of the present invention. Since
some components of this apparatus 65 have the same structure as
those of plasma-excited vapor phase growth apparatus 51 used in the
above-described first embodiment, these components are designated
by the same reference numerals and the explanation thereof is
omitted.
[0116] Plasma-excited vapor phase growth apparatus 65 used in the
second embodiment includes a reaction vessel 1 formed into the
shape of a box; a first plasma generator 52 disposed on the upper
side of reaction vessel 1; and a reducing gas heating device 66 for
heating a reducing gas (e.g., hydrogen gas) 55 to produce an atomic
gas. When compared with plasma-excited vapor phase growth apparatus
51 used in the above-described first embodiment, this
plasma-excited vapor-phase growth apparatus 65 differs in having
reducing gas heating device 66.
[0117] This reducing gas heating device 66 consists of a reducing
gas flow controller 6, a reducing gas inlet nozzle 5 attached
thereto, and a tungsten filament disposed within reducing gas inlet
nozzle 5. The ends of the tungsten filament are connected to a
direct-current power supply 24.
[0118] The operation of plasma-excited vapor phase growth apparatus
65 having the above-described construction is described below.
[0119] First of all, Cl.sub.2 gas used as raw material gas 55 is
passed through flow controller 3 in order to control its flow rate,
and then introduced into inlet vessel 11 through nozzle 2. Thus,
the C1.sub.2 gas is converted into a plasma by means of plasma
antenna 8 which is energized by plasma power supply 7, so that a
raw material gas plasma 10 comprising Cl.sub.2 plasma is generated.
This Cl.sub.2 plasma actively causes an etching reaction of
perforated plate 12 made of Cu, resulting in the production of a
precursor (Cu.sub.xCl.sub.y) 13 within inlet vessel 11. This
precursor (Cu.sub.xCl.sub.y) 13 is discharged downward through the
plurality of holes 12a of perforated plate 12. Immediately before
precursor 13 arrives at substrate 15, a reducing gas 60 comprising
H.sub.2 gas is passed through reducing gas flow controller 6 in
order to control its flow rate, tungsten filament 23 is heated to
1,800.degree. C. by means of direct-current power supply 24 to
produce an atomic reducing gas 25 comprising atomic.hydrogen, and
this atomic reducing gas 25 is injected into reaction vessel 1
through reducing gas inlet nozzle 5. Thus, precursor 13 undergoes a
reduction reaction with atomic hydrogen to form a thin Cu film 62
on substrate 15.
[0120] Alternatively, HCl gas may be used as the aforesaid raw
material gas 55. In this case, HCl plasma is produced as raw
material gas plasma 10, but precursor 13 produced by an etching
reaction of perforated plate 12 made of Cu is Cu.sub.xCl.sub.y.
Accordingly, raw material gas 55 may comprise any gas containing
chlorine, and a mixed gas composed of HCl gas and Cl.sub.2 gas may
also be used.
[0121] Since atomic reducing gas 25 comprising atomic hydrogen can
be fed simply by use of reducing gas inlet nozzle 5 which permits a
relatively flexible arrangement, a film having an area up to about
50 mm.times.50 mm can be stably formed.
Third Embodiment
[0122] FIG. 3 is a schematic view of a plasma-excited vapor phase
growth apparatus 70 for the formation of a thin noble metal film in
accordance with a third embodiment of the present invention. Since
some components of this apparatus 70 have the same structure as
those of plasma-excited vapor phase growth apparatus 51,65 used in
the above-described first and second embodiments, these components
are designated by the same reference numerals and the explanation
thereof is omitted.
[0123] Plasma-excited vapor phase growth apparatus 70 used in the
third embodiment includes a reaction vessel 1 formed into the shape
of a box; a raw material gas heating device 71 disposed in the
upper part of reaction vessel 1; and a reducing gas heating device
66 disposed in the upper part of reaction vessel 1. When compared
with plasma-excited vapor phase growth apparatus 65 used in the
above-described second embodiment, this plasma-excited vapor phase
growth apparatus 70 differs in having raw material gas heating
device 71.
[0124] This raw material gas heating device 71 consists of a flow
controller 3, a nozzle 2 attached thereto, and a copper filament
comprising several turns of copper wire and disposed within nozzle
2. The ends of copper filament 26 are connected to a direct-current
power supply 27.
[0125] The operation of plasma-excited vapor phase growth apparatus
70 having the above-described construction is described below.
[0126] First of all, Cl.sub.2 gas used as raw material gas 55 is
passed through flow controller 3 in order to control its flow rate,
and then fed into raw material gas inlet nozzle 2. This raw
material gas inlet nozzle 2 is provided therein with copper
filament 26 which has been heated to 300-600.degree. C. by
supplying an electric current from direct-current power supply 27
and passing it therethrough. Thus, the aforesaid Cl.sub.2 gas is
brought into efficient contact with copper filament 26 to produce a
precursor 13. When this precursor 13 is introduced into reaction
vessel 1 through raw material gas inlet nozzle 2, precursor 13
moves downward.
[0127] Now, a reducing gas 60 comprising H.sub.2 gas is passed
through reducing gas flow controller 6 in order to control its flow
rate, and then fed into reducing gas inlet nozzle 5. This reducing
gas inlet nozzle 5 is provided therein with tungsten filament 23.
When tungsten filament 23 is heated to about 1,800.degree. C. by
supplying an electric current from direct-current power supply 24
and passing it therethrough, an atomic reducing gas 25 comprising
atomic hydrogen is produced from reducing gas 60. Immediately
before precursor 13 arrives at substrate 15, the atomic hydrogen is
injected into reaction vessel 1 through reducing gas inlet nozzle
5. Thus, the aforesaid precursor 13 undergoes a reduction reaction
with the atomic hydrogen to form a thin Cu film 62 on substrate
15.
[0128] The aforesaid raw material gas 55 may comprise any gas
containing chlorine. For example, there may be used HCl gas or a
mixed gas composed of HCl gas and Cl.sub.2 gas.
[0129] Since the above-described method can feed precursor 13 and
atomic hydrogen simply by use of gas nozzle 5 which permits a
relatively flexible arrangement, a film having an area up to about
100 mm.times.100 mm can be stably formed.
Fourth Embodiment
[0130] FIG. 4 is a schematic view of a plasma-excited vapor phase
growth apparatus 85 for the formation of a thin noble metal film in
accordance with a fourth embodiment of the present invention. Since
some-components of this apparatus 85 have the same structure as
those of plasma-excited vapor phase growth apparatus 51 used in the
above-described first embodiment, these components are designated
by the same reference numerals and the explanation thereof is
omitted. The aforesaid plasma-excited vapor phase growth apparatus
85 is characterized by the fact that, in plasma-excited vapor phase
growth apparatus 51 in accordance with the first embodiment,
high-frequency electric power is utilized to generate a reducing
plasma. Specifically, this apparatus 85 is constructed by
eliminating rotating magnetic field coil 4, insulating plate 17,
second plasma antenna 18 and second plasma power supply 19 from the
plasma-excited vapor phase growth apparatus 51 of FIG. 1 and
instead adding an electrode connected to a high-frequency power
supply. No modification is made in the components associated with
the production of precursor 13, the feeding of hydrogen gas used as
reducing gas 60, and the disposition of substrate 15.
[0131] Within reaction vessel 1, the aforesaid plasma-excited vapor
phase growth apparatus 85 includes a reducing plasma generating
electrode 71 disposed between perforated plate 12 and heater 16. It
also includes a high-frequency power supply 76, a matching
transformer 75 and an electric current input terminal 73 which are
all disposed on the outside of reaction vessel 1. These
high-frequency power supply 76, matching transformer 75 and
electric current input terminal 73 are connected together by
coaxial cables 74, and electric current input terminal 73 and
reducing plasma generating electrode 71 are connected together by a
feeder 72.
[0132] As the aforesaid reducing plasma generating electrode 71, an
electrode in the form of a flat plate having a multitude of holes
is used so that the flux of precursor 13 may not be prevented from
traveling toward substrate 15. For example, there may be used a
circular meshlike electrode 77 as illustrated in FIG. 5. This
meshlike electrode 77 consists of a metal mesh 77a formed of woven
metal wires and disposed inside, and a mesh-holding jig 77b for
fastening the periphery of metal mesh 77a so as to prevent it from
being frayed. This mesh-holding jig 77b comprises, for example, an
annulus which is made of the same material as that of metal mesh
77a and used to fasten metal mesh 77a by sandwiching it from the
upper and lower sides.
[0133] It is to be understood that the aforesaid reducing plasma
generating electrode 71 is not limited to meshlike electrode 77,
but various types of electrodes may be used, provided that they
have a shape which does not prevent the flux of precursor 13 from
traveling toward substrate 15.
[0134] For example, a ladderlike electrode 79 as illustrated in
FIG. 6, a comblike electrode 80 as illustrated in FIG. 7, and a
punching board type electrode 81 may preferably be used.
[0135] The aforesaid ladderlike electrode 79 is formed by arranging
a pair of vertical wires 79a in parallel and disposing a plurality
of horizontal wires 79b between vertical wires 79a,79a. The
aforesaid comblike electrode 80 is formed by providing two units
each consisting of one vertical wire 80a having a plurality of
horizontal wires 80b attached thereto, and arranging these two
units in interdigitated relationship. The aforesaid punching board
type electrode 81 is formed by boring a plurality of small holes 83
in a circular metallic board 82.
[0136] In the above-described electrodes, no particular limitation
is placed on the diameter and number of wires constituting metal
mesh 77a, and the pitch of the mesh, in meshlike electrode 77; the
diameter, number and spacing of horizontal wires in ladderlike
electrode 79; the diameter, number and spacing of vertical and
horizontal wires 80a,80b, and the number of units, in comblike
electrode 80; the diameter, number and arrangement of holes bored
in board 82 constituting punching board type electrode 81; and the
degree of opening of the electrode. Accordingly, the shape of the
electrode may be suitably chosen according to the type of the
desired reducing action.
[0137] An electrically conductive material is used for these
electrodes. However, the reaction vessel has an atmosphere of
chlorine, it is desirable to use stainless steel or the like for
the purpose of preventing corrosion.
[0138] The operation of the above-described plasma-excited vapor
phase growth apparatus 85 is described below.
[0139] The process occurring until precursor 13 is discharged
through the holes 12a of perforated plate 12 is the same as
described in connection with the first embodiment. Then,
high-frequency power supply 76 applies high-frequency electric
power to reducing plasma generating electrode 71 by way of matching
transformer 75 and electric current input terminal 73. Thus, a
reducing gas plasma 14 comprising hydrogen plasma is generated over
the entire surface of the aforesaid reducing plasma generating
electrode 71. When precursor 13 passes through the hydrogen plasma,
it undergoes a reduction reaction with atomic hydrogen to form a
thin Cu film 62 on substrate 15.
Fifth Embodiment
[0140] FIG. 9 is a schematic view of a plasma-excited vapor phase
growth apparatus 90 for the formation of a thin noble metal film in
accordance with a fifth embodiment of the present invention. This
apparatus 90 is based on the combination of plasma-excited vapor
phase growth apparatus 85 used in the above-described fourth
embodiment (see FIG. 4) with a convention method for feeding a raw
material gas (see FIG. 10). The components having the same
structure are designated by the same reference numerals and the
explanation thereof is omitted.
[0141] In the aforesaid plasma-excited vapor phase growth apparatus
90, a raw material vessel 121 is connected to a vaporizer 120 via a
flow controller 103. Moreover, the aforesaid raw material vessel
121 is provided with a bubbling pipe for producing a vapor of
liquid raw material 122 .contained therein. Further more, this
apparatus 90 is equipped with a device for utilizing high-frequency
electric power to generate a reducing gas plasma 14 and thereby
subjecting precursor 13 to a reduction reaction, as illustrated in
FIG. 4.
[0142] The operation of plasma-excited vapor phase growth apparatus
90 having the above-described construction is described below.
[0143] First of all, a liquid raw material 122 comprising, for
example, copper hexafluoroacetylacetonato-trimethylvinylsilane
[Cu(hfac)(tmvs)] is contained in raw material vessel 121 and a
carrier gas comprising He is bubbled therethrough. Liquid raw
material 122 is not limited thereto, but may comprise any desired
liquid organometallic complex. The raw material evaporated by
bubbling is passed through flow controller 103 to control its flow
rate, and then fed into vaporizer 120. After the aforesaid raw
material is completely vaporized in vaporizer 120, the resulting
precursor 113 is introduced into the interior of reaction vessel 1
through perforated plate 112. Now similarly to the fourth
embodiment, a reducing gas plasma 14 comprising hydrogen plasma is
generated by means of high-frequency electric power. Consequently,
when the aforesaid precursor 113 passes through the hydrogen
plasma, precursor 113 undergoes a reduction reaction to form a thin
Cu film 62 on substrate 15.
[0144] Next, an apparatus and method for the formation of a metal
film in accordance with a sixth embodiment of the present invention
is described with reference to FIG. 10. FIG. 10 is a schematic side
view of the apparatus for the formation of a metal film in
accordance with the sixth embodiment of the present invention.
[0145] As illustrated in FIG. 10, this apparatus includes a chamber
201 made, for example, of stainless steel and formed into the shape
of a box; a first plasma generating means 202 disposed on the upper
side of chamber 201; and a second plasma generating means 203
disposed on the lower side of chamber 201. This apparatus also
includes a magnetic field coil 204 disposed on the side of chamber
201. First plasma generating means 202 consists of a first
insulating plate 221 disposed on the top surface of chamber 201, a
first plasma antenna 222 disposed on first insulating plate 221,
and a first power supply 223 for energizing first plasma antenna
222. Second plasma generating means 203 consists of a second
insulating plate 224 disposed on the bottom surface of chamber 201,
a second plasma antenna 225 disposed on second insulating plate
225, and a second power supply 226 for energizing second plasma
antenna 225.
[0146] Within chamber 201, an inlet vessel 206 is disposed under
first insulating plate 221, and a raw material gas 205 comprising
chlorine gas (Cl.sub.2 gas) is fed into inlet vessel 206. A flow
controller 207 and a nozzle 208 are connected to the sidewall of
inlet vessel 206, and a discharge plate (or metallic plate) 209
made of Copper (Cu) is disposed at the bottom of inlet vessel 206.
This discharge plate 209 has a multitude of discharge orifices 210
bored therethrough. A support 211 is disposed near the bottom of
chamber 201 and a substrate 212 is placed on this support 211.
Support 211 is heated to a predetermined temperature by a heater
means (not shown). At the lower end of chamber 201 and below
magnetic field coil 204, a reducing gas flow controller 214 and a
reducing gas nozzle 215 are disposed in order to feed a reducing
gas 213 comprising hydrogen gas (H.sub.2 gas) into the interior of
chamber 201. Furthermore, the bottom wall of chamber 201 has an
exhaust port 227 bored therethrough.
[0147] On the other hand, the sidewall of chamber 201 is provided
with a filament type heater 228 serving as a chamber heating means.
By using a power supply 229 to energize this heater 228, the
sidewall of chamber 201 is heated to a predetermined temperature,
for example, in the range of 200 to 600.degree. C. It is preferable
that the upper limit of the predetermined temperature is not higher
than the durable temperature of chamber 201. Since this embodiment
is described in connection with chamber 201 made of stainless
steel, the upper temperature limit is set at 600.degree. C. Thus,
the upper limit of the predetermined temperature may be suitably
determined according to the material of chamber 201.
[0148] Even if the precursor (Cu.sub.xCl.sub.y) which will be
described later adheres to the sidewall of chamber 201, it will
readily be vaporized because the sidewall of chamber 201 is heated
to cause a rise in the vapor pressure of the precursor.
Consequently, the precursor (Cu.sub.xCl.sub.y) is prevented from
depositing on the sidewall of chamber 201. Since this embodiment is
described in connection with discharge plate 209 made of Cu, the
lower limit of the predetermined temperature is set at 200.degree.
C. Thus, the lower limit of the predetermined temperature may be
suitably determined according to the type of the precursor produced
on the basis of the material of discharge plate 209.
[0149] In the above-described apparatus for the formation of a
metal film, Cl.sub.2 gas is fed into inlet vessel 206. When
electromagnetic waves are radiated into inlet vessel 206 by first
plasma antenna 222 of first plasma generating means 202, the
Cl.sub.2 gas within inlet vessel 206 is ionized to generate
Cl.sub.2 gas plasma (raw material gas plasma) 231. This Cl.sub.2
gas plasma 231 causes an etching reaction of discharge plate 209
made of Cu, so that a precursor (Cu.sub.xCl.sub.y) 230 is produced.
This precursor (Cu.sub.xCl.sub.y) 230 is discharged downward
through discharge orifices 210.
[0150] On the other hand, H.sub.2 gas is introduced into chamber
201. When electromagnetic waves are radiated into chamber 201 by
second plasma antenna 225 of second plasma generating means 203,
the H.sub.2 gas within chamber 201 is ionized to generate H.sub.2
gas plasma (reducing gas plasma) 232. Owing to a rotating magnetic
field created by magnetic field coil 204, this H.sub.2 gas plasma
232 is densely and uniformly distributed in the neighborhood of the
surface of substrate 212.
[0151] Immediately before precursor (Cu.sub.xCl.sub.y) 230
discharged downward through discharge orifices 210 arrives at
substrate 212, it passes through H.sub.2 gas plasma 232. While
precursor (Cu.sub.xCl.sub.y) 230 passes through H.sub.2 gas plasma
232 serving as a reducing gas plasma, chlorine is removed therefrom
by a reduction reaction with atomic hydrogen. The resulting Cu ions
are directed onto substrate 212 to form a thin Cu film 233 on the
surface of substrate 212.
[0152] Since the sidewall of chamber 201 is heated to a
predetermined temperature (e.g., 200.degree. C.) by heater 228,
precursor (Cu.sub.xCl.sub.y) 230 adhering to the sidewall of
chamber 201 will readily be vaporized because of its raised vapor
pressure. Consequently, precursor (Cu.sub.xCl.sub.y) 230 is
prevented from depositing on the sidewall of chamber 201. It has
been confirmed that, if the sidewall of chamber 201 has a
temperature lower than the predetermined temperature (e.g.,
180.degree. C. or so), the vapor pressure of precursor
(Cu.sub.xCl.sub.y) 230 will not rise sufficiently and, therefore,
precursor (Cu.sub.xCl.sub.y) 230 will deposit on the sidewall of
chamber 201.
[0153] In the above-described apparatus for the formation of a
metal film, chlorine gas (Cl.sub.2 gas) is used as an example of
raw material gas 205. However, HCl gas may also be used. In this
case, HCl gas plasma is generated as the raw material gas plasma,
but precursor 230 produced by the etching of discharge plate 209
made of Cu is Cu.sub.xCl.sub.y. Accordingly, raw material gas 205
may comprise any gas containing chlorine, and a mixed gas composed
of HCl gas and Cl.sub.2 gas may also be used. Moreover, the
material of discharge plate 209 is not limited to Cu, but Ag, Au,
Pt, Ti, W and the like may also be used. In this case, precursor
230 comprises a chloride of Ag, Au, Pt, Ti, W or the like, and the
thin film formed on the surface of substrate 212 comprises Ag, Au,
Pt, Ti, W or the like.
[0154] Since two plasmas, namely Cl.sub.2 gas plasma (raw material
gas plasma) 231 and H.sub.2 gas plasma (reducing gas plasma) 232,
are used in the above-described apparatus for the formation of a
metal film, the reaction efficiency is markedly improved to cause
an increase in rate of film growth. Moreover, since chlorine gas
(Cl.sub.2 gas) is used as raw material gas 205 and a
hydrogen-containing gas is used as reducing gas 213, a marked
reduction in cost is achieved. Furthermore, since the reduction
reaction can be accelerated independently, the amount of impurities
(e.g., chlorine) remaining in thin Cu film 233 can be minimized to
form a thin Cu film 233 of high quality.
[0155] In addition, since the sidewall of chamber 201 is heated to
a predetermined temperature by heater 228, precursor
(Cu.sub.xCl.sub.y) 230 adhering to the sidewall of chamber 201 will
readily be vaporized because of its raised vapor pressure. Thus,
precursor (Cu.sub.xCl.sub.y) 230 is prevented from depositing on
the sidewall of chamber 201. Consequently, the necessity of
cleaning the inside of chamber 201 periodically can be eliminated
to cause an improvement in raw material efficiency and a reduction
in running cost.
[0156] Now, an apparatus and method for the formation of a metal
film in accordance with a seventh embodiment of the present
invention is described with reference to FIG. 11. FIG. 11 is a
schematic side view of the apparatus for the formation of a metal
film in accordance with the seventh embodiment of the present
invention. The same components as those shown in FIG. 10 are
designated by the same reference numerals and the duplicate
explanation thereof is omitted.
[0157] When compared with the apparatus for the formation of a
metal film as illustrated in FIG. 10, the apparatus for the
formation of a metal film in accordance with the seventh embodiment
as illustrated in FIG. 11 does not include the chamber heating
means comprising filament type heater 228 and power supply 229, but
includes a discharge plate heating means for heating discharge
plate 209. Specifically, discharge plate (or metallic plate) 209
made of Copper (Cu) is provided at the bottom of inlet vessel 206
through the medium of an insulating member 241. An auxiliary nozzle
242 for feeding a rare gas comprising He gas is connected to the
sidewall of inlet vessel 206. Thus, He gas is fed into inlet vessel
206 together with raw material gas 205 comprising chlorine gas
(Cl.sub.2 gas). Cl.sub.2 gas and He gas are fed into inlet vessel
206 in a ratio of approximately 1:1. A biasing power supply 243 is
connected to discharge plate 209, so that a direct-current voltage
is applied to discharge plate 209 by biasing power supply 243.
[0158] In the above-described apparatus for the formation of a
metal film, when electromagnetic waves are radiated into inlet
vessel 206 by first plasma antenna 222 of first plasma generating
means 202, the Cl.sub.2 gas and He gas within inlet vessel 206 are
ionized to generate Cl.sub.2--He gas plasma 244. This Cl.sub.2--He
gas plasma 244 causes He ions to collide with discharge plate 209
to which a bias voltage is applied. Thus, discharge plate 209 is
uniformly heated. As the means for heating discharge plate 209, a
heater or other means for heating discharge plate 209 directly may
also be used in place of the means based on the collision of He
ions.
[0159] The heating temperature of discharge plate 209 is, for
example, in the range of 200 to 800.degree. C. and preferably
600.degree. C. It is preferable that the lower limit of the heating
temperature is a temperature at which precursor (Cu.sub.xCl.sub.y)
230 passing through discharge orifices 210 becomes a monomeric
compound rather than a polymeric one when discharge plate 209 is
heated to 600.degree. C., precursor 230 tends to be monomeric CuCl
and this facilitates the reduction reaction which will be described
later. The upper limit of the heating temperature depends on the
material of discharge plate 209. In the case of discharge plate 209
made of copper (Cu), the upper limit is 800.degree. C. If the
heating temperature exceeds 800.degree. C., discharge plate 209
cannot be used because of its softening. Discharge plate 209 can be
adjusted to a desired temperature by controlling the voltage
applied to discharge plate 209.
[0160] When Cl.sub.2--He gas plasma 244 is generated within inlet
vessel 206, the Cl.sub.2 gas plasma causes an etching reaction of
the heated discharge plate 209 made of Cu, so that a monomeric
precursor (CuCl) 230 tends to be produced. The resulting precursor
(CuCl) 230 is discharged downward through discharge orifices 210 of
discharge plate 209. Immediately before precursor (CuCl) 230
discharged downward through discharge orifices 210 arrives at
substrate 212, it passes through H.sub.2 gas plasma 232. Thus,
chlorine is removed therefrom by a reduction reaction with atomic
hydrogen. The resulting Cu ions are directed onto substrate 212 to
form a thin Cu film 233 on the surface of substrate 212.
[0161] Since precursor 230 discharged downward comprises monomeric
CuCl, it can readily be reduced by atomic hydrogen. Thus, chlorine
is removed therefrom by reduction in a short period of time.
Consequently, the resulting Cu ions are directed onto substrate 212
to form a thin Cu film 233 on the surface of substrate 212 in a
short period of time. That is, since discharge plate 209 is
uniformly heated to a desired temperature by the collision of He
ions, a monomeric precursor (CuCl) 230 which can readily be reduced
is produced. This makes it possible to remove chlorine by reduction
in a short period of time and thereby improve the rate of film
growth.
[0162] Now, an apparatus and method for the formation of a metal
film in accordance with an eighth embodiment of the present
invention is described with reference to FIG. 12. FIG. 12 is a
schematic side view of the apparatus for the formation of a metal
film in accordance with the eighth embodiment of the present
invention. The same components as those shown in FIGS. 10 and 11
are designated by the same reference numerals and the duplicate
explanation thereof is omitted.
[0163] When compared with the apparatus for the formation of a
metal film as illustrated in FIG. 11, the apparatus for the
formation of a metal film in accordance with the eighth embodiment
as illustrated in FIG. 12 includes a chamber heating means
comprising a filament type heater 228 and a power supply 229. That
is, this apparatus is equipped with both the chamber heating means
and the discharge plate heating means.
[0164] Thus, since the sidewall of chamber 201 is heated to a
predetermined temperature (e.g., 200.degree. C.) by heater 228,
precursor (CuCl) 230 adhering to the sidewall of chamber 201 will
readily be vanorized because of its raised vapor pressure.
Consequently, precursor (CuCl) 230 is prevented from depositing on
the sidewall of chamber 201. Moreover, since precursor 230
discharged downward comprises monomeric CuCl, it can readily be
reduced by atomic hydrogen. Thus, chlorine is removed therefrom by
reduction in a short period of time. Consequently, the resulting Cu
ions are directed onto substrate 212 to form a thin Cu film 233 on
the surface of substrate 212 in a short period of time.
[0165] Accordingly, since the sidewall of chamber 201 is heated to
a predetermined temperature by heater 228, precursor (CuCl) 230
adhering to the sidewall of chamber 201 will readily be vaporized
because of its raised vapor pressure. Thus, precursor (CuCl) 230 is
prevented from depositing on the sidewall of chamber 201.
Consequently, the necessity of cleaning the inside of chamber 201
periodically can be eliminated to cause an improvement in raw
material efficiency and a reduction in running cost. Moreover,
since discharge plate 209 is uniformly heated to a desired
temperature by the collision of He ions, a monomeric precursor
(CuCl) 230 which can readily be reduced is produced. This makes it
possible to remove chlorine by reduction in a short period of time
and thereby improve the rate of film growth.
[0166] Now, an apparatus and method for the formation of a metal
film in accordance with a ninth embodiment of the present invention
is described with reference to FIG. 13. FIG. 13 is a schematic side
view of the apparatus for the formation of a metal film in
accordance with the ninth embodiment of the present invention. The
same components as those shown in FIG. 10 are designated by the
same reference numerals and the duplicate explanation thereof is
omitted.
[0167] When compared with the apparatus for the formation of a
metal film as illustrated in FIG. 10, the apparatus for the
formation of a metal film in accordance with the ninth embodiment
as illustrated in FIG. 13 is characterized in that an atomic
reducing gas 251 id produced in place of the reducing gas plasma
comprising H.sub.2 gas plasma 232. To this end, this apparatus
includes a reducing gas heating means 252 for heating a reducing
gas (e.g., H.sub.2 gas) 213 to produce an atomic reducing gas 251,
in place of second plasma generating means 203. This reducing gas
heating means 252 consists of a reducing gas flow controller 214, a
reducing gas nozzle 215 attached thereto, and tungsten filament 253
disposed within reducing gas nozzle 215. The ends of tungsten
filament 215 are connected to a direct-current power supply
254.
[0168] In the above-described apparatus for the formation of a
metal film, Cl.sub.2 gas is fed into inlet vessel 206. When
electromagnetic waves are radiated into inlet vessel 206 by first
plasma antenna 222 of first plasma generating means 202, the
Cl.sub.2 gas within inlet vessel 206 is ionized to generate
Cl.sub.2 gas plasma (raw material gas plasma) 231. This Cl.sub.2
gas plasma 231 causes an etching reaction of discharge plate 209
made of Cu, so that a precursor (Cu.sub.xCl.sub.y) 230 is produced.
This precursor (Cu.sub.xCl.sub.y) 230 is discharged downward
through discharge orifices 210.
[0169] Immediately before precursor (Cu.sub.xCl.sub.y) 230 arrives
at substrate 212, a reducing gas 213 comprising H.sub.2 gas is
passed through reducing gas flow controllers 214 in order to
control its flow rate, and tungsten filament 253 is heated to
1,800.degree. C. by means of direct-current power supply 254. As a
result of the hearing of tungsten filament 253, an atomic reducing
gas 251 (atomic hydrogen) is produced and injected into chamber 201
through reducing gas inlet nozzle 215. Consequently, precursor
(Cu.sub.xCl.sub.y) 230 discharged downward through discharge
orifices 210 passes through atomic reducing gas 251 immediately
before arriving at substrate 212. Thus, chlorine is removed from
precursor (Cu.sub.xCl.sub.y) 230 by a reduction reaction with
atomic hydrogen. The resulting Cu ions are directed onto substrate
212 to form a thin Cu film 233 on the surface of substrate 212.
[0170] Since the sidewall of chamber 201 is heated to a
predetermined temperature (e.g., 200.degree. C.) by heater 228,
precursor (Cu.sub.xCl.sub.y) 230 adhering to the sidewall of
chamber 201 will readily be vaporized because of its raised vapor
pressure. Consequently, precursor (Cu.sub.xCl.sub.y) 230 is
prevented from depositing on the sidewall of chamber 201.
[0171] In the above-described apparatus for the formation of a
metal film, since chlorine gas (Cl.sub.2 gas) is used as raw
material gas 205 and a hydrogen-containing gas is used as reducing
gas 213, a marked reduction in cost is achieved. Moreover, since
the reduction reaction can be accelerated independently, the amount
of impurities (e.g., chlorine) remaining in thin Cu film 233 can be
minimized to form a thin Cu film 233 of high quality. Furthermore,
since atomic reducing gas 251 comprising atomic hydrogen can be fed
simply by use of reducing gas nozzle 215 which permits a relatively
flexible arrangement, a film having a large area (e.g., 50
mm.times.50 mm) can be stably formed.
[0172] In addition, since the sidewall of chamber 201 is heated to
a predetermined temperature by heater 228, precursor
(Cu.sub.xCl.sub.y) 230 adhering to the sidewall of chamber 201 will
readily be vaporized because of its raised vapor pressure. Thus,
precursor (Cu.sub.xCl.sub.y) 230 is prevented from depositing on
the sidewall of chamber 201. Consequently, the necessity of
cleaning the inside of chamber 201 periodically can be eliminated
to cause an improvement in raw material efficiency and a reduction
in running cost.
[0173] Now, an apparatus and method for the formation of a metal
film in accordance with a tenth embodiment of the present invention
is described with reference to FIG. 14. FIG. 14 is a schematic side
view of the apparatus for the formation of a metal film in
accordance with the tenth embodiment of the present invention. The
same components as those shown in FIG. 13 are designated by the
same reference numerals and the duplicate explanation thereof is
omitted.
[0174] When compared with the apparatus for the formation of a
metal film as illustrated in FIG. 13, the apparatus for the
formation of a metal film in accordance with the tenth embodiment
as illustrated in FIG. 14 does not include the chamber heating
means comprising filament type heater 228 and power supply 229, but
includes a discharge plate heating means for heating discharge
plate 209. Specifically, discharge plate (or metallic plate) 209
made of Copper (Cu) is provided at the bottom of inlet vessel 206
through the medium of an insulating member 241. An auxiliary nozzle
242 for feeding a rare gas comprising He gas is connected to the
sidewall of inlet vessel 206. Thus, He gas is fed into inlet vessel
206 together with raw material gas 205 comprising chlorine gas
(Cl.sub.2 gas). Cl.sub.2 gas and He gas are fed into inlet vessel
206 in a ratio of approximately 1:1. A biasing power supply 243 is
connected to discharge plate 209, so that a direct-current voltage
is applied to discharge plate 209 by biasing power supply 243.
[0175] In the above-described apparatus for the formation of a
metal film, when electromagnetic waves are radiated into inlet
vessel 206 by first plasma antenna 222 of first plasma generating
means 202, the Cl.sub.2 gas and He gas within inlet vessel 206 are
ionized to generate Cl.sub.2--He gas plasma 244. This Cl.sub.2--He
gas plasma 244 causes He ions to collide with discharge plate 209
to which a bias voltage is applied. Thus, discharge plate 209 is
uniformly heated. As the means for heating discharge plate 209, a
heater or other means for heating discharge plate 209 directly may
also be used in place of the means based on the collision of He
ions.
[0176] The heating temperature of discharge plate 209 is for
example, in the range of 200 to 800.degree. C. and preferably
600.degree. C. It is preferable that the lower limit of the heating
temperature is a temperature at which precursor (Cu.sub.xCl.sub.y)
230 passing through discharge orifices 210 becomes a monomeric
compound rather than a polymeric one. When discharge plate 209 is
heated to 600.degree. C., precursor 230 tends to be monomeric CuCl
and this facilitates the reduction reaction which will be described
later. The upper limit of the heating temperature depends on the
material of discharge plate 209. In the case of discharge plate 209
made of copper (Cu), the upper limit is 800.degree. C. If the
heating temperature exceeds 800.degree. C., discharge plate 209
cannot be used because of its softening. Discharge plate 209 can be
adjusted to a desired temperature by controlling the voltage
applied to discharge plate 209.
[0177] When Cl.sub.2--He gas plasma 244 is generated within inlet
vessel 206, the Cl.sub.2 gas plasma causes an etching reaction of
the heated discharge plate 209 made of Cu, so that a monomeric
precursor (CuCl) 230 tends to be produced. The resulting precursor
(CuCl) 230 is discharged downward through discharge orifices 210 of
discharge plate 209. Immediately before precursor (CuCl) 230
discharged downward through discharge orifices 210 arrives at
substrate 212, it passes through atomic reducing gas 251. Thus,
chlorine is removed from precursor (CuCl) 230 by a reduction
reaction with atomic hydrogen. The resulting Cu ions are directed
onto substrate 212 to form a thin Cu film 233 on the surface of
substrate 212.
[0178] Since precursor 230 discharged downward comprises monomeric
CuCl, it can readily be reduced by atomic hydrogen. Thus, chlorine
is removed therefrom by reduction in a short period of time.
Consequently, the resulting Cu ions are directed onto substrate 212
to form a thin Cu film 233 on the surface of substrate 212 in a
short period of time. That is, since discharge plate 209 is
uniformly heated to a desired temperature by the collision of He
ions, a monomeric precursor (CuCl) 230 which can readily be reduced
is produced. This makes it possible to remove chlorine by reduction
in a short period of time and thereby improve the rate of film
growth.
[0179] Now, an apparatus and method for the formation of a metal
film in accordance with an eleventh embodiment of the present
invention is described with reference to FIG. 15. FIG. 15 is a
schematic side view of the apparatus for the formation of a metal
film in accordance with the eleventh embodiment of the present
invention. The same components as those shown in FIGS. 13 and 14
are designated by the same reference numerals and the duplicate
explanation thereof is omitted.
[0180] When compared with the apparatus for the formation of a
metal film is illustrated in FIG. 14, the apparatus for the
formation of a metal film in accordance with the eleventh
embodiment as illustrated in FIG. 15 includes a chamber heating
means comprising a filament type heater 228 and a power supply 229.
That is, this apparatus is equipped with both the chamber heating
means and the discharge plate heating means.
[0181] Thus, since the sidewall of chamber 201 is heated to a
predetermined temperature (e.g., 200.degree. C.) by heater 228,
precursor (CuCl) 230 adhering to the sidewall of chamber 201 will
readily be vaporized because of its raised vapor pressure.
Consequently, precursor (CuCl) 230 is prevented from depositing on
the sidewall of chamber 201. Moreover, since precursor 230
discharged downward comprises monomeric CuCl, it can readily be
reduced by atomic hydrogen. Thus, chlorine is removed therefrom by
reduction in a short period of time. Consequently, the resulting Cu
ions are directed onto substrate 212 to form a thin Cu film 233 on
the surface of substrate 212 in a short period of time.
[0182] Accordingly, since the sidewall of chamber 201 is heated to
a predetermined temperature by heater 228, precursor (CuCl) 230
adhering to the sidewall of chamber 201 will readily be vaporized
because of its raised vapor pressure. Thus, precursor (CuCl) 230 is
prevented from depositing on the sidewall of chamber 201.
Consequently, the necessity of cleaning the inside of chamber 201
periodically can be eliminated to cause an improvement in raw
material efficiency and a reduction in running cost. Moreover,
since discharge plate 209 is uniformly heated to a desired
temperature by the collision of He ions, a monomeric precursor
(CuCl) 230 which can readily be reduced is produced. This makes it
possible to remove chlorine by reduction in a short period of time
and thereby improve the rate of film growth.
[0183] Now, an apparatus and method for the formation of a metal
film in accordance with a twelfth embodiment of the present
invention is described with reference to FIG. 16. FIG. 16 is a
schematic side view of the apparatus for the formation of a metal
film in accordance with the twelfth embodiment of the present
invention. The same components as those shown in FIG. 13 are
designated by the same reference numerals and the duplicate
explanation thereof is omitted.
[0184] When compared with the apparatus for the formation of a
metal film as illustrated in FIG. 13, the apparatus for the
formation of a metal film in accordance with the twelfth embodiment
as illustrated in FIG. 16 is characterized in that a precursor
(Cu.sub.xCl.sub.y) 230 is injected into chamber 201 from a nozzle
208 of a raw material gas heating means 261, instead of generating
Cl.sub.2 gas plasma 231 within inlet vessel 206 to produce
precursor (Cu.sub.xCl.sub.y) 230. Raw material gas heating means
261 consists of a flow controller 207, a nozzle 208 attached
thereto, and a copper filament 262 comprising several turns of
copper wire and disposed within nozzle 208. The ends of copper
filament 262 are connected to a direct-current power supply 263.
Copper filament 262 is heated to 300-600.degree. C. by
direct-current power supply 263.
[0185] In the above-described apparatus for the formation of a
metal film, a raw material gas comprising Cl.sub.2 gas is passed
through flow controller 207 in order to control its flow rate, and
then fed into nozzle 208. Since nozzle 208 is provided therein with
copper filament 262 which has been heated to 300-600.degree. C. by
direct-current power supply 263, the contact of Cl.sub.2 gas with
the heated copper filament 262 produces a precursor
(Cu.sub.xCl.sub.y) 230. When this precursor (Cu.sub.xCl.sub.y) 230
is introduced into chamber 201 through nozzle 208, precursor
(Cu.sub.xCl.sub.y) 230 moves downward.
[0186] Immediately before precursor (Cu.sub.xCl.sub.y) 230 arrives
at substrate 212, a reducing gas 213 comprising H.sub.2 gas is
passed through reducing gas flow controllers 214 in order to
control its flow rate, and tungsten filament 253 is heated to
1,800.degree. C. by means of direct-current power supply 254. As a
result of the hearing of tungsten filament 253, an atomic reducing
gas 251 (atomic hydrogen) is produced and injected into chamber 201
through reducing gas inlet nozzle 215. Consequently, precursor
(Cu.sub.xl.sub.y) 230 discharged downward through discharge
orifices 210 passes through atomic reducing gas 251 immediately
before arriving at substrate 212. Thus, chlorine is removed from
precursor (Cu.sub.xCl.sub.y) 230 by a reduction reaction with
atomic hydrogen. The resulting Cu ions are directed onto substrate
212 to form a thin Cu film 233 on the surface of substrate 212.
[0187] Since the sidewall of chamber 201 is heated to a
predetermined temperature (e.g., 200.degree. C.) by heater 228 as
described previously, precursor (Cu.sub.xCl.sub.y) 230 adhering to
the sidewall of chamber 201 will readily be vaporized because of
its raised vapor pressure. Consequently, precursor
(Cu.sub.xCl.sub.y) 230 is prevented from depositing on the sidewall
of chamber 201.
[0188] In the above-described apparatus for the formation of a
metal film, since precursor (Cu.sub.xCl.sub.y) 230 can be fed
simply by use of nozzle 208 which permits a relatively flexible
arrangement, and atomic hydrogen can be fed simply by use of
reducing gas nozzle 215 which permits a relatively flexible
arrangement, a film having a large area (e.g., 100 mm.times.100 mm)
can be very stably formed.
[0189] Moreover, since the sidewall of chamber 201 is heated to a
predetermined temperature by heater 228, precursor (CuCl) 230
adhering to the sidewall of chamber 201 will readily be vaporized
because of its raised vapor pressure. Thus, precursor (CuCl) 230 is
prevented from depositing on the sidewall of chamber 201.
Consequently, the necessity of cleaning the inside of chamber 201
periodically can be eliminated to cause an improvement in raw
material efficiency and a reduction in running cost.
[0190] FIG. 17 is a schematic sectional view of an apparatus for
the vapor phase growth of a thin copper film in accordance with a
thirteenth embodiment of the present invention, and FIG. 18 is a
plan view of a discharge plate made of copper and incorporated into
the vapor phase growth apparatus of FIG. 17.
[0191] Within a reaction vessel 302 formed into the shape of a box
and provided with an exhaust tube 301 at the bottom, a flat plate
type heater 303 is disposed and a substrate to be treated is placed
thereon. An evacuation means (not shown), such as a vacuum pump, is
connected to the other end of the aforesaid exhaust tube 301. An
inlet vessel 306 in the form of a closed-end cylinder, which has a
copper discharge plate 305 having a plurality of discharge orifices
304 bored therethrough at the bottom, is suspended in the upper
part of the aforesaid reaction vessel 302. The aforesaid copper
discharge plate 305 is provided with a circulation pipe 307 serving
as a temperature control means for passing a heating medium (e.g.,
heated air) or a cooling medium (e.g., cooled air) therethrough. As
illustrated in FIG. 18, this circulation pipe 307 is built in the
aforesaid copper discharge plate 305 so that it lies in parallel
with the surfaces of discharge plate 305 and runs in a serpentine
manner.
[0192] A raw material gas feed pipe 308 for feeding chlorine or
hydrogen chloride extends from the outside through the sidewall of
the aforesaid reaction vessel 302 and the sidewall of the aforesaid
inlet vessel 306, and is inserted into the interior of the
aforesaid inlet vessel 306. A flow controller 309 is installed in a
portion of the aforesaid raw material gas feed pipe 308 which is
located on the outside of the aforesaid reaction vessel 302. A
first plasma generator 310 is disposed on the top surface of the
aforesaid reaction vessel 302 to which the aforesaid inlet vessel
306 is attached. This first plasma generator 310 consists of an
insulating plate 311 disposed on the top surface of the aforesaid
reaction vessel 302 so as to cover the aforesaid inlet vessel 306,
a first plasma antenna 312 disposed on this insulating plate 311,
and a first plasma power supply 313 connected to this first plasma
antenna 312.
[0193] A water partial pressure gauge 315 having two sensing
elements 314a and 314b is disposed on the outside of the aforesaid
reaction vessel 302. One sensing elements 314a extends through the
sidewall of the aforesaid reaction vessel 302 and the sidewall of
the aforesaid inlet vessel 306, and is inserted into the interior
of the aforesaid inlet vessel 306. The other sensing elements 314b
extends through the sidewall of the aforesaid reaction vessel 302
and is inserted into the interior of the aforesaid reaction vessel
302. The aforesaid water partial pressure gauge 341 is used to
measure the partial pressure of water when the aforesaid reaction
vessel 302 and the aforesaid inlet vessel 306 are evacuated prior
to film formation. A hydrogen feed pipe 316 for feeding a reducing
gas (e.g., hydrogen) extends from the outside through the lower
sidewall of the reaction vessel 302 and is inserted into the
interior of the aforesaid reaction vessel 302. A flow controller
317 is installed in a portion of the aforesaid hydrogen feed pipe
316 which is located on the outside of the aforesaid reaction
vessel 302. A second plasma generator 318 is disposed at the bottom
of the aforesaid reaction vessel 302. This second plasma generator
318 consists of an insulating plate 319 disposed on the bottom
surface of the aforesaid reaction vessel 302, a second plasma
antenna 320 disposed on the underside of this insulating plate 319,
and a second plasma power supply 321 connected to the underside of
this second plasma antenna 320. A rotating magnetic field coil 322
is disposed around the lower sidewall of the aforesaid reaction
vessel 302 with a desired space left therebetween. This rotating
magnetic field coil 322 acts on the hydrogen plasma generated above
the aforesaid heater 303 of the aforesaid reaction vessel 302 as
will be described later so that the hydrogen plasma may be densely
distributed in the neighborhood of the surface of the substrate to
be treated which is placed on the aforesaid heater 303.
[0194] Now, the method for forming a thin copper film by using the
above-described apparatus for the vapor phase growth of a thin
copper film as illustrated in FIGS. 17 and 18 is described
below.
[0195] First of all, a substrate 323 to be treated is placed on the
flat plate type heater 303 of reaction vessel 302. An evacuation
means (not shown) is operated to remove the gas (air) within the
aforesaid reaction vessel 302 and inlet vessel 306 through exhaust
tube 301 until a predetermined degree of vacuum is reached.
[0196] In this evacuation step, the partial pressures of water
within the aforesaid reaction vessel 302 and inlet vessel 306 are
measured by means of water partial pressure gauge 315 to confirm
that the partial pressures of water remain constant. After the
partial pressures of water have been confirmed, hydrogen is fed
into the aforesaid reaction vessel 302 through hydrogen feed pipe
316. The flow rate of this hydrogen is controlled by means of flow
controller 317 installed in the aforesaid hydrogen feed pipe 316.
The second plasma power supply 321 of second plasma generator 318
is operated to apply, for example, high-frequency electric power to
the aforesaid second plasma antenna 320 and thereby generate
hydrogen plasma 324 above and near the aforesaid substrate 323 to
be treated. Under the action of a rotating magnetic field created
by rotating magnetic field coil 322 disposed on the outside of the
aforesaid reaction vessel 302, the aforesaid hydrogen plasma 324 is
densely distributed in the neighborhood of the surface of the
aforesaid substrate 323 to be treated.
[0197] Then, a raw material gas comprising, for example, chlorine
(Cl.sub.2) is fed into the aforesaid inlet vessel 306 through raw
material gas feed pipe 308. The flow rate of this chlorine is
controlled by means of flow controller 309 installed in the
aforesaid raw material gas feed pipe 308. A heating medium (e.g.,
heated air) heated to a predetermined temperature is supplied to
and circulated through the circulation pipe 307 of copper discharge
plate 305. Thus, copper discharge plate 305 is heated to a
predetermined temperature. After heating copper discharge plate
305, the first plasma power supply 313 of first plasma generator
310 is operated to apply, for example, high-frequency electric
power to the aforesaid first plasma antenna 312 and thereby
generate chlorine plasma 325 within the aforesaid inlet vessel 306.
If the temperature of the aforesaid discharge plate 305 is
excessively raised with the generation of chlorine plasma 325, the
aforesaid discharge plate 305 may be adjusted to a desired
temperature by supplying a cooling medium to the aforesaid
circulation pipe 307 in place of the aforesaid heating medium.
[0198] As a result of the above-described generation of chlorine
plasma 324, activated chlorine in this plasma 324 reacts with
copper discharge plate 305 which has been heated to a predetermined
temperature by supplying and circulating a heating medium through
the aforesaid circulation pipe 307. Thus, a precursor
(Cu.sub.xCl.sub.y) comprising copper chloride is produced. As shown
by arrows in FIG. 17, the resulting precursor (Cu.sub.xCl.sub.y) is
discharged into the aforesaid reaction vessel 302 through the
plurality of discharge orifices 304 of the aforesaid discharge
plate 305. Immediately before the discharged precursor arrives at
substrate 323 to be treated which is placed on flat plate type
heater 303, it passes through the aforesaid hydrogen plasma 324 and
undergoes a reduction reaction with atomic hydrogen in this
hydrogen plasma 324. Consequently, copper produced by the reduction
reaction of the precursor. (Cu.sub.xCl.sub.y) with atomic hydrogen
grows on the aforesaid substrate 323 to be treated, resulting in
the formation of a thin copper film.
[0199] Thus, according to the thirteenth embodiment, an inexpensive
copper chloride precursor (Cu.sub.xCl.sub.y) useful as a raw
material for the vapor phase growth of copper can be produced by
feeding inexpensive chlorine into inlet vessel 306 having copper
discharge plate 305 at the bottom through raw material feed pipe
308, generating chlorine plasma 325 within the aforesaid inlet
vessel 306 by means of first plasma generator 310, and reacting
activated chlorine in this plasma 325 with the aforesaid copper
discharge plate 305. Moreover, since the reaction of activated
chlorine in plasma 325 with the aforesaid copper discharge plate
305 can be accelerated by supplying and circulating a heating
medium through circulation pipe 307 built in the aforesaid copper
discharge plate 305 and thus heating the aforesaid copper discharge
plate 305 to a predetermined temperature, the amount of precursor
(Cu.sub.xCl.sub.y) produced can be increased.
[0200] The precursor so produced is discharged into reaction vessel
302 through the plurality of discharge orifices 304 of the
aforesaid discharge plate 305, and subjected to a reduction
reaction with atomic hydrogen while it passes through hydrogen
plasma 324 previously generated within the aforesaid reaction
vessel 302.
[0201] Thus, a thin copper film can be rapidly formed on the
aforesaid substrate 323 to be treated, because copper can grow at a
relatively higher rate than in thermal decomposition processes.
[0202] Moreover, copper discharge plate 305 begins to react with
activated chlorine in the aforesaid chlorine plasma 325 when copper
discharge plate 305 is heated to a certain temperature by supplying
and circulating a heating medium through circulation pipe 307 built
in copper discharge plate 305. Consequently, the pressure of the
precursor discharged through the plurality of discharge orifices
304 of the aforesaid copper discharge plate (i.e., the discharge
pressure) can be stabilized.
[0203] Moreover, the same type of precursor (Cu.sub.xCl.sub.y) is
produced. As a result, the rate of copper film growth on the
aforesaid substrate 323 to be treated can be stabilized, so that a
thin copper film having a desired thickness can be reproducibly
formed on the aforesaid substrate 323 to be treated.
[0204] Furthermore, not only the aforesaid precursor
(Cu.sub.xCl.sub.y) undergoes a reduction reaction with atomic
hydrogen while it passes through hydrogen plasma 324, and causes
the vapor phase growth of copper on the surface of the aforesaid
substrate 323 to be treated, but also atomic hydrogen in hydrogen
plasma 324 exerts a reducing action on the growing copper film.
Consequently, a thin copper film containing little residual can be
formed.
[0205] In the above-described thirteenth embodiment, a circulation
pipe for passing a heating medium or cooling medium therethrough is
used as the temperature control means for the aforesaid copper
discharge plate. However, the present invention is not limited
thereto, but the aforesaid copper discharge plate may be provided
with a combination of a heater and a circulation pipe for a cooling
medium.
[0206] Although chlorine is used as the raw material gas in the
above-described thirteenth embodiment, a copper chloride precursor
(Cu.sub.xCl.sub.y) can also be produced by using hydrogen
chloride.
[0207] Although atomic hydrogen is produced by converting hydrogen
into a plasma in the above-described thirteenth embodiment, atomic
hydrogen may also be produced by installing a heater (e.g., a
tungsten filament) for heating hydrogen fed into the aforesaid
reaction vessel.
[0208] FIG. 19 is a schematic sectional view of an apparatus for
the vapor phase growth of a thin copper film in accordance with a
fourteenth embodiment of the present invention, FIG. 20(A) is a
longitudinal sectional view of a spiral tube incorporated into the
vapor phase growth apparatus of FIG. 19, FIG. 20(B) is a transverse
sectional view of this spiral tube, FIG. 21(A) is a longitudinal
sectional view of another type of spiral tube incorporated into the
vapor phase growth apparatus of FIG. 19, and FIG. 21(B) is a
transverse sectional view of this spiral tube.
[0209] Within a reaction vessel 332 formed into the shape of a box
and provided with an exhaust tube 331 at the bottom, a flat plate
type heater 333 is disposed and a substrate to be treated is placed
thereon. An evacuation means (not shown), such as a vacuum pump, is
connected to the other end of the aforesaid exhaust tube 331.
[0210] A raw material gas feed pipe 334 for feeding chlorine or
hydrogen chloride extends from the outside through the sidewall of
the aforesaid reaction vessel 332 and is inserted into the upper
part of the aforesaid reaction vessel 332. A flow controller 335 is
installed in a portion of the aforesaid raw material gas feed pipe
334 which is located on the outside of the aforesaid reaction
vessel 332. The aforesaid reaction vessel 332 includes a spiral
tube 336 having a raw material gas flow passage whose inner surface
is made of copper, and equipped with a heating element. Its upper
end is connected to the end of the aforesaid raw material gas feed
pipe 334 which is located on the inside of the aforesaid reaction
vessel 332. This spiral tube 336 has, for example, a dual tubular
structure consisting of an outer tube 337 and an inner copper tube
338 inserted into this outer tube 337 and connected to the
aforesaid raw material gas feed pipe 334, as illustrated in FIG.
20. The aforesaid raw material gas is made to flow through the
aforesaid inner copper tube 338, and a heating medium (e.g., heated
air) is made to flow through the annular space between the
aforesaid outer tube 337 and the aforesaid inner copper tube 338. A
heating medium feed pipe (not shown), which extends through a wall
of the aforesaid reaction vessel 332, is connected to a portion of
outer tube 337 of spiral tube 336 which is located in the
neighborhood of its joint with the aforesaid raw material gas feed
pipe 334, and used to feed a heating medium into the annular space
between the aforesaid outer tube 337 and the aforesaid inner copper
tube 338. Moreover, a heating medium discharge pipe (not shown),
which extends through a wall of the aforesaid reaction vessel 332,
is connected to a portion of outer tube 337 which is located in the
neighborhood of the lower end of the aforesaid spiral tube 336, and
used to discharge the heating medium fed into the aforesaid annular
space to the outside.
[0211] A precursor discharge member 339 is disposed within the
aforesaid reaction vessel 332 in such a way that the aforesaid
precursor discharge member 339 lies under the aforesaid spiral tube
336 and its upper part is connected to the aforesaid spiral tube
336.
[0212] A water partial pressure gauge 341 having two sensing
elements 340a and 340b is disposed on the outside of the aforesaid
reaction vessel 332. One sensing elements 340a extends through the
sidewall of the aforesaid reaction vessel 332 and the outer tube
337 and inner copper tube 338 of the aforesaid spiral tube 336, and
is inserted into the interior of the aforesaid inner copper tube
338. The other sensing elements 340b extends through the sidewall
of the aforesaid reaction vessel 332 and is inserted into the
interior of the aforesaid reaction vessel 332. The aforesaid water
partial pressure gauge 341 is used to measure the partial pressure
of water when the aforesaid reaction vessel 332 and the inner
copper tube 338 of the aforesaid spiral tube 336 are evacuated
prior to film formation.
[0213] A hydrogen feed pipe 342 for feeding a reducing gas (e.g.,
hydrogen) extends from the outside through the lower sidewall of
the aforesaid reaction vessel 332 and is inserted into the interior
of the aforesaid reaction vessel 332. A flow controller 343 is
installed in a portion of the aforesaid hydrogen feed pipe 342
which is located on the outside of the aforesaid reaction vessel
332. A plasma generator 344 is disposed at the bottom of the
aforesaid reaction vessel 332. This plasma generator 344 consists
of an insulating plate 345 disposed on the bottom surface of the
aforesaid reaction vessel 332, a plasma antenna 346 disposed on the
underside of this insulating plate 345, and a plasma power supply
347 connected to the underside of this plasma antenna 346. A
rotating magnetic field coil 348 is disposed around the lower
sidewall of the aforesaid reaction vessel 332 with a desired space
left therebetween. This rotating magnetic field coil 348 acts on
the hydrogen plasma generated above the aforesaid heater 333 of the
aforesaid reaction vessel 332 as will be described later so that
the hydrogen plasma may be densely distributed in the neighborhood
of the surface of the substrate to be treated which is placed on
the aforesaid heater 333.
[0214] Now, the method for forming a thin copper film by using the
above-described apparatus for the vapor phase growth of a thin
copper film as illustrated in FIGS. 19 and 20 is described
below.
[0215] First of all, a substrate 349 to be treated is placed on the
flat plate type heater 333 of reaction vessel 332. An evacuation
means (not shown) is operated to remove the gas (air) within the
aforesaid reaction vessel 332 and the inner copper tube 338 of
spiral tube 336 through exhaust tube 331 until a predetermined
degree of vacuum is reached.
[0216] In this evacuation step, the partial pressures of water
within the aforesaid reaction vessel 332 and the inner copper tube
338 of spiral tube 336 are measured by means of water partial
pressure gauge 341 to confirm that the partial pressures of water
remain constant. After the partial pressures of water have been
confirmed, hydrogen is fed into the aforesaid reaction vessel 332
through hydrogen feed pipe 342. The flow rate of this hydrogen is
controlled by means of flow controller 343 installed in the
aforesaid hydrogen feed pipe 342. The plasma power supply 347 of
plasma generator 344 is operated to apply, for example,
high-frequency electric power to the aforesaid plasma antenna 346
and thereby generate hydrogen plasma 350 above and near the
aforesaid substrate 349 to be treated. Under the action of a
rotating magnetic field created by rotating magnetic field coil 348
disposed on the outside of the aforesaid reaction vessel 332, the
aforesaid hydrogen plasma 350 is densely distributed in the
neighborhood of the surface of the aforesaid substrate 349 to be
treated.
[0217] Then, a raw material gas comprising, for example, chlorine
(Cl.sub.2) is fed into the inner copper tube 338 of the aforesaid
spiral tube 336 through raw material gas feed pipe 334. The flow
rate of this chlorine is controlled by means of flow controller 335
installed in the aforesaid raw material gas feed pipe 334. A
heating medium (e.g., heated air) heated to a predetermined
temperature is supplied from the outside of the aforesaid reaction
vessel 332 through a heating medium feed pipe (not shown) to the
annular space between the outer tube 337 and inner copper tube 338
of the aforesaid spiral tube 336. This heating medium is discharged
to the outside through a heating medium discharge pipe (not shown).
Thus, the inner copper tube 338 of the aforesaid spiral tube 336 is
heated to a predetermined temperature, so that the aforesaid inner
copper tube 338 reacts with the chlorine (Cl.sub.2) flowing
therethrough to produce a precursor (Cu.sub.xCl.sub.y) comprising
copper chloride.
[0218] As shown by arrows in FIG. 19, the resulting precursor
(Cu.sub.xCl.sub.y) is discharged into the aforesaid reaction vessel
332 from precursor discharge member 339. Immediately before the
discharged precursor arrives at substrate 349 to be treated which
is placed on flat plate type heater 333, it passes through the
aforesaid hydrogen plasma 350 and undergoes a reduction reaction
with atomic hydrogen in this hydrogen plasma 350. Consequently,
copper produced by the reduction reaction of the precursor
(Cu.sub.xCl.sub.y) with atomic hydrogen grows on the aforesaid
substrate 349 to be treated, resulting in the formation of a thin
copper film.
[0219] Thus, according to the fourteenth embodiment, an inexpensive
copper chloride precursor (Cu.sub.xCl.sub.y) useful as a raw
material for the vapor phase growth of copper can be produced by
feeding inexpensive chlorine into the inner copper tube 338 of
spiral tube 336, passing a heating medium through the annular space
between the outer tube 337 and inner copper tube 338 of the
aforesaid spiral tube 336 to heat the aforesaid inner copper tube
338, and thus reacting chlorine with the aforesaid inner copper
tube 338.
[0220] The precursor so produced is discharged into reaction vessel
332 from precursor discharge member 339, and subjected to a
reduction reaction with atomic hydrogen while it passes through
hydrogen plasma 350 previously generated within the aforesaid
reaction vessel 332. Thus, a thin copper film can be rapidly formed
on the aforesaid substrate 349 to be treated, because copper can
grow at a relatively higher rate than in thermal decomposition
processes.
[0221] Moreover, the aforesaid inner copper tube 338 begins to
react with chlorine flowing through this inner copper tube 338 when
inner copper tube 338 is heated to a certain temperature by passing
a heating medium through the annular space between the outer tube
337 and inner copper tube 338 of the aforesaid spiral tube 336.
Consequently, the pressure of the precursor discharged from the
aforesaid precursor discharge member 339 (i.e., the discharge
pressure) can be stabilized. Moreover, the same type of precursor
(Cu.sub.xCl.sub.y) is produced. As a result, the rate of copper
film growth on the aforesaid substrate 349 to be treated can be
stabilized, so that a thin copper film having a desired thickness
can be reproducibly formed on the aforesaid substrate 349.
[0222] Furthermore, not only the aforesaid precursor
(Cu.sub.xCl.sub.y) undergoes a reduction reaction with atomic
hydrogen while it passes through hydrogen plasma 350, and causes
the vapor phase growth of copper on the surface of the aforesaid
substrate 349 to be treated, but also atomic hydrogen in hydrogen
plasma 350 exerts a reducing action on the growing copper film.
Consequently, a thin copper film containing little residual
impurity (e.g., chlorine) and hence having a good film quality can
be formed.
[0223] In the above-described fourteenth embodiment, the spiral
tube has a dual tubular structure and the aforesaid inner copper
tube is heated by supplying a heating medium to the annular space
between the outer tube and inner copper tube of the aforesaid
spiral tube. However, the present invention is not limited to the
above-described structure. For example, as illustrated in FIG. 21,
spiral tube 336 may have a structure consisting of a copper tube
351 and a tubular heater 353 disposed around copper tube 351 with a
tubular insulator 352 interposed therebetween. Thus, the aforesaid
copper tube 351 can be heated to a predetermined temperature by the
aforesaid tubular heater 353.
[0224] Although chlorine is used as the raw material gas in the
above-described fourteenth embodiment, a copper chloride precursor
(Cu.sub.xCl.sub.y) can also be produced by using hydrogen
chloride.
[0225] Although atomic hydrogen is produced by converting hydrogen
into a plasma in the above-described fourteenth embodiment, atomic
hydrogen may also be produced by installing a heater or other means
for heating hydrogen fed into the aforesaid reaction vessel.
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