U.S. patent application number 10/910269 was filed with the patent office on 2007-05-17 for heated gas box for pecvd applications.
This patent application is currently assigned to APPLIED MATERIALS, INC.. Invention is credited to Nancy Fung, Brian Hopper, Eller Juco, Andrzej Kaszuba, Thomas Nowak, Soovo Sen, Inna Shmurun.
Application Number | 20070107660 10/910269 |
Document ID | / |
Family ID | 35448162 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070107660 |
Kind Code |
A9 |
Sen; Soovo ; et al. |
May 17, 2007 |
Heated gas box for PECVD applications
Abstract
A method and apparatus for a chamber for chemical vapor
deposition on a substrate in a processing region comprising a gas
box having a heated lid comprising a gas inlet passage, and a face
plate connected to the heated lid positioned to conduct gas from
the heated gas box to a substrate processing region. Also, a method
for providing heat to a chemical vapor deposition chamber
comprising supplying heat to a lid of a gas box, and heating a face
plate connected to the gas box by heat transfer from the lid.
Inventors: |
Sen; Soovo; (Sunnyvale,
CA) ; Shmurun; Inna; (Foster City, CA) ;
Nowak; Thomas; (Cupertino, CA) ; Fung; Nancy;
(Sunnyvale, CA) ; Hopper; Brian; (Campbell,
CA) ; Kaszuba; Andrzej; (San Jose, CA) ; Juco;
Eller; (San Jose, CA) |
Correspondence
Address: |
PATTERSON & SHERIDAN, LLP
3040 POST OAK BOULEVARD, SUITE 1500
HOUSTON
TX
77056
US
|
Assignee: |
APPLIED MATERIALS, INC.
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20060027165 A1 |
February 9, 2006 |
|
|
Family ID: |
35448162 |
Appl. No.: |
10/910269 |
Filed: |
August 3, 2004 |
Current U.S.
Class: |
118/715 |
Current CPC
Class: |
H01L 21/67103
20130101 |
Class at
Publication: |
118/715 |
International
Class: |
C23C 16/00 20060101
C23C016/00 |
Claims
1. A chamber for chemical vapor deposition on a substrate in a
processing region, comprising: a gas box having a heated lid
comprising a gas inlet passage; and a face plate connected to the
heated lid and positioned to conduct gas from the heated gas box to
a substrate processing region.
2. The chamber of claim 1, wherein a heating element is embedded in
an insert that contacts the heated lid and the face plate.
3. The chamber of claim 1, wherein a heating element is embedded in
an insert located along an upper surface of the heated lid.
4. The chamber of claim 2, wherein the insert is a silicon rubber
insert.
5. The chamber of claim 4, wherein the silicon rubber insert is
wire wound.
6. A method for providing heat to a chemical vapor deposition
chamber, comprising: supplying heat to a lid of a gas box; and
heating a face plate connected to the gas box by heat transfer from
the lid.
7. The method of claim 6, wherein a heating element is embedded in
an insert positioned between the lid and the faceplate.
8. The method of claim 7, wherein the heating element is embedded
in a silicon rubber insert.
9. The method of claim 8, wherein the silicon rubber insert is wire
wound.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] Embodiments of the present invention generally relate to a
method and apparatus to provide chemical vapor deposition (CVD) of
a film in a microprocessor processing chamber and to provide a
mechanism for improved cleaning of the chamber.
[0003] 2. Description of the Related Aart
[0004] Chemical vapor deposition (CVD) chambers may be used to
deposit materials such as oxides onto substrates used in the
fabrication of integrated circuits and semiconductor devices. In a
CVD chamber, a gas distribution plate is commonly used to uniformly
distribute gases into a chamber. Such a uniform gas distribution is
necessary to achieve uniform deposition of the material on the
surface of a substrate located within the chamber. The gas
distribution plate generally receives deposition gases from a
mixing region, also known as a gas box, above the gas distribution
plate. A gas inlet passage into the gas box is typically
water-cooled to a temperature of approximately under 100.degree. C.
A heater is generally disposed in a substrate support member
beneath the gas distribution plate. The heater is typically heated
to a temperature of approximately between 100 and 600.degree. C.
Consequently, the temperature of the gas distribution plate is
somewhere between the temperature of the gas inlet passage and the
temperature of the heater. However, because the gas distribution
plate is connected to the gas inlet passage, the temperature of the
gas distribution plate is generally closer to the temperature of
the gas inlet passage than the temperature of the heater.
[0005] FIG. 1 is a schematic view of a chamber that has two
processing regions, 618, 620 connected to two remote plasma sources
800. One remote plasma source 800 is connected to processing region
618, and the other remote plasma source 800 is connected to
processing region 620. A heater pedestal 628 is movably disposed in
each processing region 618, 620 by a stem 626 which extends through
the bottom of the chamber body 612 where it is connected to a drive
system 603. Each of the processing regions 618, 620 includes a gas
distribution assembly comprising a gas box 642 disposed through the
chamber lid 604 to deliver gases into the processing regions 618,
620 through blocker plates 602. The gas distribution assembly 608
of each processing region also includes a gas inlet passage 640
which delivers gas into a gas box 642. A cooling channel 652 is
formed in a base plate 648 of each gas distribution assembly 608 to
cool the plate during operation. An inlet 655 delivers a coolant
fluid, such as water, into the cooling channels 652 which are
connected to each other by coolant line 657. The cooling fluid
exits the channel through a coolant outlet 659. Alternatively, the
cooling fluid is circulated through the manifold.
[0006] For CVD films such as carbon doped silicon oxide, oxygen
doped silicon carbide, silicon oxide, amorphous carbon, and silicon
nitride, the deposition rate is inversely proportional to
temperature. As a result of the low temperature of the gas
distribution plate in comparison to the temperature of the
substrate heater, a film is often deposited on the gas distribution
plate during processing, which leads to a longer chamber cleaning
period and an increase in clean gas consumption. Another result of
the low temperature of the gas distribution plate is uneven
distribution of chemicals across the surface of the substrate which
can lead to non-uniform film properties across the wafer.
[0007] The deposition process also typically results in deposition
of some materials on the walls and components of the deposition
chamber. As the materials are distributed through the gas
distribution plate during processing, deposits are often formed on
the gas distribution plate which may clog the holes of the plate or
flake off in particles that rain down on the substrate. This
reduces the uniformity of deposition on the substrate and
contaminates the substrate. Consequently, it is necessary to clean
the interior of the deposition chamber on a regular basis.
[0008] Several methods of cleaning the deposition chamber
components including the gas distribution plate have been
developed. For example, a remote plasma cleaning procedure may be
employed. A high density plasma source such as a microwave plasma
system, toroidal plasma generator, or similar device may be
employed to generate a remote plasma. Dissociated species from the
remote plasma are then transported to the deposition chamber where
the species react with and etch away the undesired deposits. It is
also common to remove the deposits on the interior of chamber walls
with an in situ chamber clean operation. Common chamber cleaning
techniques include the use of an etchant gas such as fluorine or
oxygen to remove the deposited material from the chamber walls and
other areas. The etchant gas is introduced into the chamber and
plasma is formed so that the etchant gas reacts with and removes
the deposited material from the chamber walls. Also, heat may be
supplied to the chamber by heating elements or heat exchange fluid
embedded in the substrate support to facilitate cleaning or other
chamber processes.
[0009] Conventional chamber cleaning methods, however, still
require a considerable amount of time. The longer it takes to clean
the chamber, the lower the number of substrates that can be
processed in a given time and the more gas that is consumed to
clean the chamber.
[0010] Therefore, a need exists for an improved method for heating
and distributing gases into the processing region of a deposition
chamber and for cleaning a deposition chamber.
SUMMARY OF THE INVENTION
[0011] The present invention generally provides a chamber for
chemical vapor deposition on a substrate in a processing region,
comprising a heated gas box having a gas inlet passage and a face
plate positioned to conduct gas from the heated gas box to a
substrate processing region. The invention also provides a method
for providing heat to a chemical vapor deposition chamber,
comprising supplying heat to a substrate support and to a gas box
having a gas inlet passage. Heating the gas box instead of the face
plate reduces deposition within the gas box, reducing the chamber
clean time. This invention reduces the clean time for CVD processes
wherein the deposition rate is inversely proportional to
temperature such as processes for the deposition of carbon doped
silicon oxide, oxygen doped silicon carbide, silicon oxide, doped
amorphous carbon, and silicon nitride.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] So that the manner in which the above recited features of
the present invention can be understood in detail, a more
particular description of the invention, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this invention and are therefore not to be considered limiting of
its scope, for the invention may admit to other equally effective
embodiments.
[0013] FIG. 1 (prior art) is a schematic view of a deposition
chamber having a gas box that features cooling channels.
[0014] FIG. 2 is a schematic view of an embodiment of a gas
distribution assembly with a heated insert.
[0015] FIG. 3 is a partial sectional view of another embodiment of
a gas distribution assembly with an embedded heating element.
[0016] FIG. 4 is a partial sectional view of another embodiment of
a gas distribution assembly with a heating element placed on top of
the gas inlet passage.
[0017] FIG. 5 is a partial sectional view of another embodiment of
a gas distribution assembly with a heating element placed along the
side of the gas inlet passage.
DETAILED DESCRIPTION
[0018] The present invention provides a method and an apparatus for
chemical vapor deposition (CVD) of a film in a substrate processing
chamber and improved cleaning of the chamber. The deposition
chambers that may benefit from the apparatus and methods described
herein include chambers that may be used to deposit oxides, such as
carbon-doped silicon oxides, silicon containing films, and other
dielectric materials including advanced patterned films (APF). An
example of a deposition chamber is the Producer.RTM. Chamber,
available from Applied Materials, Inc. of Santa Clara, Calif. The
Producer.RTM. Chamber is a CVD chamber with two isolated processing
regions that may be used to deposit carbon-doped silicon oxides and
other materials. A chamber having two isolated processing regions
is described in U. S. Pat. No. 5,855,681, which is incorporated by
reference. The Producer.RTM. Chamber has a port to which remote
plasma sources may be attached. A Producer.RTM. Chamber with a
remote plasma source, model number 5707024-F, available from
Advanced Energy Industries, Inc. of Fort Collins, Colo., may be
used in embodiments of the methods described herein.
[0019] In the embodiments described herein, a remote plasma source
may be attached to a Producer.RTM. Chamber such that one remote
plasma source is connected to both isolated processing regions of
the Producer.RTM. Chamber. However, the processes described below
may also be performed by using two remote plasma sources connected,
for example, by a tee line, to each processing region of the
Producer.RTM. Chamber and by adjusting the flow rates accordingly.
The gas flow rates described below refer to flow rates experienced
by each of the isolated processing regions. The gas flow rates
experienced by the Producer.RTM. Chamber as a whole, that is, the
combination of flow rates of both of the isolated processing
regions, are approximately twice the gas flow rates experienced by
each of the isolated processing regions. While some examples of
embodiments are described as cleaning a single processing region of
a Producer Chamber that has two processing regions, the methods
described herein may be used to clean a processing region of a
chamber that has one or more processing regions.
[0020] FIG. 2 is a sectional view of an embodiment of the present
invention. This chamber 200 has a gas inlet passage 640 and a gas
box 642 that is heated by a heating element embedded in an annular
insert 201 along the upper portion of the gas box 642 and along the
upper surface of the faceplate 203. The heating element insert 201
is stabilized in place with a clamping plate 202. Insulation 205
may insulate the upper surface of the clamping plate. The heating
element insert 201 may be a silicone rubber heater such as a Watlow
heater with part number 168168500 available from the Watlow
Corporation of St. Louis, Mo. The insert 201 may also have wire
wound around its exterior surface. Thermocouples may be inserted
along the surface and embedded into the center of the insert 201.
The clamping plate 202 may act as an insulator. The clamping plate
202 may be made of an alloy or mixture of aluminum and stainless
steel. Alternatively, insulation may be supplied along the upper
surface of the insert 201 or the upper surface of the clamping
plate 202.
[0021] FIG. 3 is a sectional view of another alternative embodiment
of the chamber of FIG. 2. The chamber 300 has walls 302 of
faceplate 203 that engage the perimeter of the gas inlet passage
640, and contain channels 301 for embedded, cast in, or inserted
heating elements (not shown). The gas distribution assembly 608 is
constructed from materials that conduct heat to the face plate 203
such as aluminum.
[0022] FIG. 4 is a sectional view of another alternative embodiment
of the chamber of FIG. 2. This chamber 400 has a gas inlet passage
640 with an insert 401 along the top of the gas inlet passage 640.
The insert 401 is a ring shaped heater that is solid metal with an
embedded heating element. The insert 401 is clamped to the top of
the blocker plate 402. The insert 401 may be made out of an
aluminum alloy. The blocker plate 402 may also be made out of a
conductive material such as aluminum to facilitate heat transfer to
the face plate 203. The face plate 203 may also be made out of
aluminum.
[0023] FIG. 5 is a sectional view of another alternative embodiment
of the chamber of FIG. 2. This chamber 500 has a gas inlet passage
640 with an insert 501 on the top edge of the support 502 for the
face plate 203 and along the circumference of the bottom edge of
the blocker plate 602. The diameter of gas inlet passage 640 may be
reduced to accommodate the insert 501. The insert 501 may be made
out of an aluminum alloy. The insert 501 may have an embedded
heating element or the heating element may be located in grooves in
the middle of the insert 501.
[0024] In operation, the process and carrier gases may be preheated
prior to entering the gas inlet passage 640. Also, as the gas
enters the gas box, it is further heated by the various heating
elements shown in FIGS. 2-5. The gas then flows through the face
plate and enters the processing region of the chamber. The face
plate is heated directly by the gas as it leaves the gas inlet
passage and indirectly by the heat supplied to the gas box.
[0025] Heating the gas box indirectly heats the face plate which
may reduce recombination of the etchant species, hence improving
the etch rate. It also reduces deposition within the gas box and
hence reduces the clean time. This reduction in the clean time for
CVD processes when the deposition rate is inversely proportional to
temperature can be desirable for films such as carbon doped silicon
oxide, oxygen doped silicon carbide, silicon oxide, amorphous
carbon, and silicon nitride.
[0026] As the set point temperature of the gas inlet passage is
increased from 75 to 200.degree. C., the temperature of the face
plate edge increases from about 100 to about 175.degree. C. When
the temperature of the face plate edge is plotted as a function of
the set point temperature, the slope of the line is curved. As the
set point temperature of the gas inlet increases from 75 to
125.degree. C., the face plate edge temperature increases from
about 100 to about 110.degree. C. As the gas inlet set point
increases from 125 to 200.degree. C., the face plate edge
temperature increases from about 110 to about 175.degree. C.
[0027] When 9000 sccm of preheated helium at 6 Torr was introduced
to the heated gas inlet passage and processing region of a chamber
with 200 mm between the substrate and face plate, the temperature
of the edge and the center of the face plate was plotted as a
function of the set point temperature of the gas inlet passage. The
curve of the line for both the temperature at the center of the
face plate and the edge of the face plate were similar. The
temperature of the center of the face plate was about 80.degree. C.
warmer than the edge of the face plate.
[0028] To illustrate how the heated gas box influences carbon doped
silicon oxide film deposition, trimethylsilane in oxygen with
helium was introduced to the chamber. The gas box and substrate
support were heated to 120, 150, 175, and 200.degree. C. As the
temperature increased, the film thickness and film deposition rate
increased across the surface of the substrate and undesirable
deposit formation along the other chamber surfaces such as the face
plate decreased.
[0029] To illustrate how the heated gas box influences an
alternative carbon doped silicon oxide film deposition,
octamethylcyclotetrasiloxane and oxygen were introduced into the
chamber. The gas inlet passage and substrate support were heated to
120, 150, 175, and 200.degree. C. As the temperature increased, the
film thickness increased from about 7800 to about 9600 .ANG. during
60 second testing. The film deposition rate increased from about
7800 to about 9600 .ANG./min during 60 second testing.
[0030] A triethyloxysilane film on undoped silicon glass was etched
at different temperatures. A plot of etch rate as a function of the
substrate support and gas inlet passage temperature set point
revealed that as the temperature of the substrate support and the
gas inlet passage were increased, the etch rate of the film also
increased. The etch rate of a system with a gas inlet passage at
200.degree. C. was more than twice the etch rate of a conventional
system.
[0031] The etch rate across the surface of the substrate was
measured at the center, the edge, and half way between the edge and
the center of the substrate. A trimethylsilane film was deposited
on coupons. The etch was performed with the gas inlet passage at
200.degree. C. and the substrate support at 350.degree. C. for 15
seconds. NF.sub.3 was fed to the system at 2500 sccm with helium at
9000 sccm. The pressure was 6 Torr. The film was deposited in a 200
mm layer. One measurement was taken for the center and four
measurements were taken for the middle and edge of the substrate.
The average etch rate along the edge was about 115 k.ANG./min. The
average etch rate along the middle of the substrate was about 134
k.ANG./min. The center etch rate was about 120 k.ANG./min.
[0032] The chamber mount optical endpoint trace was measured when
the gas inlet passage was set to 200.degree. C. with 1500 sccm
NF.sub.3 and 1000 sccm He flow at 6 Torr. The plasma was set to 350
W. The film thickness was 450 mm. The voltage was measured as a
function of time. The endpoint for 1 mm of carbon doped silicon
oxide was approximately 70 seconds.
[0033] Repeatability tests with shorter clean times than
conventional system clean times yielded substrates that did not
have particle spikes. Also, the chamber was clean when inspected
after the repeatability tests.
[0034] While the foregoing is directed to embodiments of the
present invention, other and further emobdiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *