U.S. patent application number 14/195423 was filed with the patent office on 2017-12-21 for independent radiant gas preheating for precursor disassociation control and gas reaction kinetics in low temperature cvd systems.
This patent application is currently assigned to Applied Materials, Inc.. The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Howard BECKFORD, Brian Hayes BURROWS, Jeffery Ronald CAMPBELL, David Keith CARLSON, Herman DINIZ, Satheesh KUPPURAO, Xiaowei LI, Kailash Kiran PATALAY, Errol Antonio SANCHEZ, Zuoming ZHU.
Application Number | 20170362702 14/195423 |
Document ID | / |
Family ID | 39430471 |
Filed Date | 2017-12-21 |
United States Patent
Application |
20170362702 |
Kind Code |
A9 |
CARLSON; David Keith ; et
al. |
December 21, 2017 |
INDEPENDENT RADIANT GAS PREHEATING FOR PRECURSOR DISASSOCIATION
CONTROL AND GAS REACTION KINETICS IN LOW TEMPERATURE CVD
SYSTEMS
Abstract
In one embodiment, a gas distribution assembly includes an
injection block having at least one inlet to deliver a precursor
gas to a plurality of plenums from at least two gas sources, a
perforated plate bounding at least one side of each of the
plurality of plenums, at least one radiant energy source positioned
within each of the plurality of plenums to provide energy to the
precursor gas from one or both of the at least two gas sources and
flow an energized gas though openings in the perforated plate and
into a chamber, and a variable power source coupled to each of the
radiant energy sources positioned within each of the plurality of
plenums.
Inventors: |
CARLSON; David Keith; (San
Jose, CA) ; KUPPURAO; Satheesh; (San Jose, CA)
; BECKFORD; Howard; (Santa Clara, CA) ; DINIZ;
Herman; (Fremont, CA) ; PATALAY; Kailash Kiran;
(Santa Clara, CA) ; BURROWS; Brian Hayes; (San
Jose, CA) ; CAMPBELL; Jeffery Ronald; (Mountain View,
CA) ; ZHU; Zuoming; (Sunnyvale, CA) ; LI;
Xiaowei; (Austin, TX) ; SANCHEZ; Errol Antonio;
(Tracy, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Assignee: |
Applied Materials, Inc.
Santa Clara
CA
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140175054 A1 |
June 26, 2014 |
|
|
Family ID: |
39430471 |
Appl. No.: |
14/195423 |
Filed: |
March 3, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13175499 |
Jul 1, 2011 |
8663390 |
|
|
14195423 |
|
|
|
|
11937388 |
Nov 8, 2007 |
7976634 |
|
|
13175499 |
|
|
|
|
60866799 |
Nov 21, 2006 |
|
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/22 20130101;
H01L 21/0262 20130101; Y10T 137/0318 20150401; C23C 16/455
20130101; C23C 16/452 20130101; H01L 21/02532 20130101 |
International
Class: |
C23C 16/455 20060101
C23C016/455; C23C 16/22 20060101 C23C016/22; C23C 16/452 20060101
C23C016/452 |
Claims
1. A method of delivering a preheated precursor gas to a processing
region in a chamber, comprising: providing a precursor gas to a gas
distribution assembly in communication with the processing region;
heating the precursor gas at the point of introduction in the gas
distribution assembly using a radiant energy source; and
maintaining at least a portion of the heat provided to the
precursor gas along a flow path defined between the point of
introduction and the processing region.
2. The method of claim 1, further comprising: providing heat to the
flow path.
3. The method of claim 1, wherein the radiant energy source is
infrared light.
4. The method of claim 1, wherein the flow path is substantially
normal to a longitudinal axis of the chamber and the radiant energy
source is at least one infrared lamp disposed substantially
parallel to the flow path.
5. The method of claim 1, wherein the flow path is substantially
normal to a longitudinal axis of the chamber and the radiant energy
source is at least one infrared lamp disposed substantially normal
to the flow path.
6. The method of claim 1, wherein the point of introduction
comprises one or more introduction zones and the intensity of the
radiant energy source to the one or more introduction zones is
independently controlled by a variable power source.
7. The method of claim 1, wherein the point of introduction
comprises one or more introduction zones and the intensity of the
radiant energy source to the one or more introduction zones is
independently controlled by a filter element.
8. A gas distribution assembly comprising: an injection block
having at least one inlet to deliver a precursor gas to a plurality
of plenums from at least two gas sources; a perforated plate
bounding at least one side of each of the plurality of plenums; at
least one radiant energy source positioned within each of the
plurality of plenums to provide energy to the precursor gas from
one or both of the at least two gas sources and flow an energized
gas though openings in the perforated plate and into a chamber; and
a coolant source in communication with the at least one radiant
energy source, wherein the radiant energy sources are independently
controlled in each of the plurality of plenums.
9. The gas distribution assembly of claim 8, further comprising: a
sheath coupled to the at least one radiant energy source.
10. The gas distribution assembly of claim 8, further comprising: a
variable power source coupled to the at least one radiant energy
source.
11. The gas distribution assembly of claim 8, wherein each of the
at least one radiant energy sources comprise an infrared lamp.
12. The gas distribution assembly of claim 8, wherein the
perforated plate comprises a material that is transparent to
radiant energy.
13. The gas distribution assembly of claim 8, wherein at least a
portion of the plurality of plenums comprise an inner zone and an
outer zone and energy to each zone is independently controlled.
14. The gas distribution assembly of claim 8, wherein the energized
gas is directed to flow into the chamber in a direction that is
normal to a longitudinal axis of the chamber.
15. The gas distribution assembly of claim 8, wherein the gas
distribution assembly is coupled to the chamber normal to a
longitudinal axis of the chamber.
16. A gas distribution assembly comprising: an injection block
having at least one inlet to deliver a precursor gas to a plurality
of plenums from at least two gas sources; a perforated plate
bounding at least one side of each of the plurality of plenums; at
least one radiant energy source positioned within each of the
plurality of plenums to provide energy to the precursor gas from
one or both of the at least two gas sources and flow an energized
gas though openings in the perforated plate and into a chamber; and
a variable power source coupled to each of the radiant energy
sources positioned within each of the plurality of plenums.
17. The gas distribution assembly of claim 16, wherein each of the
radiant energy sources is an infrared lamp.
18. The gas distribution assembly of claim 16, wherein at least a
portion of the plurality of plenums comprise an inner zone and an
outer zone and energy to the radiant energy sources in each zone is
independently controlled.
19. The gas distribution assembly of claim 16, wherein the gas
distribution assembly comprises a quartz material that is
transparent to infrared light.
20. The gas distribution assembly of claim 16, wherein the
perforated plate comprises a transparent material that is
positioned downstream of the plurality of plenums.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/175,499 (Attorney Docket No. 11249USD01),
filed Jul. 1, 2011, and issued as U.S. Pat. No. 8,663,390 on Mar.
4, 2014, which is a divisional of U.S. patent application Ser. No.
11/937,388 (Attorney Docket No. 11249), filed Nov. 8, 2007, and
issued as U.S. Pat. No. 7,976,634 on Jul. 12, 2011, which claims
benefit of U.S. Provisional patent application Ser. No. 60/866,799
(Attorney Docket No. 11249L), filed Nov. 21, 2006, all of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Embodiments of the present invention generally relate to
preheating gases for a semiconductor fabrication process. More
specifically, to preheating gases used in deposition and etch
reactions on a semiconductor substrate, such as an epitaxial
deposition process or other chemical vapor deposition process.
[0004] 2. Description of the Related Art
[0005] Epitaxial growth of silicon and/or germanium-containing
films has become increasingly important due to new applications for
advanced logic and DRAM devices, among other devices. A key
requirement for these applications is a lower temperature process
so that device features will not be damaged during fabrication. The
lower temperature process is also important for future markets
where the feature sizes are in the range of 45 nm to 65 nm, and
avoidance of the diffusion of adjacent materials becomes critical.
Lower process temperatures may also be required for both substrate
cleaning prior to growth of the silicon and/or germanium-containing
epitaxial film and during selective or blanket growth of the
epitaxial film. By selective growth, it is generally meant that the
film grows on a substrate which includes more than one material on
the substrate surface, wherein the film selectively grows on a
surface of a first material of said substrate, with minimal to no
growth on a surface of a second material of said substrate.
[0006] Selective and blanket (non-selectively grown) epitaxial
films containing silicon and/or germanium, and strained embodiments
of such epitaxial films, which are grown at temperatures of less
than about 700.degree. C., are required for many current
semiconductor applications. Further, it may be desirable to have
the removal of native oxide and hydrocarbons prior to formation of
the epitaxial film accomplished at temperatures in the range of
about 650.degree. C. or less, although higher temperatures may be
tolerated when the removal time period is shortened.
[0007] This lower temperature processing is not only important to
forming a properly functioning device, but it minimizes or prevents
the relaxation of metastable strain layers, helps to prevent or
minimize dopant diffusion, and helps to prevent segregation of
dopant within the epitaxial film structure. Suppression of facet
formation and short channel effects, which is enabled by low
temperature processing (low thermal budget processing), is a
significant factor for obtaining high performance devices.
[0008] Current techniques for selective and blanket epitaxial
growth of doped and undoped silicon (Si), germanium (Ge), SiGe, and
carbon containing films, are typically carried out using reduced
pressure chemical vapor deposition (CVD), which is also referred to
as RPCVD or low pressure CVD (LPCVD). The typical reduced pressure
process, such as below about 200 Torr, is carried out at
temperatures above about 700.degree. C., typically above
750.degree. C., to get an acceptable film growth rate. Generally,
the precursor compounds for film deposition are silicon and/or
germanium containing compounds, such as silanes, germanes,
combinations thereof or derivatives thereof. Generally, for
selective deposition processes, these precursor compounds are
combined with additional reagents, such as chlorine (Cl.sub.2),
hydrogen chloride (HCl), and optionally hydrogen bromide (HBr), by
way of example. A carbon-containing silane precursor compound, for
example methylsilane (CH.sub.3SiH.sub.3), may be used as a dopant.
In the alternative, inorganic compounds, such as diborane
(B.sub.2H.sub.6), arsine (AsH.sub.3), and phosphine (PH.sub.3), by
way of example, may also be used as dopants.
[0009] In a typical LPCVD process to deposit an epitaxial layer on
a substrate, precursors are injected into a processing region in a
chamber by a gas distribution assembly, and the precursors are
energized above the surface of a substrate in the chamber by
irradiation of the precursors in the processing region, which is
typically low wavelength radiation, such as in the ultraviolet
and/or infrared spectrum. Plasma generation may also be used to
dissociate the reactants. The substrate temperature is typically
elevated to assist in adsorption of reactive species and/or
desorption of process byproducts, and it is desirable to minimize
the delta between the precursor temperature in the processing
region and the substrate temperature in order to optimize the
energization of the precursors and enhance the deposition or
desorption process.
[0010] To enable a more efficient dissociation process, it is
desirable to preheat the precursors prior to delivery to the
processing region to enable faster and more efficient dissociation
of the precursors above the substrate. Various methods to heat the
precursors have been employed, but challenges remain in stabilizing
the preheat temperature prior to energization above the substrate
surface. For example, the precursor temperature may be elevated to
a desired temperature at or before introduction to the gas
distribution assembly, but the precursor temperature may be lowered
by thermal losses in flowing through the gas distribution assembly
and/or along the flow path to the processing region above the
substrate.
[0011] Therefore, there is a need in the art for an apparatus and
method to minimize the temperature range delta between the
introduction temperature of precursors and the processing region,
and an apparatus and method of preheating precursors at the gas
introduction point that also minimizes heat loss prior to
dissociation of the precursor.
SUMMARY OF THE INVENTION
[0012] Embodiments described herein relate to an apparatus and
methods for delivering a process gas to a processing region within
a chamber.
[0013] In one embodiment, a method of delivering a preheated
precursor gas to a processing region in a chamber is provided. The
method includes providing a precursor gas to a gas distribution
assembly in communication with the processing region, heating the
precursor gas at the point of introduction in the gas distribution
assembly using a radiant energy source, and maintaining at least a
portion of the heat provided to the precursor gas along a flow path
defined between the point of introduction and the processing
region.
[0014] In another embodiment, a gas distribution assembly is
provided. The gas distribution assembly includes an injection block
having at least one inlet to deliver a precursor gas to a plurality
of plenums from at least two gas sources, a perforated plate
bounding at least one side of each of the plurality of plenums, at
least one radiant energy source positioned within each of the
plurality of plenums to provide energy to the precursor gas from
one or both of the at least two gas sources and flow an energized
gas though openings in the perforated plate and into a chamber, and
a coolant source in communication with the at least one radiant
energy source, wherein the radiant energy sources are independently
controlled in each of the plurality of plenums.
[0015] In another embodiment, a gas distribution assembly is
provided. The gas distribution assembly includes an injection block
having at least one inlet to deliver a precursor gas to a plurality
of plenums from at least two gas sources, a perforated plate
bounding at least one side of each of the plurality of plenums, at
least one radiant energy source positioned within each of the
plurality of plenums to provide energy to the precursor gas from
one or both of the at least two gas sources and flow an energized
gas though openings in the perforated plate and into a chamber, and
a variable power source coupled to each of the radiant energy
sources positioned within each of the plurality of plenums.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] 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.
[0017] FIG. 1 is a schematic cross-sectional view of one embodiment
of a deposition chamber.
[0018] FIG. 2 is a schematic top view of a portion of the
deposition chamber shown in FIG. 1.
[0019] FIG. 3 is a schematic side view of one embodiment of a gas
distribution assembly.
[0020] FIG. 4 is an isometric schematic view of another embodiment
of a gas distribution assembly.
[0021] FIG. 5 is an isometric schematic view of another embodiment
of a gas distribution assembly.
[0022] FIG. 6 is an isometric schematic view of another embodiment
of a gas distribution assembly.
[0023] To facilitate understanding, identical reference numerals
have been used, wherever possible, to designate identical elements
that are common to the figures. It is also contemplated that
elements disclosed in one embodiment may be beneficially utilized
on other embodiments without specific recitation.
DETAILED DESCRIPTION
[0024] FIG. 1 is a schematic cross-sectional view of a deposition
chamber 100 configured for epitaxial deposition, which may be part
of a CENTURA.RTM. integrated processing system available from
Applied Materials, Inc., of Santa Clara, Calif. The deposition
chamber 100 includes housing structure 101 made of a process
resistant material, such as aluminum or stainless steel, for
example 316 L stainless steel. The housing structure 101 encloses
various functioning elements of the process chamber 100, such as a
quartz chamber 130, which includes an upper chamber 105, and a
lower chamber 124, in which a processing volume 118 is contained.
Reactive species are provided to the quartz chamber 130 by a gas
distribution assembly 150, and processing byproducts are removed
from processing volume 118 by an outlet 138, which is typically in
communication with a vacuum source (not shown).
[0025] A substrate support 117 is adapted to receive a substrate
114 that is transferred to the processing volume 118. The substrate
support 117 is disposed along a longitudinal axis 102 of the
deposition chamber 100. The substrate support may be made of a
ceramic material or a graphite material coated with a silicon
material, such as silicon carbide, or other process resistant
material. Reactive species from precursor reactant materials are
applied to surface 116 of the substrate 114, and byproducts may be
subsequently removed from surface 116. Heating of the substrate 114
and/or the processing volume 118 may be provided by radiation
sources, such as upper lamp modules 110A and lower lamp modules
1108.
[0026] In one embodiment, the upper lamp modules 110A and lower
lamp modules 1108 are infrared (IR) lamps. Non-thermal energy or
radiation from lamp modules 110A and 1108 travels through upper
quartz window 104 of upper quartz chamber 105, and through the
lower quartz portion 103 of lower quartz chamber 124. Cooling gases
for upper quartz chamber 105, if needed, enter through an inlet 112
and exit through an outlet 113. Precursor reactant materials, as
well as diluent, purge and vent gases for the chamber 100, enter
through gas distribution assembly 150 and exit through outlet
138.
[0027] The low wavelength radiation in the processing volume 118,
which is used to energize reactive species and assist in adsorption
of reactants and desorption of process byproducts from the surface
116 of substrate 114, typically ranges from about 0.8 .mu.m to
about 1.2 .mu.m, for example, between about 0.95 .mu.m to about
1.05 .mu.m, with combinations of various wavelengths being
provided, depending, for example, on the composition of the film
which is being epitaxially grown. In another embodiment, the lamp
modules 110A and 1108 may be ultraviolet (UV) light sources. In one
embodiment, the UV light source, is an excimer lamp. In another
embodiment, UV light sources may be used in combination with IR
light sources in one or both of the upper quartz chamber 105 and
lower quartz chamber 124. An example of UV radiation sources used
in combination with IR radiation sources can be found in U.S.
patent application Ser. No. 10/866,471, filed Jun. 10, 2004, which
published on Dec. 15, 2005, as United States patent publication No.
2005/0277272, which is incorporated by reference in its
entirety.
[0028] The component gases enter the processing volume 118 via gas
distribution assembly 150. Gas flows from the gas distribution
assembly 150 and exits through port 138 as shown generally at 122.
Combinations of component gases, which are used to clean/passivate
a substrate surface, or to form the silicon and/or
germanium-containing film that is being epitaxially grown, are
typically mixed prior to entry into the processing volume. The
overall pressure in the processing volume 118 may be adjusted by a
valve (not shown) on the outlet port 138. At least a portion of the
interior surface of the processing volume 118 is covered by a liner
131. In one embodiment, the liner 131 comprises a quartz material
that is opaque. In this manner, the chamber wall is insulated from
the heat in the processing volume 118.
[0029] The temperature of surfaces in the processing volume 118 may
be controlled within a temperature range of about 200.degree. C. to
about 600.degree. C., or greater, by the flow of a cooling gas,
which enters through a port 112 and exits through port 113, in
combination with radiation from upper lamp modules 110A positioned
above upper quartz window 104. The temperature in the lower quartz
chamber 124 may be controlled within a temperature range of about
200.degree. C. to about 600.degree. C. or greater, by adjusting the
speed of a blower unit which is not shown, and by radiation from
the lower lamp modules 1108 disposed below lower quartz chamber
124. The pressure in the processing volume 118 may be between about
0.1 Torr to about 600 Torr, such as between about 5 Torr to about
30 Torr.
[0030] The temperature on the substrate 114 surface 116 may be
controlled by power adjustment to the lower lamp modules 1108 in
lower quartz chamber 124, or by power adjustment to both the upper
lamp modules 110A overlying upper quartz chamber 104, and the lower
lamp modules 1108 in lower quartz chamber 124. The power density in
the processing volume 118 may be between about 40 W/cm.sup.2 to
about 400 W/cm.sup.2, such as about 80 W/cm.sup.2 to about 120
W/cm.sup.2.
[0031] In one aspect, the gas distribution assembly 150 is disposed
normal to, or in a radial direction 106 relative to, the
longitudinal axis 102 of the chamber 100 or substrate 114. In this
orientation, the gas distribution assembly 150 is adapted to flow
process gases in a radial direction 106 across, or parallel to, the
surface 116 of the substrate 114. In one application, the process
gases are preheated at the point of introduction to the chamber 100
to initiate preheating of the gases prior to introduction to the
processing volume 118, and/or to break specific bonds in the gases.
In this manner, surface reaction kinetics may be modified
independently from the thermal temperature of the substrate
114.
[0032] FIG. 2 is a schematic top view of a portion of a deposition
chamber 100 similar the chamber shown in FIG. 1, with the exception
of the substrate 114 not being shown. A gas distribution assembly
150 is shown coupled to the housing structure 101. The gas
distribution assembly 150 includes an injection block 210 coupled
to one or more gas sources 140A and 140B. The gas distribution
assembly 150 also includes a non-thermal heating assembly 220,
which includes a plurality of radiant heat sources, such as IR
lamps 225A-225F disposed at least partially in the injection block
210. The injection block 210 also includes one or more plenums
224.sub.N disposed upstream of the openings 158 of a perforated
plate 154, such as inner plenum 224.sub.2 and outer plenums
224.sub.1 and 224.sub.3, and the IR lamps 225A-225F are disposed at
least partially in the plenums 224.sub.N.
[0033] Although six IR lamps are shown, the gas distribution
assembly 150 may include more or less IR lamps. The IR lamps
225A-225F may include halogen type lamps, or rapid thermal
processing (RTP) lamps with a wattage between about 300 watts to
about 1200 watts, depending on the intensity of the radiation
needed for the particular process, and/or the number of IR lamps
used with the gas distribution assembly 150. In the embodiment
shown, the IR lamps 225A-225F are RTP style lamps having a wattage
between about 500 watts to about 750 watts, for example between
about 500 watts to about 550 watts with about an 80 volt power
application. In one application, the power density provided by each
of the IR lamps 225A-225F may be between about 25 W/cm.sup.2 to
about 40 W/cm.sup.2 in the plenums 224.sub.N. In one embodiment,
the IR lamps 225A-225F provide a variable temperature in each
plenum 224.sub.N of about 50.degree. C. to about 250.degree. C.
[0034] In operation, precursors to form Si and SiGe blanket or
selective films are provided to the gas distribution assembly 150
from the one or more gas sources 140A and 140B. The gas sources
140A, 140B may be coupled the gas distribution assembly 150 in a
manner configured to facilitate introduction zones within the gas
distribution assembly 150, such as an outer zone that is shown as
outer plenums 224.sub.1 and 224.sub.3, and an inner zone, shown as
inner plenum 224.sub.2. The gas sources 140A, 140B may include
valves (not shown) to control the rate of introduction into the
plenums 224.sub.N. Alternatively, the plenums 224.sub.N may be in
communication with one gas source, or other gas sources may be
added to create more introduction zones.
[0035] The gas sources 140A, 140B may include silicon precursors
such as silanes, including silane (SiH.sub.4), disilane
(Si.sub.2H.sub.6,), dichlorosilane (SiH.sub.2Cl.sub.2),
hexachlorodisilane (Si.sub.2Cl.sub.6), dibromosilane
(SiH.sub.2Br.sub.2), higher order silanes, derivatives thereof, and
combinations thereof. The gas sources 140A, 140B may also include
germanium containing precursors, such as germane (GeH.sub.4),
digermane (Ge.sub.2H.sub.6), germanium tetrachloride (GeCl.sub.4),
dichlorogermane (GeH.sub.2Cl.sub.2), derivatives thereof, and
combinations thereof. The silicon and/or germanium containing
precursors may be used in combination with hydrogen chloride (HCl),
chlorine gas (Cl.sub.2), hydrogen bromide (HBr), and combinations
thereof. The gas sources 140A, 140B may include one or more of the
silicon and germanium containing precursors in one or both of the
gas sources 140A, 140B. For example, the gas source 140A, which may
be in communication with the outer plenums 224.sub.1 and 224.sub.3,
may include precursor materials, such as hydrogen gas (H.sub.2) or
chlorine gas (Cl.sub.2), while gas source 140B may include silicon
and/or germanium containing precursors, derivatives thereof, or
combinations thereof.
[0036] The precursor materials from the gas sources 140A, 140B are
delivered to the plenums 224.sub.N and the non-thermal energy from
the IR lamps 225A-225F illuminates the precursor materials with IR
energy in the plenums 224.sub.N at the point of introduction. The
wavelength of the non-thermal energy resonates and excites the
precursor materials by taking advantage of the vibrational stretch
mode of the precursor materials, and the energy is absorbed into
the precursor materials, which preheats the precursor materials
prior to entry into the processing volume. The injection block 210,
which contains the IR lamps 225A-225F, is made of a material with
high reflectivity, such as stainless steel, which may also include
a polished surface to increase reflectivity. The reflective quality
of the material for the injection block 210 may also act as an
insulator to minimize heating of the injection block, thus
increasing safety to personnel that may be in close proximity to
the injection block 210. In one embodiment, the injection block 210
comprises stainless steel and the interior surfaces of the plenums
224.sub.N are polished. In another embodiment, the injection block
210 comprises aluminum and the interior surfaces of the plenums
224.sub.N are polished.
[0037] The precursor materials enter the processing volume 118
through openings 158 in the perforated plate 154 in this excited
state, which in one embodiment is a quartz material, having the
openings 158 formed therethrough. In this embodiment, the
perforated plate is transparent to IR energy, and may be made of a
clear quartz material. In other embodiments, the perforated plate
154 may be any material that is transparent to IR energy and is
resistant to process chemistry and other process parameters. The
energized precursor materials flow toward the processing volume 118
through a plurality of holes 158 in the perforated plate 154, and
through a plurality of channels 152.sub.N. A portion of the photons
and non-thermal energy from the IR lamps 225A-225F also passes
through the holes 158, the perforated plate 154, and channels
152.sub.N, facilitated by the high reflective material and/or
surface of the injection block 210, thereby illuminating the flow
path of the precursor materials (shown as arrow 325 in FIG. 3). In
this manner, the vibrational energy of the precursor materials may
be maintained from the point of introduction to the processing
volume 118 along the flow path.
[0038] Intensity of the IR wavelengths in the plurality of IR lamps
225A-225F may be increased or decreased depending on the process.
In one application, intensity of the IR lamps may be controlled by
filter elements 405 (FIG. 4), and window 610 (FIG. 6). In another
embodiment, a sheath 315 (FIG. 3) may be disposed over at least a
portion of the IR lamps 225A-225F, and the sheath may be configured
as a filter element to control the intensity of the lamps. In one
example, the filter elements may be a sleeve, sheet, or lens
adapted to modulate bandwidth by selective transmission of specific
wavelengths. The filter elements may be used on at least one of the
IR lamps 225A-225F or all of the IR lamps 225A-225F. Alternatively,
different filter elements may be used on different IR lamps
225A-225F. In one example, the outer plenums 224.sub.1 and
224.sub.3 may receive a first level of intensity by using a first
filter configured to absorb or block specific spectra, while the
inner plenum 224.sub.2 receives a second level of intensity by
using a second filter configured to absorb or block a different
specific spectra.
[0039] In another application that may be used alone or in
combination with filters, the IR intensity in the multiple zones
defined by the plenums 224.sub.N may be individually controlled by
leads 226A-226F coupled to a power source 205 and a controller. For
example, the outer plenums 224.sub.1 and 224.sub.3 may receive a
first level of intensity, while the inner plenum 224.sub.2 receives
a second level of intensity by variation of signals provided to the
IR lamps 225A-225F. Alternatively, each IR lamp 225A-225F may be
controlled separately by variation of signals provided by the
controller. The intensity of the IR lamps 225A-225F may be
controlled in an open-loop mode, or a closed-loop mode. Thus, the
precursor materials enter the processing volume 118 in a preheated
or energized state, which may lessen the adsorption or desorption
time frame or disassociation time, which, in turn, increases
throughput.
[0040] FIG. 3 is a schematic side view of one embodiment of a gas
distribution assembly 150 as shown in FIGS. 1 and 2. An aperture
305 is formed in the injection block 210 to receive a portion of an
IR lamp 225C, which is at least partially inserted into the plenum
224.sub.2. Precursor materials are supplied to the plenum 224.sub.2
by a port 320 disposed in the injection block 210. The aperture 305
may be sized slightly larger than the IR lamp 225C to allow space
for a sheath 315 adapted to encase a portion of the IR lamp 225C.
In one embodiment, the sheath 315 is made of a material transparent
to IR energy, such as quartz, magnesium fluoride, calcium fluoride,
sapphire, as examples. In another embodiment, the sheath 315 may be
adapted as a filter element to modulate bandwidth by selective
transmission of specific wavelengths. Temperature sensing devices
(not shown), such as thermocouples, may be disposed in the
injection block 210 to monitor the sheath temperature and/or the
temperature in the plenum 224.sub.2. The aperture 305 also includes
a larger diameter portion at the end opposite the plenum 224.sub.2
to receive a high temperature seal 323, for example an o-ring made
of a polymeric material adapted to withstand elevated temperatures,
such as a Teflon.RTM. material, polyethernitrile,
polyetheretherketone (PEEK), polyaryletherketone (PAEK), among
others.
[0041] Referring to FIGS. 2 and 3, the IR lamps 225A-225F are
coupled to a cooling device 310 to cool the IR lamps 225A-225F. In
one application, the cooling device 310 includes a conduit, such as
a tubular member 156 having an inlet port 260A and an outlet port
260B, and is adapted to provide a coolant to a plurality of IR
lamps 225A-225F. In other embodiments (not shown in FIGS. 2 and 3),
the cooling device may be housing coupled to a single IR lamp. The
cooling device 310 may comprise a cooling fluid, such as a liquid
or gas from a coolant source 311 that circulates through the
tubular member 156 to facilitate heat transfer from the IR lamps
225A-225F. The tubular member 156 also includes apertures 306
adapted to receive a portion of the IR lamps 225A-225F. At least
one of the apertures includes a fitting 308, such as a stainless
steel VCO fitting, adapted to receive a portion of the IR lamp and
seal the tubular member 156. In one embodiment, the cooling fluid
from the coolant source 311 is nitrogen gas, which is circulated
through the tubular member 156.
[0042] In operation, in reference to FIG. 3, precursor materials
from gas source 140B are introduced to the plenum 224.sub.2 by the
port 320, and the precursor materials are radiantly heated by the
IR lamp 225C at this point of introduction. The lower partial
pressure in the processing volume 118 (not shown in this view)
creates a flow path 325 through the opening 158 and the channel
152.sub.N. The precursor materials are energized in the plenum
224.sub.2 and remain energized along the flow path 325 by the
non-thermal energy reflected and/or passing into the channel
152.sub.N. Thus, preheating of the precursor materials, and
maintenance of the energized precursor materials, is enhanced.
Using this non-thermal energy minimizes or eliminates the need for
resistive or convective heating elements in or near the precursor
introduction point, which may improve safety of the use of the
chamber, and minimizes the need for extended cooling systems for
the chamber.
[0043] FIGS. 4-6 are isometric schematic views of various
embodiment of a gas distribution assembly 150 that may be coupled
with the chamber 100 of FIG. 1. The gas distribution assembly 150
includes an injection block 210 having at least one IR lamp 425 in
communication with a gas source, such as gas source 140A and/or
140B coupled to ports 320. While not shown, each port is in
communication with a plenum 224.sub.N disposed within the gas
injection block 210. In the embodiments depicted in FIGS. 4-6, each
IR lamp 425 is individually coupled to the injection block 210 by a
housing 410 that provides electrical connections (not shown) and
cooling capabilities. In one embodiment, each housing 410 includes
a port 415 that may be coupled to the coolant source 311 (FIG. 3).
In one application, each port 415 functions as an inlet and an
outlet for cooling fluid.
[0044] In the embodiment shown in FIG. 4, a plurality of IR lamps
425 are disposed in a radial direction to the chamber 100 (FIG. 1).
In this embodiment, each IR lamp 425 is disposed normal to a gas
injection path as defined by the directional orientation of the
ports 320. Additionally, one or more IR lamps 425 may include a
filter element 405 adapted to modulate bandwidth by selective
transmission of specific wavelengths from the IR lamp 425. The
filter element 405 may be a sheath, a plate, a sheet, or any
article or device adapted block specific wavelengths.
[0045] In the embodiment shown in FIG. 5, a plurality of IR lamps
425 are disposed in a parallel orientation relative to the
longitudinal axis of the chamber 100 (FIG. 1). In this embodiment,
each IR lamp 425 is disposed substantially parallel to a gas
injection path as defined by the directional orientation of the
ports 320. While not shown, one or more IR lamps 425 may include a
filter element (FIG. 4) adapted to modulate bandwidth by selective
transmission of specific wavelengths from the IR lamp 425.
[0046] In the embodiment shown in FIG. 6, a single IR lamp 425 is
disposed in a radial direction to the chamber 100 (FIG. 1). In this
embodiment, the IR lamp 425 is disposed normal to a gas injection
path as defined by the directional orientation of the ports 320.
Additionally, the gas injection block 210 may include a plate 610
positioned between the IR lamp 425 and plenums 224.sub.N (not shown
in this view). In one embodiment, the plate 610 may be configured
as a window made of a material that is transparent to IR light. In
another embodiment, the plate 610 may be configured as a filter
element adapted to modulate bandwidth by selective transmission of
specific wavelengths from the IR lamp 425. In yet another
embodiment, the plate 610 may be adapted as a filter element having
multiple zones 615A, 615B adapted block specific wavelengths in
each zone.
EXAMPLES
[0047] In one example, a blanket SiGe film was formed on a 300 mm
wafer in the chamber 100 using the gas distribution assembly 150 as
shown in FIG. 2. The chamber was provided with a pressure of about
10 Torr and a surface temperature in the processing region 118 of
about 750.degree. C. with a power density of about 45 W/cm.sup.2.
Dichlorosilane and germane was introduced to the processing region
118 from the gas distribution assembly 150 at about 0.5% and 0.01%,
respectively. Non-thermal energy from the IR lamps 225A-225F
operating at a power of about 30 watts produced a temperature
measured at the sheath 315 of about 138.degree. C. This produced a
noticeable decrease in film growth rate and an increase in the
percentage of germanium in the film.
[0048] In another example, a selective SiGe film was formed on a
300 mm wafer in the chamber 100 using the gas distribution assembly
150 as shown in FIG. 2. The chamber was provided with a pressure of
about 10 Torr and a surface temperature in the processing region
118 of about 750.degree. C. with a power density of about 45
W/cm.sup.2. Dichlorosilane and germane was introduced to the
processing region 118 from the gas distribution assembly 150 at
about 0.5% and 0.01%, respectively. Hydrogen chloride was also
provided at about 0.5%. Non-thermal energy from the IR lamps
225A-225F operating at a power of about 30 watts produced a
temperature measured at the sheath 315 of about 138.degree. C. This
produced a significant decrease in film growth rate and an improved
film profile.
[0049] In another example, a selective SiGe film was formed on a
300 mm wafer in the chamber 100 using the gas distribution assembly
150 as shown in FIG. 2. The chamber was provided with a pressure of
about 10 Torr and a surface temperature in the processing region
118 of about 750.degree. C. with a power density of about 45
W/cm.sup.2. Silane and hydrogen chloride was introduced to the
processing region 118 from the gas distribution assembly 150 at
about 0.25% and 1.125%, respectively. Non-thermal energy from the
IR lamps 225A-225F operating at a power of about 25 watts produced
a temperature measured at the sheath 315 of about 110.degree. C.
This produced a noticeable increase in percentage of germanium in
the film and a decrease in film growth rate.
[0050] In another example, a selective SiGe film was formed on a
300 mm wafer in the chamber 100 using the gas distribution assembly
150 as shown in FIG. 2. The chamber was provided with a pressure of
about 10 Torr and a surface temperature in the processing region
118 of about 750.degree. C. with a power density of about 45
W/cm.sup.2. Silane and germane was introduced to the processing
region 118 from the gas distribution assembly 150 at 0.25% and
1.225%, respectively. Hydrogen chloride was also provided at about
0.575%. Non-thermal energy from the IR lamps 225A-225F operating at
a power of about 25 watts produced a temperature measured at the
sheath 315 of about 110.degree. C. This produced a significant
decrease in film growth rate (about 56.5 .ANG./minute) and an
increase in the percentage of germanium in the film (about
0.25%).
[0051] While the foregoing is directed to embodiments of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof, and
the scope thereof is determined by the claims that follow.
* * * * *