U.S. patent application number 10/714214 was filed with the patent office on 2008-06-05 for housing assembly for an induction heating device including liner or susceptor coating.
Invention is credited to Michael James Paisley, Joseph John Sumakeris.
Application Number | 20080127894 10/714214 |
Document ID | / |
Family ID | 21782889 |
Filed Date | 2008-06-05 |
United States Patent
Application |
20080127894 |
Kind Code |
A1 |
Sumakeris; Joseph John ; et
al. |
June 5, 2008 |
HOUSING ASSEMBLY FOR AN INDUCTION HEATING DEVICE INCLUDING LINER OR
SUSCEPTOR COATING
Abstract
A housing assembly for an induction heating device defines a
processing chamber and includes a susceptor and a thermally
conductive liner. The susceptor surrounds at least a portion of the
processing chamber. The thermally conductive liner is interposed
between the susceptor and the processing chamber. The liner is
separately formed form the susceptor. The liner is removable from
the susceptor without requiring disassembly of the susceptor.
Inventors: |
Sumakeris; Joseph John;
(Apex, NC) ; Paisley; Michael James; (Garner,
NC) |
Correspondence
Address: |
MYERS BIGEL SIBLEY & SAJOVEC
PO BOX 37428
RALEIGH
NC
27627
US
|
Family ID: |
21782889 |
Appl. No.: |
10/714214 |
Filed: |
November 14, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10017492 |
Oct 30, 2001 |
6896738 |
|
|
10714214 |
|
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|
|
Current U.S.
Class: |
118/725 ;
219/634 |
Current CPC
Class: |
C30B 25/10 20130101;
C23C 16/4581 20130101; H05B 6/108 20130101; C23C 16/46
20130101 |
Class at
Publication: |
118/725 ;
219/634 |
International
Class: |
H05B 6/10 20060101
H05B006/10; C23C 16/00 20060101 C23C016/00 |
Goverment Interests
STATEMENT OF GOVERNMENT SUPPORT
[0002] The present invention was made with Government support under
Air Force Research Laboratory Contract No. F336 615-00-C-5403
awarded by the United States Air Force. The Government has certain
rights in this invention.
Claims
1. The heating device of claim 5 wherein the liner is removable
from the susceptor without requiring disassembly of the
susceptor.
2. The heating device of claim 1 including: a first susceptor
portion and a second susceptor portion disposed on opposed sides of
the processing chamber, wherein the liner is disposed between the
first susceptor portion and the processing chamber; and a second
liner disposed between the second susceptor portion and the
processing chamber.
3. The heating device of claim 5 wherein the susceptor includes a
platter region, the housing assembly further including: a platter
adapted to support the article disposed in the processing chamber
and overlying the platter region; and an opening defined in the
liner and overlying the platter region.
4. The heating device of claim 5 wherein the liner varies in
thickness along at least a portion of its length.
5. A heating device comprising: a housing assembly defining a
processing chamber and including: a susceptor surrounding at least
a portion of the processing chamber; and a thermally conductive
liner interposed between the susceptor and the processing chamber,
wherein the liner is separately formed from the susceptor; wherein
the susceptor includes a susceptor core of a first material and a
susceptor coating of a second material; wherein the second material
is selected from the group consisting of refractory metal carbides;
and wherein the liner is interposed between the susceptor coating
and the processing chamber; and an EMF generator configured to
generate an electromagnetic field to induce eddy currents within
the susceptor, wherein the susceptor converts the eddy currents to
heat.
6. The heating device of claim 5 wherein the second material is
TaC.
7. The heating device of claim 5 wherein the first material is
graphite.
8. The heating device of claim 3 wherein the platter region is
exposed through the opening in the liner.
9. The heating device of claim 3 wherein the platter is received in
the opening in the liner.
10. The heating device of claim 3 wherein the platter is adapted to
rotate relative to the susceptor.
11. The heating device of claim 4 wherein the liner contacts the
susceptor.
12. The heating device of claim 5 wherein the liner includes a
portion formed of SiC interfacing with the processing chamber.
Description
RELATED APPLICATION(S)
[0001] The present application is a continuation application of and
claims priority from U.S. patent application Ser. No. 10/017,492,
filed Oct. 30, 2001, the disclosure of which is hereby incorporated
herein by reference in its entirety.
FIELD OF THE INVENTION
[0003] The present invention relates to methods and apparatus for
controllably heating an article and, more particularly, to methods
and apparatus for induction heating.
BACKGROUND OF THE INVENTION
[0004] Silicon carbide (SiC) is increasingly recognized as an
effective semiconductor material for electronic devices. SiC
possesses a number of properties that make it particularly
attractive for applications requiring devices to operate at high
temperature, power and/or frequency. SiC exhibits highly efficient
heat transfer and is capable of withstanding high electric
fields.
[0005] It has been demonstrated that hot-wall chemical vapor
deposition (CVD) reactors can provide epitaxial layers of SiC with
morphology and doping superior to cold-wall systems. See, for
example. U.S. Pat. No. 5,695,567 to Kordina et al., the disclosure
of which is hereby incorporated herein by reference. In certain
processes, such as epitaxial growth processes, management of the
thermal profile in the vicinity of the substrate may be of great
importance. Temperature gradients may dramatically influence many
growth parameters and the qualities of the resulting layers. Where
the substrate is disposed on a platter (e.g., for rotation)
separate from a surrounding susceptor and induction heating is
employed, the platter may be significantly cooler than the internal
surfaces of the susceptor. More particularly, the susceptor may be
directly heated by an RF field while the platter is only or
predominantly heated by thermal conduction and radiation from the
susceptor. The substrate may be cooler even than the platter. As a
result, a substantial thermal gradient may be manifested between
the substrate growth surface and the internal surfaces of the
susceptor. The thermal gradient may be further exacerbated by the
cooling effect of a process gas flow through the susceptor.
[0006] The aforementioned temperature gradient may present a number
of problems. Such problems may include the formation of loose
deposits (SiC) on the hot susceptor wall. Such deposits may fall
onto the substrate and be incorporated into the epilayers.
Moreover, temperature gradients may cause difficulty in controlling
material properties as a result of non-controllable variations in
the temperature gradient and the narrowing of process windows.
[0007] The foregoing problems may also be presented in other types
of processes such as other types of deposition processes and
annealing processes.
SUMMARY OF THE INVENTION
[0008] According to embodiments of the present invention, a heating
device for controllably heating an article defines a processing
chamber to hold the article and includes a housing and an EMF
generator. The housing includes a susceptor portion surrounding at
least a portion of the processing chamber, and a conductor portion
interposed between the susceptor portion and the processing
chamber. The EMF generator is operable to induce eddy currents
within the susceptor portion such that substantially 110 eddy
currents are induced in the conductor portion. The conductor
portion is operative to conduct heat from the susceptor portion to
the processing chamber. The heating device may further include a
platter and an opening defined in the conductor portion, wherein
the opening is interposed between the susceptor portion and the
platter.
[0009] According to embodiments of the present invention, a housing
assembly for an induction heating device defines a processing
chamber and includes a susceptor surrounding at least a portion of
the processing chamber. A thermally conductive liner is interposed
between the susceptor and the processing chamber. The liner is
separately formed from the susceptor.
[0010] The susceptor may include a platter region and the housing
assembly may further include: a platter adapted to support the
article disposed in the processing chamber and overlying the
platter region; and an opening defined in the liner and interposed
between the platter region and the platter.
[0011] According to method embodiments of the present invention, a
method for controllably heating an article includes positioning the
article in a processing chamber. An electromagnetic field is
applied to a housing about the processing chamber such that eddy
currents are induced within an outer, susceptor portion of the
housing and such that substantially no eddy currents are induced in
an inner, conductor portion of the housing. Heat is conducted from
the susceptor portion to the processing chamber through the
conductor portion.
[0012] Objects of the present invention will be appreciated by
those of ordinary skill in the art from a reading of the figures
and the detailed description of the preferred embodiments which
follow, such description being merely illustrative of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is an exploded, perspective view of a housing
assembly according to embodiments of the present invention;
[0014] FIG. 2 is a perspective view of the housing assembly of FIG.
1;
[0015] FIG. 3 is a perspective view of a reactor assembly according
to embodiments of the present invention and including the housing
assembly of FIG. 1;
[0016] FIG. 4 is an end view of the reactor assembly of FIG. 3;
[0017] FIG. 5 is a top plan view of a bottom susceptor member
forming a part of the housing assembly of FIG. 1:
[0018] FIG. 6 is a side elevational view of the bottom susceptor
member of FIG. 5;
[0019] FIG. 7 is a cross-sectional view of the bottom susceptor
member of FIG. 5 taken along the line 7-7 of FIG. 5;
[0020] FIG. 8 is a cross-sectional view of a top susceptor member
forming a part of the housing assembly of FIG. 1 taken along the
line 8-8 of FIG. 1;
[0021] FIG. 9 is a cross-sectional view of a side susceptor member
forming a part of the housing assembly of FIG. 1 taken along the
line 9-9 of FIG. 1;
[0022] FIG. 10 is a bottom plan view of a bottom liner forming a
part of the housing assembly of FIG. 1;
[0023] FIG. 11 is a side elevational view of the bottom liner of
FIG. 10;
[0024] FIG. 12 is an end view of a rear liner member forming a part
of the bottom liner of FIG. 10;
[0025] FIG. 13 is a cross-sectional view of the bottom liner of
FIG. 14 taken along the line 13-13 of FIG. 10;
[0026] FIG. 14 is a bottom plan view of a top liner forming a part
of the housing assembly of FIG. 1;
[0027] FIG. 15 is a side elevational view of the top liner of FIG.
14;
[0028] FIG. 16 is a cross-sectional view of the top liner of FIG.
14 taken along the line 16-16 of FIG. 14; and
[0029] FIG. 17 is a cross-sectional view of a platter forming a
part of the housing assembly of FIG. 1 taken along the line 17-17
of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The present invention now is described more fully
hereinafter with reference to the accompanying drawings, in which
preferred embodiments of the invention are shown. This invention
may, however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0031] With reference to FIGS. 1-4, a housing assembly 100 and a
heating device or reactor assembly 10 including the same according
to embodiments of the present invention are shown therein. For the
purposes of description, the housing assembly 100 has a front end
104A and a rear end 106A (FIG. 2). With reference to FIGS. 3 and 4,
the reactor assembly 10 further includes insulation covers 16, 18
surrounding the housing assembly 100. An electromagnetic field
(EMF) generator 11 is provided including an electrically conductive
coil 14 surrounding the covers 16, 18 and a power supply 12 as
discussed in greater detail below. The reactor assembly 10 serves
as a portion of a hot-wall CVD reactor for processing substrates 5
(FIG. 1) such as semiconductor wafers using an atmosphere or flow
of a processing gas IG (FIG. 2).
[0032] Turning to the housing assembly 100 in more detail, the
housing assembly 100 includes a bottom susceptor member 110, a top
susceptor member 120 and a pair of side susceptor members 130
joined by pins 139 and arranged to form a box that is open at
opposed ends. A bottom conductor member or liner 150 is mounted on
the bottom susceptor member 110. The bottom liner 150 includes a
front liner member 154 and a rear liner member 152 which are
separable from one another and together define an opening 156
therebetween. The opening 156 overlies and exposes a platter region
112 on the bottom susceptor member 110. A platter 140 overlies the
platter region 112 and is received in the opening 156. The platter
140 is rotatably centered by a pivot pin 149. A top conductor or
liner 160 overlies the platter 140. The top liner 160 is supported
by flange portions 163 that are interposed between the top
susceptor member 120 and the side susceptor members 130 on either
side of the housing assembly 100.
[0033] With reference to FIG. 2, the housing assembly 100 defines a
processing chamber or passage 102 extending fully through the
housing assembly 100 and communicating with an inlet opening 104
and an outlet opening 106. More particularly, the passage 102 is
defined by the interior surfaces of the bottom liner 150, the top
liner 160, the side susceptor members 130 and the platter 140.
[0034] Referring to FIGS. 5 and 6, the bottom susceptor member 110
includes holes 110A to receive the pins 139 or other fasteners. The
platter region 112 may be adapted to provide gas driven rotation of
the platter 140, for example, as disclosed in U.S. patent
application Ser. No. 09/756,548, titled Gas-Driven Rotation
Apparatus and Method for Forming Silicon Carbide Layers, filed Jan.
8, 2001, inventors Paisley et al., the disclosure of which is
hereby incorporated herein in its entirety. An annular, upstanding
ridge 114 surrounds the platter region 112. An upstanding tab 110B
is disposed adjacent the rear end of the bottom susceptor member
110.
[0035] With reference to FIG. 7, the bottom susceptor member 110
includes a core 115 and a surrounding layer or coating 117.
Preferably, the coating 117 completely surrounds the core 115. The
core 115 is formed of a material that has high purity, is able to
withstand high temperatures (e.g., having a melting point greater
than 1800.degree. C.), has low chemical reactivity, and has
acceptably low electrical resistance. Preferably, the material of
the core 115 has an electrical resistivity of no more than about
100.times.10.sup.-6 ohm-meter. Preferably, the core 115 is formed
of graphite (preferably high purity graphite).
[0036] The coating 117 is formed of a material that has high
purity, is able to withstand high temperatures (e.g., having a
melting point greater than 1800.degree. C., has low chemical
reactivity, and has acceptably low electrical resistance).
Preferably, the material of the coating 117 has a resistivity that
is less than the resistivity of the core 115. More preferably, the
material of the coating 117 has a resistivity that is no more than
20% of the resistivity of the core 115. Preferably, the material of
the coating 117 has a resistivity of no more than about
20.times.10.sup.-6 ohm-meters. Preferably, the coating 117 is
formed of SiC or a refractory metal carbide, more preferably TaC,
NbC, and/or TIC. Most preferably, the coating 117 is formed of
tantalum carbide (TaC). The coating 117 may be applied to the core
115 by any suitable method. Preferably, the coating 117 is a dense,
impervious coating. Preferably, the coating 117 has a thickness of
at least about 10 microns.
[0037] With reference to FIGS. 1 and 8, the top susceptor member
120 includes holes 120A to receive the pins 139 or other fasteners.
With reference to FIG. 8, the top susceptor member 120 includes a
core 125 and a surrounding layer or coating 127. Preferably, the
coating 127 completely surrounds the core 125. The core 125 may be
formed of the same materials as discussed above with regard to the
core 115, with the same material(s) being preferred. The coating
127 may be formed of the same materials and in the same dimensions
as discussed above with regard to the coating 117, with the same
material(s) and dimensions being preferred, and may be applied to
the core 125 in the manner described above.
[0038] With reference to FIGS. 1 and 9, each side susceptor member
130 includes holes 130A to receive the pins 139 or other fasteners.
With reference to FIG. 9, the side susceptor member 130 includes a
core 135 and a surrounding layer or coating 137. Preferably, the
coating 137 completely surrounds the core 135. The core 135 may be
formed of the same materials as discussed above with regard to the
core 115, with the same material(s) being preferred. The coating
137 is preferably formed of an impervious material. More
preferably, the coating 137 is formed of SiC (preferably dense SiC
that is impervious and has a 0% porosity). The coating 137 may be
applied to the core 135 by any suitable means or methods.
Preferably the coating 137 has a thickness of at least 100
microns.
[0039] With reference to FIGS. 10-13, the bottom liner 150 is shown
therein with the liner members 152 and 154 separated for clarity.
The rear liner member 152 includes an end slot 152B adapted to
receive the tab 110B of the bottom susceptor member 110. The rear
liner member 152 and the front liner member 154 define opposed
semicircular recesses 156B and 156A, respectively. Additionally,
semicircular, downward facing recesses 152C and 154C are formed in
the liner members 152 and 154 along the recesses 156A and 156B.
[0040] With reference to FIG. 13, the rear liner member 152
includes a core 155 and a surrounding layer or coating 157.
Preferably, the coating 157 completely surrounds the core 155. The
core 155 is formed of a material that has high purity, is able to
withstand high temperatures (e.g., having a melting point greater
than 1800.degree. C., has low chemical reactivity, and has
acceptably low electrical resistance). Preferably, the core 155 is
formed of graphite. The core 155 may be formed in the same manner
as described above for the core 115. Preferably, the core 155 has a
thickness of at least 0.15 inch. The core is preferably adapted to
provide a substantially coplanar upper surface with the platter 140
when in use (i.e., the platter 140 is levitated).
[0041] The coating 157 is formed of a material that has low
chemical reactivity. Preferably, the coating 157 is formed of SiC
or a refractory metal carbide that is compatible with SiC. More
preferably, the coating 157 is formed of SIC (preferably dense SiC
that is impervious and has a 0% porosity). The coating 157 may be
applied to the core 155 by any suitable means or methods.
Preferably, the coating, 157 has a thickness of at least about 10
microns. The front liner member 154 is constructed in the same
manner as the rear liner member 152, and has a core (not shown)
corresponding to the core 155 and a coating corresponding to the
coating 157.
[0042] With reference to FIGS. 14-16, the top liner 160 includes
holes 160A adapted to receive the pins 139 or other fasteners. A
wedge portion 162 of the top liner 160 extends with increasing
thickness in the direction of the rear end of the top liner 160.
The wedge portion 162 may serve to gradually decrease the boundary
layer of processing gas flowing through the passage and the outlet
opening 106 to promote transfer of reactants to the substrate
surface from the processing gas.
[0043] Referring to FIG. 16, the top liner 160 includes a core 165
and a surrounding layer or coating 167. Preferably, the coating 167
completely surrounds the core 165. The core 165 may be formed of
the same materials as discussed above with regard to the core 155.
The coating 167 may be formed of the same materials as discussed
above with regard to the coating 157 and may be applied to the core
165 in the manner described above. Preferably, the core 155 has a
nominal thickness of at least about 0.15 inch.
[0044] With reference to FIG. 17, the platter 140 includes a
plurality of recesses on the upper side thereof adapted to hold the
wafers 5. A pin recess 144 for receiving the pin 149 is formed in
the lower side of the platter 140. The platter 140 includes a core
145 and a surrounding layer or coating 147. Preferably, the coating
147 completely surrounds the core 145. The core 145 may be formed
of the same materials as discussed above with regard to the side
wall susceptors 130. The coating 147 may be formed of the same
materials and dimensions as discussed above with regard to the
coating 137, with the same material(s) and dimensions being
preferred, and may be applied to the core 145 in the manner
described above. Alternatively, the platter 140 may be formed of
solid SiC or a solid SiC alloy.
[0045] The insulation covers 16, 18 may be formed of any suitable
material to thermally insulate the housing assembly 100.
Preferably, the insulation covers 16, 18 are formed of a material
having high purity, low chemical reactivity and a thermal
conductivity of less than about 2 W/m/K in vacuum.
[0046] Suitable EMF generators for the EMF generator 11 include a
BIG available from Huettinger Electronic of Germany. The coil 14
and the power supply 12 are electrically coupled such that the
power supply 12 may provide an A/C current through the coil 14 at a
selected frequency or range of frequencies. Preferably, the power
supply 12 is operable to provide a current through the coil 14 at
frequencies of between at least 5 kHz and 1 MHz or a subset of
frequencies in this range. Preferably, the power supply 12 is
operable to provide power in a range of at least 20 kW to 150
kW.
[0047] The housing assembly 100 may be assembled as follows. The
side susceptor members 130 are mounted on the bottom susceptor
member 110. The rear liner member 152 is placed on the bottom
susceptor member 110 such that the tab 110A is received in the slot
152B and the ridge 114 is received in the recess 152C. In this
manner, the liner member 152 is positively located and secured in
place on the bottom susceptor member 110. The front liner member
154 is placed on the bottom susceptor member 110 such that the
ridge 114 is received in the recess 154C. Prior to or following
placement of either or both of the liner members 152, 154, the
platter 140 is placed on the pin 149 over the platter region 112
and in the opening 156. The top liner 160 and the top susceptor
member 120 are mounted on the side susceptor members 130.
[0048] In use, one or more of the substrates 5 are placed in the
passage 102 on the platter 140. The power supply 12 is operated to
provide a power level and frequency of alternating current through
the coil in a known manner to generate an electromagnetic field.
The current frequency is selected such that eddy currents are
generated in the susceptor members 110, 120, 130. The electrical
resistances of the cores 115, 125, 135 and the coatings 117, 127,
137 convert at least portions of the eddy currents to heat such
that heat is generated in the susceptor members 110, 120, 130.
However, the current frequency is selected such that substantially
no eddy currents are generated in the liners 150, 160 or the
platter 140. Rather, substantially all of the power from the coil
14 absorbed by the housing assembly 100 is attenuated by the
susceptor members 110, 120, 130. Preferably, at least 90% of the
power is attenuated by the susceptor members 110, 120, 130, more
preferably at least 95%, and most preferably 100%. Accordingly, no
or only insubstantial heat is inductively generated in the liners
150, 160 or the platter 140.
[0049] The heat or thermal energy inductively generated in the
susceptor members 110, 120, 130 is thermally conducted from the
susceptor members 110, 120, 130 through the liners 150, 160 and the
platter 140 to the passage 102. The substrate 5 is thereby heated
by conduction (through the platter 140), radiation and convection.
Preferably, the substrate 5 is heated to a temperature of between
about 1400 and 1800.degree. C. Notably, and preferably, the platter
140 directly overlies the platter region 112 of the bottom
susceptor member 110 without a portion of the liner 150 being
interposed therebetween. The coatings 157, 167 on the liners 150,
160 may provide thermal breaks from the susceptor members 110, 120
to further promote thermal uniformity.
[0050] In this manner, the internal surfaces of the housing
assembly 100 (i.e. the surfaces in fluid communication with the
passage 102) are maintained at a more spatially uniform temperature
so that the thermal gradients in the vicinity of the substrate are
reduced. Restated, a more isothermal environment may be created in
the passage 102 for the substrate 5 such that the temperature of
the portion of the housing assembly 100 in contact with the
substrate 5 (i.e., the platter 140) is at substantially the same
temperature as the other surfaces defining the passage 102 (i.e.,
the interior surfaces of the liners 150, 160 and the side susceptor
members 130). The substrate 5 may therefore itself be substantially
the same temperature as the surfaces defining the passage 102. As a
result, the aforementioned problems associated with undesirably
large thermal gradients may be reduced. For example, the formation
of loose deposits may be eliminated or reduced. The process (e.g.,
an epitaxy process) may be more accurately controlled.
[0051] During the reacting process, the processing gas IG (FIG. 2)
may be flowed into the passage 102 through the opening 104. The
processing gas IG may include precursor gases such as silane
(SiH.sub.4) and propane (C.sub.3H.sub.8) introduced with and
transported by a carrier of purified hydrogen gas (H.sub.2). The
processing gas IG passes through the passage 102. As the processing
gas IG passes through the hot zone generated by the EMF generator
11, SiC deposition reactions take place on the substrate 5. The
remainder OG of the processing gas exits the passage 102 through
the opening 106. Preferably, the processing gas IG is flowed
through the passage 102 at a rate of at least 10 slpm.
[0052] It may be desirable to remove and replace the platter 140.
For example, it may be necessary to remove the substrate or
substrates 5 following processing and replace them with new
substrates for processing. Also, it may be desirable to remove the
platter 140 for cleaning or replacement with a new platter. The
platter may be conveniently removed by first removing the front
liner member 154 and then removing the platter 140. It may also be
desirable to remove either or both of the liner members 152, 154.
Each of these procedures may be executed without disassembling the
remainder of the housing assembly 100 or removing the housing
assembly 100 from the reactor assembly 10.
[0053] The housing assembly 100 may provide for a more efficient,
convenient and durable heating device, particularly where TaC is
used for the coatings 117, 127 and SiC is used for the coatings
130, 140, 150, 160. The TaC coatings 117, 127, 137 may serve to
reduce thermal radiation losses and prevent or reduce undesirable
sublimation of the SiC coatings. The TaC coating in the platter
region 112 of the bottom susceptor 110 may provide a more durable
platform for the rotating platter 140. The provision of the SiC
coatings in fluid communication with the passage 102 and in the
vicinity of the substrate take advantage of the adherent nature of
parasitic SiC deposits to the SiC coatings and the chemical,
thermal, mechanical, and structural similarity of the SiC coatings
and the SiC substrate 5. The SiC coatings 137 on the side susceptor
members 130 may assist in reducing the heating of the side
susceptors due to induction heating.
[0054] The provision of liners 150, 160 separately formed from the
susceptor members 110, 120, 130 may allow for extension of the
service life of the housing assembly 100 as well as reductions in
cost of use and downtime. The liners 150, 160 may be
cost-effectively replaced when they reach the end of their useful
service lives without requiring replacement of the remainder of the
housing assembly 100. Moreover, the liner members 152, 154 can be
removed for cleaning (e.g., to scrape away parasitic deposits)
without requiring removal of the housing assembly from the reactor
assembly 10 or disassembly of the remainder of the housing assembly
100.
[0055] The design (e.g., dimensions, materials, and/or placement)
of the liner or liners may be selected, modified or interchanged to
shape or control the temperature gradient in the processing
chamber. For example, additional liners may be positioned along the
side susceptor members 130 or one or more of the liners may vary in
thickness or material. The liners may be integrated (e.g., as a
unitary sleeve). The liners may be integrally formed with the
susceptor member or members. Preferably, the liner or liners will
include an opening corresponding to the opening 156 positioned to
receive the platter.
[0056] Liners may be selected or interchanged to obtain desired gas
flow characteristics. In particular, the top liner 160 may be
removed and replaced with a top liner having a differently shaped
wedge portion 162 or having no wedge portion.
[0057] While certain embodiments have been described above, it will
be appreciated that various modifications may be made in accordance
with the invention. For example, the processing chamber may be
closed at one or both ends rather than providing a through passage
102. Housing assemblies and heating devices according to the
invention may be used for other types of processes and material
systems, as well as in other types of deposition systems. In
particular, the housing assemblies and heating devices according to
the invention may be used for annealing processes. Articles other
than semiconductor substrates may be processed.
[0058] In other embodiments, end insulation may be placed at either
or both ends of the housing assembly 100. The end insulation, if
present, may be shaped like a short cylinder of diameter to match
the diameter of the covers 16, 18. Passages through the end
insulation may be provided to permit the process gas IG to flow
freely through the processing chamber. The passages in the end
insulations may be provided with protection liners, preferably made
of silicon carbide coated graphite, that separate the process gas
IG from the end insulation material which may contaminate the
process gas.
[0059] While preferred embodiments have been described with
reference to "top", "bottom" and the like, other orientations and
configurations may be employed in accordance with the
invention.
[0060] The foregoing is illustrative of the present invention and
is not to be construed as limiting thereof. Although a few
exemplary embodiments of this invention have been described, those
skilled in the art will readily appreciate that many modifications
are possible in the exemplary embodiments without materially
departing from the novel teachings and advantages of this
invention. Accordingly, all such modifications are intended to be
included within the scope of this invention. Therefore, it is to be
understood that the foregoing is illustrative of the present
invention and is not to be construed as limited to the specific
embodiments disclosed, and that modifications to the disclosed
embodiments, as well as other embodiments, are intended to be
included within the scope of the invention.
* * * * *