U.S. patent application number 14/828304 was filed with the patent office on 2017-02-23 for susceptor and substrate processing apparatus.
This patent application is currently assigned to ASM IP HOLDING B.V.. The applicant listed for this patent is ASM IP HOLDING B.V.. Invention is credited to Yukihiro MORI.
Application Number | 20170051402 14/828304 |
Document ID | / |
Family ID | 58157803 |
Filed Date | 2017-02-23 |
United States Patent
Application |
20170051402 |
Kind Code |
A1 |
MORI; Yukihiro |
February 23, 2017 |
SUSCEPTOR AND SUBSTRATE PROCESSING APPARATUS
Abstract
A susceptor includes a plate part, a first heater for heating a
first portion of the plate part, a second heater for heating a
second portion of the plate part, and a heat insulating portion for
thermally insulating the first portion and the second portion from
each other on an upper surface side of the plate part.
Inventors: |
MORI; Yukihiro; (Tokyo,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASM IP HOLDING B.V. |
Almere |
|
NL |
|
|
Assignee: |
ASM IP HOLDING B.V.
Almere
NL
|
Family ID: |
58157803 |
Appl. No.: |
14/828304 |
Filed: |
August 17, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/509 20130101;
H01J 37/32715 20130101; C23C 16/4412 20130101; H01J 2237/3321
20130101; C23C 16/46 20130101; H01J 2237/334 20130101; H01L 21/6719
20130101; C23C 16/4583 20130101; C23C 16/50 20130101; H01J 37/32009
20130101; C23C 16/45544 20130101; C23C 16/52 20130101; H01L
21/67248 20130101; H01L 21/67103 20130101; H01L 21/67109 20130101;
C23C 16/463 20130101; H01J 37/32724 20130101; H01J 37/3244
20130101 |
International
Class: |
C23C 16/44 20060101
C23C016/44; C23C 16/455 20060101 C23C016/455; C23C 16/458 20060101
C23C016/458; C23C 16/46 20060101 C23C016/46 |
Claims
1. A susceptor comprising: a plate part; a first heater for heating
a first portion of the plate part; a second heater for heating a
second portion of the plate part; and a heat insulating portion for
thermally insulating the first portion and the second portion from
each other on an upper surface side of the plate part.
2. The susceptor according to claim 1, wherein the heat insulating
portion is a grooved portion provided in the plate part on the
upper surface side.
3. The susceptor according to claim 1, wherein the second portion
surrounds the first portion as viewed in plan.
4. The susceptor according to claim 3, further comprising: a third
portion formed as a portion of the plate part, the third portion
surrounding the second portion as viewed in plan; a third heater
for heating the third portion; and an outer heat insulating portion
for thermally insulating the second portion and the third portion
from each other on the upper surface side of the plate part.
5. The susceptor according to claim 1, wherein each of the first
portion and the second portion is formed in sectoral form as viewed
in plan.
6. The susceptor according to claim 1, wherein the first portion is
a portion including an outer edge of the plate part, and the second
portion is a portion including an outer edge of the plate part.
7. The susceptor according to claim 3, further comprising: a
plurality of third portions formed as part of the plate part, the
third portions as a whole surrounding the second portion as viewed
in plan; a plurality of third heaters provided in the plurality of
third portions in a one-to-one relationship; an outer heat
insulating portion for thermally insulating the second portion and
the plurality of third portions from each other on the upper
surface side of the plate part; and outer-edge-side heat insulating
portions for thermally insulating the plurality of third portions
from each other on the upper surface side of the plate part.
8. The susceptor according to claim 2, further comprising: a first
closing part provided on the first portion to close part of a
groove in the grooved portion without contacting the second
portion; and a second closing part provided on the second portion
to close part of a groove in the grooved portion without contacting
the first portion and the first closing part.
9. The susceptor according to claim 2, wherein the first portion
and the second portion are separate parts; a projection is provided
on a side surface of the first portion, the second portion being
put on the projection; and the grooved portion is formed by a side
surface of the first portion, an upper surface of the projection
and a side surface of the second portion.
10. The susceptor according to claim 1, further comprising a
cooling member attached to the plate part.
11. The susceptor according to claim 2, further comprising a
cooling member attached to the plate part, wherein the cooling
member is attached to the plate part right below the grooved
portion.
12. The susceptor according to claim 1, further comprising an
electrostatic chuck.
13. The susceptor according to claim 1, wherein the heat insulating
portion is a cooling device provided in the plate part.
14. A substrate processing apparatus comprising: a susceptor having
a plate part, a first heater for heating a first portion of the
plate part, a second heater for heating a second portion of the
plate part, and a heat insulating portion for thermally insulating
the first portion and the second portion from each other on an
upper surface side of the plate part; a chamber in which the
susceptor is housed; and an gas exhaust part attached to a side
surface of the chamber, wherein the first portion is a portion
including an outer edge of the plate part; the second portion is a
portion including an outer edge of the plate part; and the gas
exhaust part and the first portion are opposed to each other as
viewed in plan.
15. A substrate processing apparatus comprising: a susceptor having
a plate part, a first heater for heating a first portion of the
plate part, a second heater for heating a second portion of the
plate part, and a heat insulating portion for thermally insulating
the first portion and the second portion from each other on an
upper surface side of the plate part; a chamber in which the
susceptor is housed; and a gate valve attached to a side surface of
the chamber, wherein the first portion is a portion including an
outer edge of the plate part; the second portion is a portion
including an outer edge of the plate part; and the gate valve and
the second portion are opposed to each other as viewed in plan.
Description
BACKGROUND OF THE INVENTION
[0001] Field of the Invention
[0002] The present invention relates to a susceptor supporting a
substrate and to a substrate processing apparatus provided with a
susceptor.
[0003] Background Art
[0004] U.S. Pat. No. 6,469,283B1 discloses an arrangement for
applying 100% of electric power to one region of a substrate
supporting table having a plurality of regions and applying 50% of
electric power to the other regions.
[0005] In some semiconductor or liquid crystal manufacturing
processes, the temperature of a substrate is intentionally made
uneven when the substrate is processed. For example, in some cases,
film forming is performed on a substrate while the temperature of
the substrate is made uneven, thereby making nonuniform the film
thickness of a thin film formed on the substrate or making the film
quality nonuniform. From the viewpoint of realizing such
processing, it is preferable to create a definite temperature
difference between certain different places in the substrate.
[0006] While the substrate supporting table disclosed in U.S. Pat.
No. 6,469,283B1 is capable of separately heating the plurality of
regions, the plurality of regions join one to another in the upper
surface of the substrate supporting table. The substrate supporting
table (susceptor) is generally made of a material having good heat
conductivity, e.g., aluminum, aluminum nitride (AlN), carbon or
silicon carbide (SiC). In the substrate supporting table disclosed
in U.S. Pat. No. 6,469,283B1, therefore, transfer of heat from one
zone to another is active and a definite temperature difference
cannot be created between certain different places in a
substrate.
SUMMARY OF THE INVENTION
[0007] In view of the above-described problem, an object of the
present invention is to provide a susceptor capable of creating a
definite temperature difference in a substrate and a substrate
processing apparatus provided with the susceptor.
[0008] The features and advantages of the present invention may be
summarized as follows.
[0009] According to one aspect of the present invention, a
susceptor includes a plate part, a first heater for heating a first
portion of the plate part, a second heater for heating a second
portion of the plate part, and a heat insulating portion for
thermally insulating the first portion and the second portion from
each other on an upper surface side of the plate part.
[0010] According to another aspect of the present invention, a
substrate processing apparatus includes a susceptor having a plate
part, a first heater for heating a first portion of the plate part,
a second heater for heating a second portion of the plate part, and
a heat insulating portion for thermally insulating the first
portion and the second portion from each other on an upper surface
side of the plate part, a chamber in which the susceptor is housed,
and an gas exhaust part attached to a side surface of the chamber,
The first portion is a portion including an outer edge of the plate
part, the second portion is a portion including an outer edge of
the plate part, and the gas exhaust part and the first portion are
opposed to each other as viewed in plan.
[0011] According to another aspect of the present invention, a
substrate processing apparatus includes a susceptor having a plate
part, a first heater for heating a first portion of the plate part,
a second heater for heating a second portion of the plate part, and
a heat insulating portion for thermally insulating the first
portion and the second portion from each other on an upper surface
side of the plate part, a chamber in which the susceptor is housed,
and a gate valve attached to a side surface of the chamber. The
first portion is a portion including an outer edge of the plate
part, the second portion is a portion including an outer edge of
the plate part, and the gate valve and the second portion are
opposed to each other as viewed in plan.
[0012] Other and further objects, features and advantages of the
invention will appear more fully from the following
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a sectional view of a substrate processing
apparatus according to a first embodiment;
[0014] FIG. 2 is a plan view of the plate part;
[0015] FIG. 3 is a diagram showing a method of controlling the
temperature of the susceptor;
[0016] FIG. 4 is a diagram showing a substrate placed on the plate
part;
[0017] FIG. 5 is a graph showing the temperature of the susceptor
surface;
[0018] FIG. 6 is a plan view of the susceptor according to the
second embodiment;
[0019] FIG. 7 is a plan view of the substrate processing apparatus
according to the third embodiment;
[0020] FIG. 8 is a plan view of the substrate processing apparatus
according to the fourth embodiment;
[0021] FIG. 9 is a sectional view of a susceptor and other members
according to the fifth embodiment;
[0022] FIG. 10 is a sectional view of a susceptor according to the
sixth embodiment;
[0023] FIG. 11 is a sectional view of a susceptor and other members
according to the seventh embodiment; and
[0024] FIG. 12 is a sectional view of a susceptor according to the
eighth embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] A susceptor and a substrate processing apparatus according
to an embodiment of the present invention will be described with
reference to the drawings. Components identical or corresponding to
each other are assigned the same reference numerals and repeated
description of them is omitted in some cases.
First Embodiment
[0026] FIG. 1 is a sectional view of a substrate processing
apparatus 10 according to a first embodiment of the present
invention. The substrate processing apparatus 10 is constructed as
a film forming apparatus for performing, for example, plasma
enhanced atomic layer deposition (PEALD) on a substrate. The
substrate processing apparatus 10 has a chamber (reactor chamber)
12. A radio frequency (RF) electrode 14 to which RF power is
applied is provided in the chamber 12. Slits 14a are provided in
the RF electrode 14.
[0027] A susceptor 15 is provided in the chamber 12 so as to be
opposed to the RF electrode 14. The susceptor 15 includes a plate
part 16 and a slide shaft 18 supporting the plate part 16. The RF
electrode 14 and the plate part 16 form a parallel plate
structure.
[0028] A gas supply part 22 is connected to the RF electrode 14
with an insulating part 20 interposed therebetween. The gas supply
part 22 is a part through which a material gas is supplied to a
space between the RF electrode 14 and the susceptor 15. An exhaust
duct 30 is provided between the RF electrode 14 and the chamber 12.
The exhaust duct 30 is formed, for example, of a ceramic. An O-ring
32 suitably compressed is provided between the exhaust duct 30 and
the RF electrode 14. An O-ring 34 suitably compressed is provided
between the exhaust duct 30 and the chamber 12.
[0029] The exhaust duct 30 is formed into an annular shape as
viewed in plan, such that it surrounds the plate part 16. An
annular passage 30b surrounding a processing space 17 on the plate
part 16 is provided by the exhaust duct 30. In the exhaust duct 30,
an annular slit 30a through which a gas supplied into the
processing space 17 is led into the annular passage 30b and an
exhaust port 30c through which the gas in the annular passage 30b
is discharged to the outside are formed.
[0030] The exhaust port 30c connects with a gas exhaust part 40
provided on a side surface of the chamber 12. The gas exhaust part
40 is provided to exhaust a material gas used for film forming. A
valve 42 and a vacuum pump 44 are connected to the gas exhaust part
40. The pressure in the chamber 12 can be freely controlled by
adjusting the exhaust rate with the valve 42 and the vacuum pump
44.
[0031] The thickness of the plate part 16 is, for example, 33 mm.
It is preferable that the plate part 16 be formed of a material
such as aluminum having good heat conductivity. In the plate part
16, a first heater 50 and a second heater 52 are embedded. The
first heater 50 and the second heater 52 are each a resistance
heater for example. A heat insulating portion 16A is provided
between the first heater 50 and the second heater 52. The heat
insulating portion 16A is a grooved portion in which a groove (gap)
is provided. For the heat insulating portion 16A, a groove is
provided in the upper surface of the plate part 16.
[0032] FIG. 2 is a plan view of the plate part 16. The diameter of
the plate part 16 is set to, for example, 325 mm to support a
substrate having a diameter of 300 mm. The plate part 16 has a
central portion as a first portion 16a. The first heater 50 is
provided in annular form in the first portion 16a. The first heater
50 is a heater for heating the first portion 16a. The first heater
50 is indicated by a broken line. The first heater 50 has a center
diameter of 180 mm for example. The center diameter is a value
computed by dividing the sum of the outside diameter and the inside
diameter by 2.
[0033] The plate part 16 has an outer portion as a second portion
16b. The second heater 52 is provided in annular form in the second
portion 16b. The second portion 16b surrounds the first portion 16a
as viewed in plan. The second heater 52 is a heater for heating the
second portion 16b. The second heater 52 is indicated by a broken
line. The second heater 52 has a center diameter of 280 mm for
example. The first heater 50 and the second heater 52 are provided
concentrically with each other.
[0034] The heat insulating portion 16A is formed in annular form as
viewed in plan. The heat insulating portion 16A is formed by a side
surface of the first portion 16a, a side surface of the second
portion 16b distanced from the side surface of the first portion
16a and a bottom surface connecting these side surfaces. A groove
16A' is provided by the heat insulating portion 16A. The heat
insulating portion 16A functions as a heat insulating portion
thermally insulating the first portion 16a and the second portion
16b from each other on the upper surface side of the plate part 16.
The size of the groove 16' is, for example, a width of 1.5 mm, a
depth of 23 mm and a center diameter of 247.5 mm.
[0035] FIG. 3 is a diagram showing a method of controlling the
temperature of the susceptor. The first heater 50 is connected to a
heater controller 60 by wiring 50a. The second heater 52 is
connected to the heater controller 60 by wiring 52a. The heater
controller may be divided into two controllers for respectively
controlling the first heater 50 and the second heater 52.
[0036] Wirings 50a and 52b are passed through the slide shaft 18
and extend to the outside from the lower end of the slide shaft 18.
Therefore, the wirings 50a and 50b are not exposed to the interior
of the chamber 12. If the wirings 50a and 50b are led from a side
surface of the plate part 16 to the outside, the wirings 50a and
50b are exposed to the interior of the chamber 12 and subjected to
plasma. Therefore, such a wiring layout is not preferable. Also, if
the wirings 50a and 50b are led to the outside from a side surface
of the plate part 16, there is a risk of the wirings 50a and 50b
being damaged when the susceptor 15 is vertically moved. It is,
therefore, preferable to lead out the wirings 50a and 50b from the
lower end of the slide shaft 18.
[0037] A process module controller (PMC) 62 is connected to the
heater controller 60. A unique platform controller (UPC) 64 is
connected to the PMC 62. A temperature measuring part 65 for
measuring the temperature of the susceptor 15 is attached to the
plate part 16. The temperature measuring part 65 is, for example, a
thermocouple. Information on the temperature measured with the
temperature measuring part 65 is transmitted to a temperature
controller 66. This information is used for control of the
temperature of the susceptor 15.
[0038] A method of processing a substrate with the substrate
processing apparatus 10 having the above-described susceptor 15
will be described. The vacuum pump 44 is constantly operated to
maintain a vacuum in the chamber 12. A substrate to be processed is
first placed on the plate part 16. FIG. 4 is a diagram showing a
substrate 70 placed on the plate part 16. The substrate 70 is
placed both on the first portion 16a and on the second portion 16b.
The portion of the substrate 70 on the first portion 16a is
referred as a substrate central portion 70A. The portion of the
substrate 70 on the second portion 16b is referred to as a
substrate marginal portion 70B. In the case of a substrate having a
film such as SiO.sub.2 film attached to its back surface, the film
absorbs water and there is a possibility of the substrate sliding
when placed on the heated susceptor. It is thus preferable to
provide a shallow groove for receiving the substrate 70 in the
upper surface of the plate part 16 to ensure that the substrate
does not slide on the plate part 16. A small projection may
alternatively be provided on the upper surface of the plate part
16, and the side surface of the substrate may be caused to abut
against the projection in order to prevent the substrate from
sliding.
[0039] Subsequently, the substrate 70 is heated. In a recipe in
which conditions for processing the substrate 70 are described, a
target temperature of the first portion 16a and a target
temperature of the second portion 16b are set. The heater
controller 60 energizes the first heater 50 and the second heater
52 based on this setting so that the first portion 16a and the
second portion 16b has the target temperatures. For example, the
first portion 16a has a temperature of 300.degree. C. and the
second portion 16b has a temperature of 305.degree. C.
[0040] At this time the groove 16A' functions as a heat insulating
layer because the groove 16A' has a vacuum therein. With the heat
insulating portion 16A (groove 16A'), transfer of heat between the
first portion 16a and the second portion 16b can be limited on the
upper surface side of the plate part 16. That is, since the first
portion 16a and the second portion 16b are thermally insulated from
each other on the upper surface side of the plate part 16 by the
heat insulating portion 16A, a definite temperature difference can
be created on the upper surface side of the plate part 16.
[0041] FIG. 5 is a graph showing the temperature of the susceptor
surface. A solid line indicates the surface temperature of the
plate part 16 according to the first embodiment of the present
invention. More specifically, the solid line indicates a
temperature distribution along line A-A' in FIG. 2. For the first
portion 16a, the temperature in accordance with the setting in the
recipe (300.degree. C.) was substantially realized. Also for the
second portion 16b, the temperature in accordance with the setting
in the recipe (305.degree. C.) was substantially realized.
Moreover, the provision of the heat insulating portion 16A for
thermally insulating the first portion 16a and the second portion
16b on the upper surface side of the plate part enabled creating a
definite temperature difference between the first portion 16a and
the second portion 16b.
[0042] On the other hand, a broken line in FIG. 5 indicates the
temperature of a susceptor surface according to a comparative
example. The susceptor according to the comparative example is
generally the same as the susceptor according to the first
embodiment of the present invention but differs in that the heat
insulating portion is not provided. Since no heat insulating
portion exists in the plate part of the susceptor according to the
comparative example, heat transfers between the first portion
(central portion) and the second portion (marginal portion) on the
upper surface side of the plate part. Therefore, the temperature
distribution in the susceptor surface in the comparative example is
such that the temperature increases gradually along a direction
from the center toward the outer edge of the plate part. That is, a
definite temperature difference cannot be created in the plate
part.
[0043] The definite temperature difference created in the plate
part 16 according to the first embodiment is reflected in the
temperature of the substrate 70 placed on the plate part 16. That
is, in the substrate 70 shown in FIG. 4, the temperature of the
substrate central portion 70A is 300.degree. C. and the temperature
of the substrate marginal portion 70B is 305.degree. C. After the
substrate 70 is thus set to the predetermined temperatures, a
material gas is supplied into the chamber 12 to perform plasma film
forming on the substrate 70.
[0044] In ordinary substrate processing, a sequence of process
steps consisting of forming a film on the substrate, forming a
pattern by exposure and development, and removing unnecessary
portions by etching are repeatedly executed. Ideal substrate
processing is a process in which a film is formed with no in-plane
nonuniformity, a pattern is formed with no in-plane nonuniformity,
and etching is performed with no in-plane nonuniformity. For
example, in the etching step, there is a possibility of in-plane
nonuniformity of the amount of etching. In such a case, the
in-plane nonuniformity should be inhibited by adjusting conditions
for the etching step. In some cases, however, such adjustment is
impossible or difficult to perform.
[0045] In some cases, therefore, a demand is made for intentionally
making nonuniform the film quality or film thickness of the film
formed in the film forming step in order to absorb an in-plane
nonuniformity of the amount of etching. For example, in some cases,
if the amount of etching on the outer edge side of the substrate is
relatively increased by etching, film forming is performed so that
the thickness is increased on the substrate outer edge side.
[0046] The susceptor and the substrate processing apparatus
according to the first embodiment of the present invention are
capable of creating a definite temperature difference in the
substrate, as described above, and are, therefore, suitable for
intentionally making the film thickness or film quality of the film
nonuniform. Consequently, a nonuniformity as a result of the entire
process can be removed by forming a film having any desirable
nonuniformity to absorb an in-plane nonuniformity other than a
nonuniformity in the film forming step. That is, an in-plane
nonuniformity at the end of the process can be limited.
[0047] The distribution of the film thickness of the film to be
formed and the distribution of the film quality are set as desired
according to conditions needed from steps other than the film
forming step. For example, a film thicker (or thinner) than a film
on the substrate central portion is formed on the substrate
marginal portion, or a film formed on the substrate marginal
portion is made harder (or softer) than a film formed on the
substrate central portion.
[0048] In the case of plasma film forming, the electric field
intensity is increased at the substrate central portion and is
reduced at the substrate marginal portion due to the contribution
of the chamber. Also, in plasma film forming, the film thickness on
a portion at which the substrate temperature is low ordinarily
becomes higher than that of a portion at which the substrate
temperature is high. A definite temperature difference is created
in the substrate by comprehensively considering factors
contributing to the in-plane distribution of the film thickness or
film quality to form a film having an in-plane nonuniformity which
meets a demand.
[0049] The susceptor 15 and the substrate processing apparatus 10
according to the first embodiment of the present invention can be
variously modified. Determination as to which portion of the film
is to be made harder (or softer) or which portion is to be made
thicker (or thinner) is suitably made to meet a demand from a step
other than the film forming step. The susceptor and the substrate
processing apparatus according to the present invention can be
constructed not only as the film forming apparatus but also as an
etcher. The film forming apparatus and an etcher have a commonality
in being a plasma process in a vacuum.
[0050] From the viewpoint of equalization between the temperature
distribution realized in the plate part 16 and the temperature
distribution in the substrate 70, it is preferable that the
substrate 70 be in close contact with the plate part 16. It is,
therefore, preferable to maintain the substrate 70 in close contact
with the plate part 16 with an electrostatic chuck provided on the
plate part 16.
[0051] The change in temperature of the susceptor 15 due to contact
between the substrate 70 and the susceptor 15 is small because the
heat capacity of the susceptor 15 is larger than that of the
substrate 70.
[0052] In the recipe, setting of a temperature difference between
the first portion 16a and the second portion 16b may be made
instead of setting of both target temperatures of the two
portions.
[0053] For example, target temperatures of the first and second
portions 16a and 16b may be set in such a manner that the target
temperature of the first portion 16a is set in the recipe and the
target temperature of the second portion 16b is defined as the
result of addition of a predetermined temperature (e.g., 50.degree.
C.) to the target temperature of the first portion 16a or
subtraction of a predetermined temperature from the target
temperature of the first portion 16a.
[0054] The pattern of the heat insulating portion 16A can be
changed as desired according to the required temperature
distribution in the substrate. The size of the groove 16A' and
other values shown in the first embodiment is only an example and
can be changed as desired. Modifications thus made can also be
applied as desired to susceptors and substrate processing
apparatuses according to other embodiments described below. The
susceptors and substrate processing apparatuses according to the
embodiments described below have a number of commonalities with
those in the first embodiment and will therefore be described
mainly with respect to points of difference from the first
embodiment.
Second Embodiment
[0055] FIG. 6 is a plan view of the susceptor according to the
second embodiment. A third portion 16c is formed as a portion of
the plate part 16. The third portion 16c surrounds the second
portion 16b as viewed in plan. A third heater 80 for heating the
third portion 16c is embedded in the third portion 16c. The third
heater 80 is indicated by a broken line. The first heater 50, the
second heater 52 and the third heater 80 are provided
concentrically with each other.
[0056] An outer heat insulating portion 16B is provided in the
plate part 16 on the upper surface side. The outer heat insulating
portion 16B is formed by a side surface of the second portion 16b,
a side surface of the third portion 16c distanced from the side
surface of the second portion 16b and a bottom surface connecting
these side surfaces. The outer heat insulating portion 16B provides
a groove 16B' which functions as a heat insulating layer. The
groove 16B' thermally insulates the second portion 16b and the
third portion 16c from each other on the upper surface side of the
plate part 16.
[0057] With the susceptor according to the second embodiment of the
present invention, the temperatures of the first portion 16a, the
second portion 16b and the third portion 16c can be independently
set to desired temperatures. The degree of freedom of the
temperature distribution in the substrate can therefore be improved
in comparison with that in the susceptor according to the first
embodiment in which the plate part is divided into two on the upper
surface side for temperature control.
Third Embodiment
[0058] FIG. 7 is a plan view of the substrate processing apparatus
according to the third embodiment. Of the chamber 12, only the side
wall portion is illustrated so that the interior of the chamber 12
can be seen. In the chamber 12, the susceptor is housed. FIG. 7
shows the plate part 16. A gas exhaust part 40 is attached to a
side surface of the chamber 12 for the purpose of evacuating the
chamber 12 and exhausting a material gas supplied into the chamber
12. A gate valve 102 is attached to a side surface of the chamber
12 for the purpose of putting a substrate in the chamber 12 and
taking out the substrate from the chamber 12. A wafer handling
chamber 104 is connected to the gate valve 102.
[0059] The plate part 16 of the susceptor has a first portion 16d,
a second portion 16e, a third portion 16f and a fourth portion 16g.
Each of the first to forth portions 16d, 16e, 16f, and 16g is
sectoral as viewed in plan. The first to forth portions 16d, 16e,
16f, and 16g are portions including the outer edge of the plate
part 16. The gas exhaust part 40 and the first portion 16d are
opposed to each other as viewed in plan. The gate valve 102 and the
second portion 16e are opposed to each other as viewed in plan.
Thus, the first portion 16d is a region in the plate part 16 closer
to the gas exhaust part 40, while the second portion 16e is a
region in the plate part 16 closer to the gate valve 102.
[0060] In the plate part 16, heat insulating portions 16C and 16D
are formed, which are grooved portions. For the heat insulating
portion 16C, a groove 16C' is provided between the first portion
16d and the fourth portion 16g and between the second portion 16e
and the third portion 16f. For the heat insulating portion 16D, a
groove 16D' is provided between the first portion 16d and the third
portion 16f and between the second portion 16e and the fourth
portion 16g.
[0061] For the heat insulating portions 16C and 16D, grooves
forming a crisscross pattern are provided in the plate part 16. The
width and depth of the grooves 16C' and 16D', not particularly
specified, are substantially the same as those of the grooves
described in the description of the first embodiment.
[0062] A first heater 110 for heating the first portion 16d is
embedded in the first portion 16d. A second heater 112 for heating
the second portion 16e is embedded in the second portion 16e. A
third heater 114 for heating the third portion 16f is embedded in
the third portion 16f. A fourth heater 116 for heating the fourth
portion 16g is embedded in the fourth portion 16g. The first to
fourth heaters 110, 112, 114, and 116 are individually controlled
with the heater controller. Under the control of the heater
controller, therefore, the first to fourth portions 16d, 16e, 16f,
and 16g can have different temperatures. The first to fourth
portions 16d, 16e, 16f, and 16g are thermally separated from each
other on the upper surface side of the plate part 16 by the heat
insulating portions 16C and 16D, thus enabling creating definite
temperature differences in the substrate.
[0063] When a gas in the chamber 12 is exhausted (evacuated), the
interior of the chamber 12 is not uniformly evacuated. The pressure
in a place near the gas exhaust part 40 is lower than the pressure
in a place remote from the gas exhaust part 40. In an area where
the pressure is low, the gas stay time (the time period during
which one molecule stays in plasma) is reduced. In many cases of
processing in film forming apparatuses or etchers, therefore, the
film forming speed is reduced in a place near the gas exhaust part
40 in the film forming apparatus, or the etching speed is reduced
in a place near the gas exhaust part 40 in the etcher.
[0064] The susceptor 15 and the chamber 12 are at the same
potential (ground). At the time of plasma generation, main
discharge from the RF electrode 14 to the closest electrode (the
plate part 16 of the susceptor 15) occurs. However, discharge from
the RF electrode 14 to portions including the chambers not
originally supposed to function as an electrode also occurs. From
the viewpoint of preventing film forming conditions becoming uneven
in the substrate plane, it is preferable that the chamber 12
surrounds the RF electrode 14, and that the distance from the RF
electrode 14 are uniform with respect to all directions. In
actuality, however, the distance from the RF electrode 14 to the
electrodes at the ground potential and the electrode shapes are not
uniform because of the gate valve 102. That is, the way of
spreading of plasma in the vicinity of the gate valve 102 and the
way of spreading in a place remote from the gate valve 102 are
different from each other.
[0065] Thus, film forming conditions in an area near the gas
exhaust part 40 and film forming conditions in an area remote from
the gas exhaust part 40 are different from each other and film
forming conditions in an area near the gate valve 102 and film
forming conditions in an area remote from the gate valve 102 are
also different from each other. That is, even between two points at
the same distance from the substrate center, the film forming
conditions are changed depending on the distances of the points
from the gas exhaust part 40 and the gate valve 102.
[0066] Therefore, the susceptor according to the third embodiment
of the present invention is designed so that the first portion 16d
opposed to the gas exhaust part 40 can be independently
temperature-controlled. The temperature of the first portion 16d is
set in consideration of the specialty of film forming conditions at
the first portion 16d, thus enabling control of the film thickness
and film quality of a film formed on the substrate on the first
portion 16d.
[0067] Further, the susceptor is designed so that the second
portion 16e opposed to the gate valve 102 can be independently
temperature-controlled. The temperature of the second portion 16e
is set in consideration of the specialty of film forming conditions
at the second portion 16e, thus enabling control of the film
thickness and film quality of a film formed on the substrate on the
second portion 16e.
[0068] In a case where the influence of the existence of the gate
valve 102 on the film forming quality is small, opposing the gas
exhaust part 40 and the first portion 16d suffices and the second
portion 16e is not necessarily opposed to the gate valve 102. Also,
in a case where the influence of the existence of the gas exhaust
part 40 on the film forming quality is small, opposing the gate
valve 102 and the second portion 16e suffices and the first portion
16d is not necessarily opposed to the gas exhaust part 40. The
positions of the gate valve 102 and the gas exhaust part 40 are not
necessarily in a symmetric relationship with each other. Also, the
plate part 16 may be divided into three portions or five or more
portions by heat insulating portions.
Fourth Embodiment
[0069] FIG. 8 is a plan view of the substrate processing apparatus
according to the fourth embodiment. The first portion 16a, the
second portion 16b, and heat insulating portion 16A and the outer
heat insulating portion 16B are provided in the same way as those
of the plate part 16 in the second embodiment (FIG. 6). In the
fourth embodiment of the present invention, the third portion 16c
in the second embodiment is divided into four. That is, as shown in
FIG. 8, four third portions 16h, 16i, 16j, and 16k are provided as
portions of the plate part 16. The four third portions 161h, 16i,
16j, and 16k as a whole surround the second portion 16b as viewed
in plan. The third portion 16h is opposed to the gas exhaust part
40. The third portion 16j is opposed to the gate valve 102.
[0070] A third heater 124 for heating the third portion 16h is
embedded in the third portion 16h. A third heater 126 for heating
the third portion 16i is embedded in the third portion 16i. A third
heater 128 for heating the third portion 16j is embedded in the
third portion 16j. A third heater 130 for heating the third portion
16k is embedded in the third portion 16k. Thus, one third heater is
provided in each of the plurality of third portions. The four third
heaters 124, 126, 128, and 130 are individually controlled by the
heater controller. The four third portions 16h, 16i, 16j, and 16k
can therefore be controlled by the heater controller to have
different temperatures.
[0071] The outer heat insulating portion 16B, which is a grooved
portion, is formed in the plate part. The outer heat insulating
portion 16B thermally insulates the second portion 16b and the
plurality of third portions 16h, 16i, 16j, and 16k from each other
on the upper surface side of the plate part. Further,
outer-edge-side heat insulating portions 16G, 16H, 16I, and 16J,
which are grooved portions, are formed in the plate part. The
outer-edge-side heat insulating portions 16G, 16H, 16I, and 16J
thermally insulate the plurality of third portions from each other
on the upper surface side of the plate part. The first portion 16a,
the second portion 16b, and the plurality of third portions 16h,
16i, 16j, and 16k are thermally separated from each other on the
upper surface side of the plate part by the heat insulating portion
16A, the outer heat insulating portion 16B and the outer-edge-side
heat insulating portions 16G, 16H, 16I, and 16J, thus enabling
creating definite temperature differences in the substrate.
[0072] In some cases, the influence of the existence of the gas
exhaust part 40 on film forming conditions are particularly large
at an edge portion of the substrate near the gas exhaust part 40
and is small at a central portion of the substrate. In the fourth
embodiment of the present invention, therefore, independent
temperature control of the third portion 16h opposed to the gas
exhaust part 40 at an outer edge portion of the plate part is
enabled. The temperature of the third portion 16h is set in
consideration of the specialty of film forming conditions at the
third portion 16h, thus enabling control of the film thickness and
film quality of a film formed on the substrate on the third portion
16h.
[0073] Also, in some cases, the influence of the existence of the
gate valve 102 on film forming conditions are particularly large at
an edge portion of the substrate near the gate valve 102 and is
small at a central portion of the substrate. In the fourth
embodiment of the present invention, therefore, independent
temperature control of the third portion 16j opposed to the gate
valve 102 at an outer edge portion of the plate part is enabled.
The temperature of the third portion 16j is set in consideration of
the specialty of film forming conditions at the third portion 16j,
thus enabling control of the film thickness and film quality of a
film formed on the substrate on the third portion 16j.
[0074] Since the first heater 50, the second heater 52 and the
plurality of third heaters 124, 126, 128, and 130 are provided
concentrically with each other, temperature settings can be made in
consideration of changes in film forming conditions dependent on
the distance from the center of the plate part (center-edge
relationship) in the same way as in the susceptor in the second
embodiment. That is, with the susceptor and the substrate
processing apparatus according to the fourth embodiment of the
present invention, a film thickness distribution and a film quality
distribution selected as desired can be realized while correcting
the center-edge relationship, the influence of the existence of the
gas exhaust part 40 and the influence of the existence of the gate
valve 102.
[0075] The number of third portions is not limited to four. A
plurality of third portions may be used. If the number of portions
which can be independently temperature-controlled is increased, for
example, by increasing the number of grooved portions and freely
changing the shapes of grooved portions, a complicated film
thickness distribution or film quality distribution can be
realized.
Fifth Embodiment
[0076] FIG. 9 is a sectional view of a susceptor and other members
according to the fifth embodiment. This susceptor is similar to the
susceptor according to the second embodiment
[0077] (FIG. 6). However, the widths of the grooves 16A' and 16B'
formed in the heat insulating portion 16A and the outer heat
insulating portion 16B are larger than those in the second
embodiment. Also, a first closing part 160 is provided on the first
portion 16a. The first closing part 160 closes part of the groove
16A' in the grooved portion without contacting the second portion
16b. The shape (planar shape) of the first closing part 160 as
viewed in plan is circular. A second closing part 162 is provided
on the second portion I 6b. The second closing part 162 closes part
of the groove 16A' in the grooved portion and part of the groove
16B' without contacting the first portion 16a and the first closing
part 160. The planer shape of the second closing part 162 is
annular, surrounding the first closing part 160.
[0078] A third closing part 164 is provided on the third portion
16c. The third closing part 164 closes part of the groove 16B'
without contacting the second portion 16b and the second closing
part 162. The planer shape of the third closing part 164 is
annular, surrounding the second closing part 162. The substrate 70
to be processed is placed on the first closing part 160, the second
closing part 162 and the third closing part 164. The material of
the first to third closing parts 160, 162, and 164 is not
particularly specified, if it does not largely impede plasma
discharge. The material may be, for example, a ceramic or Al.
[0079] The effect of thermally insulating the first portion 16a and
the second portion 16b from each other and the effect of thermally
insulating the second portion 16b and the third portion 16e from
each other can be improved by increasing the width (x3) of the
groove 16A' and the width (x4) of the groove 16B'. However, if the
substrate is heated while being directly placed on the plate part
having the width (x3) of the groove 16A' and the width (x4) of the
groove 16B' increased, then the substrate temperature is not
sufficiently increased at the positions right above the grooves
16A' and 16B'. That is, unintended temperature variation
occurs.
[0080] To prevent this, the first to third closing parts 160, 162,
and 164 are provided. The first closing part 160 and the second
closing part 162 close part of the groove 16A'. Therefore the
distance (xl) between the first closing part 160 and the second
closing part 162 is smaller than the width (x3) of the groove 16A'.
The second closing part 162 and the third closing part 164 close
part of the groove 16B'. Therefore the distance (x2) between the
second closing part 162 and the third closing part 164 is smaller
than the width (x4) of the groove 16B'. Consequently, unintended
temperature variation can be limited in comparison with the case
where the substrate is directly placed on the plate part 16.
[0081] It is preferable to change the number of closing parts
according to the number of grooves formed in the plate part. For
example, in a case where only the groove 16A' is formed in the
plate part, the third closing part 164 is not provided. Sixth
Embodiment
[0082] FIG. 10 is a sectional view of a susceptor according to the
sixth embodiment. The first portion 16a, the second portion 16b and
the third portion 16c are separate parts. In other words, the third
portion 16c can be detached from the second portion 16b. The second
portion 16b can be detached from the first portion 16a. The second
portion 16b and the third portion 16c are annular parts as viewed
in plan. A projection 160 is provided on a side surface of the
first portion 16a, and the second portion 16b is put on this
projection 160. A projection 162 is provided on a side surface of
the second portion 16b, and the third portion 16c is put on this
projection 162.
[0083] The grooved portion (heat insulating portion 16A) is formed
by the side surface of the first portion 16a, an upper surface of
the projection 160, and a side surface of the second portion 16b.
The outer heat insulating portion 16B is formed by the side surface
of the second portion 16b, an upper surface of the projection 162
and a side surface of the third portion 16c.
[0084] As is apparent from FIG. 10, the deep groove 16A' can be
provided by providing the projection 160 at the lower end of the
side surface of the first portion 16a and by reducing the thickness
of the projection 160. The deep groove 16B' can be provided by
providing the projection 162 at the lower end of the side surface
of the second portion 16b and by reducing the thickness of the
projection 162. If the groove is made deep in the susceptor in the
first embodiment, there is an apprehension that the strength of the
susceptor is considerably reduced. However, the susceptor according
to the sixth embodiment of the present invention is capable of
securing the strength while making the groove deep, since it is of
an assembly type.
Seventh Embodiment
[0085] FIG. 11 is a sectional view of a susceptor and other members
according to the seventh embodiment. This susceptor has a cooling
member 200 attached to the plate part 16, and a cooling member 202
attached to the slide shaft 18. The cooling members 200 and 202 are
not particularly specified, if a well-known cooling method is used.
The cooling member 200 is attached right below the grooved portions
of the plate part 16 (heat insulating portion 16A and outer heat
insulating portion 16B). The degrees of cooling by the cooling
members 200 and 202 are controlled by the heater controller.
[0086] For example, when plasma is caused to arise at 1 kW, the
temperature of the susceptor is increased to a certain degree by RF
energy. In some cases, this temperature rise makes it difficult to
realize a low-temperature process. In the susceptor according to
the seventh embodiment of the present invention, therefore, the
susceptor is cooled with the cooling members 200 and 202 to limit
the rise in temperature of the susceptor, thereby enabling a
low-temperature process to be realized.
[0087] On the upper surface side of the plate part, the first
portion 16a, the second portion 16b and the third portion 16c are
thermally separated from each other. On the lower surface side of
the plate part, however, these portions are not thermally separated
from each other. Therefore, heat transfer between the first to
third portions 16a, 16b, and 16c occurs mainly on the lower surface
side of the plate part. In the susceptor according to the seventh
embodiment of the present invention, the cooling member 200 is
provided on the lower surface side of the plate part 16 to limit
this heat transfer. More specifically, the cooling member 200 is
provided right below the grooved portions (heat insulating portion
16A and outer heat insulating portion 16B), thereby enabling
limiting of heat transfer between the first portion 16a and the
second portion 16b and heat transfer between the second portion 16b
and the third portion 16c. The cooling member 200 may be embedded
in the plate part 16, and the cooling member 202 may be embedded in
the slide shaft 18.
Eighth Embodiment
[0088] FIG. 12 is a sectional view of a susceptor according to the
eighth embodiment. In the first to seventh embodiments, the grooved
portion is provided in the plate part on the upper surface side as
a heat insulating portion for thermally insulating the first
portion and the second portion of the plate part from each other.
However, a heat insulating portion in the eighth embodiment is a
cooling device 210 provided in the plate part 16. The degree of
cooling with the cooling device 210 is controlled by the heater
controller. A first heater 50 and a second heater 52 are operated
while the cooling device 210 is operated. Then the first portion
16a and the second portion 16b are thermally insulated from each
other by cooling with the cooling device 210. It is preferable to
thermally insulate the first portion 16a and the second portion 16b
particularly on the upper surface side of the plate part 16.
Thermal insulation of the first portion 16a and the second portion
16b enables creating a definite temperature difference in the
substrate without providing any groove. A suitable combination of
the embodiments described above may be made and used.
[0089] According to the present invention, certain different
regions in the susceptor are thermally insulated from each other by
a heat insulating portion, thus enabling creating a definite
temperature difference.
[0090] Obviously many modifications and variations of the present
invention are possible in the light of the above teachings. It is
therefore to be understood that within the scope of the appended
claims the invention may be practiced otherwise than as
specifically described.
* * * * *