U.S. patent application number 15/630549 was filed with the patent office on 2017-12-28 for substrate processing system and temperature control method.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. The applicant listed for this patent is TOKYO ELECTRON LIMITED. Invention is credited to Kenichiro NAKAMURA, Satoru TERUUCHI, Kenichiro YAMADA, Takari YAMAMOTO.
Application Number | 20170372928 15/630549 |
Document ID | / |
Family ID | 60677772 |
Filed Date | 2017-12-28 |
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United States Patent
Application |
20170372928 |
Kind Code |
A1 |
YAMADA; Kenichiro ; et
al. |
December 28, 2017 |
SUBSTRATE PROCESSING SYSTEM AND TEMPERATURE CONTROL METHOD
Abstract
Disclosed is a substrate processing system including a substrate
processing apparatus; and a control device that controls the
substrate processing apparatus. The substrate processing apparatus
includes: a chamber; a placing table provided within the chamber;
and heaters embedded in the placing table corresponding to division
regions, respectively. The control device includes: a holding unit
that holds a table for each of the division regions; a measuring
unit that measures the resistance value of each of the heaters
embedded in the placing table for each of the division regions; and
a controller that estimates a temperature of each of the division
regions corresponding to the resistance value of each of the
heaters measured by the measuring unit with reference to the table
for each of the division regions, and controls an electric power to
be supplied to each of the heaters so that the estimated
temperature becomes a target temperature.
Inventors: |
YAMADA; Kenichiro; (Miyagi,
JP) ; TERUUCHI; Satoru; (Miyagi, JP) ;
NAKAMURA; Kenichiro; (Miyagi, JP) ; YAMAMOTO;
Takari; (Miyagi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOKYO ELECTRON LIMITED |
Tokyo |
|
JP |
|
|
Assignee: |
TOKYO ELECTRON LIMITED
Tokyo
JP
|
Family ID: |
60677772 |
Appl. No.: |
15/630549 |
Filed: |
June 22, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 2237/334 20130101;
H01L 21/67248 20130101; H01L 21/6831 20130101; C23C 16/52 20130101;
C23C 16/46 20130101; C23C 16/50 20130101; C23C 16/5096 20130101;
H01J 37/32724 20130101; H01L 21/67109 20130101; H01L 21/67103
20130101; C23C 16/463 20130101; H05B 1/0233 20130101; H01J 37/32009
20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; C23C 16/52 20060101 C23C016/52; C23C 16/50 20060101
C23C016/50; H01J 37/32 20060101 H01J037/32; H05B 1/02 20060101
H05B001/02; H01L 21/683 20060101 H01L021/683 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2016 |
JP |
2016-125791 |
Claims
1. A substrate processing system comprising: a substrate processing
apparatus; and a control device that controls the substrate
processing apparatus, the substrate processing apparatus
comprising: a chamber; a placing table provided within the chamber,
on which a processing target substrate is placed; and heaters
embedded in the placing table corresponding to division regions,
respectively, that is, a plurality of divided regions of the top
surface of the placing table, the control device comprising: a
holding unit that holds a table for each of the division regions,
the table indicating a relationship between a resistance value of
each of the heaters embedded in the placing table and a temperature
of each of the division regions; a measuring unit that measures the
resistance value of each of the heaters embedded in the placing
table for each of the division regions; and a controller that
estimates a temperature of each of the division regions
corresponding to the resistance value of each of the heaters
measured by the measuring unit with reference to the table for each
of the division regions, and controls an electric power to be
supplied to each of the heaters so that the estimated temperature
becomes a target temperature.
2. The substrate processing system of claim 1, wherein an AC
voltage and an AC current are supplied to each of the heaters, and
the measuring unit measures the resistance value of each of the
heaters based on instantaneous values of the AC voltage and the AC
current at an intermediate timing between adjacent zero-cross
points at which the instantaneous value of the AC voltage supplied
to each of the heaters becomes 0 V.
3. The substrate processing system of claim 1, wherein a
temperature sensor is provided in the placing table corresponding
to at least one of the division regions, and when a difference
equal to or larger than a predetermined value occurs between a
temperature of the division region measured by the temperature
sensor and a temperature estimated based on a resistance value of
the heater provided in the division region, the controller corrects
temperatures estimated for all division regions based on the
difference.
4. A temperature control method that controls the temperature of a
surface of a placing table on a substrate processing apparatus
including: a chamber, a placing table provided within the chamber,
on which a processing target substrate is placed, and heaters
embedded in the placing table corresponding to division regions,
respectively, that is, a plurality of divided regions of the top
surface of the placing table, the method being performed by a
control device and, comprising: measuring the resistance value of
each of the heaters embedded in the placing table for each of the
division regions; estimating a temperature of each of the division
regions corresponding to the resistance value of each of the
heaters measured with reference to the table for each of the
division regions, the table indicating a relationship between a
resistance value of each of the heaters embedded in the placing
table and a temperature of each of the division regions; and
controlling an electric power to be supplied to each of the heaters
so that the estimated temperature becomes a target temperature.
5. The temperature control method of claim 4, wherein an AC voltage
and an AC current are supplied to each of the heaters, and in the
measuring of the resistance value, the resistance value of each of
the heaters is measured based on instantaneous values of the AC
voltage and the AC current at an intermediate timing between
adjacent zero-cross points at which the instantaneous value of the
AC voltage supplied to each of the heaters becomes 0 V.
6. The temperature control method of claim 4, wherein a temperature
sensor is provided in the placing table corresponding to at least
one of the division regions, and in the controlling of the electric
power, when a difference equal to or larger than a predetermined
value occurs between a temperature of the division region measured
by the temperature sensor and a temperature estimated based on a
resistance value of the heater provided in the division region,
temperatures estimated for all division regions are corrected based
on the difference.
7. The temperature control method of claim 6 further comprising:
executing creating the table, wherein the creating of the table
further including: controlling an electric power to be supplied to
the heater provided in the division region for each setting
temperature based on a temperature measured by the temperature
sensor so that the temperature of the division region provided with
the temperature sensor becomes the setting temperature; measuring a
radiation amount of light with a predetermined wavelength emitted
from each of the division regions, for each setting temperature,
using a camera; controlling an electric power to be supplied to
each of the heaters provided in each of the division regions so
that a difference between the radiation amount of light with a
predetermined wavelength emitted from other division regions not
provided with the temperature sensor, and the radiation amount of
light with a predetermined wavelength emitted from the division
region provided with the temperature sensor falls within a
predetermined value, for each setting temperature; measuring a
resistance value of each of the heaters provided in each of the
division regions, for each setting temperature; and creating a
table in which the setting temperature is associated with the
resistance value of each of the heaters provided in each of the
division regions.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority from
Japanese Patent Application No. 2016-125791 filed on Jun. 24, 2016
with the Japan Patent Office, the disclosure of which is
incorporated herein in its entirety by reference.
TECHNICAL FIELD
[0002] Various aspects and exemplary embodiments of the present
disclosure relate to a substrate processing system and a
temperature control method.
BACKGROUND
[0003] In a semiconductor manufacturing process, the temperature of
a semiconductor wafer as a processing target substrate is one of
important factors that determine the characteristics of a
semiconductor. Thus, in the manufacturing process, it is required
to control the temperature of the semiconductor wafer with high
accuracy. In order to implement this, for example, it may be
considered that a placing table on which the semiconductor wafer is
to be placed is divided into a plurality of regions, and
independently controllable heaters are provided in the respective
divided regions.
[0004] However, even when the independently controllable heaters
are provided in the respective divided regions on the placing
table, it is difficult to determine whether the temperature of each
of the regions is controlled to a desired temperature. Thus, it may
be considered that a temperature sensor is provided in each region
in addition to the heater. Accordingly, it becomes possible to
control the temperature of each region on the placing table with
high accuracy. See, e.g., Japanese Patent Laid-Open Publication No.
2006-283173.
SUMMARY
[0005] In an aspect of the present disclosure, the substrate
processing system includes, a substrate processing apparatus and a
control device that controls the substrate processing apparatus.
The substrate processing apparatus includes a chamber, a placing
table provided within the chamber, on which a processing target
substrate is placed, and heaters embedded in the placing table
corresponding to division regions, respectively, that is, a
plurality of divided regions of the top surface of the placing
table. The control device includes: a holding unit that holds a
table for each of the division regions, the table indicating a
relationship between a resistance value of each of the heaters
embedded in the placing table and a temperature of each of the
division regions; a measuring unit that measures the resistance
value of each of the heaters embedded in the placing table for each
of the division regions; and a controller that estimates a
temperature of each of the division regions corresponding to the
resistance value of each of the heaters measured by the measuring
unit with reference to the table for each of the division regions,
and controls an electric power to be supplied to each of the
heaters so that the estimated temperature becomes a target
temperature.
[0006] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a system configuration view illustrating an
example of a substrate processing system.
[0008] FIG. 2 is a sectional view illustrating an example of a
configuration of a substrate processing apparatus according to a
first exemplary embodiment.
[0009] FIG. 3 is a view illustrating an example of a top surface of
an electrostatic chuck.
[0010] FIG. 4 is a block diagram illustrating an example of a
configuration of a control device.
[0011] FIG. 5 is a view illustrating exemplary waveforms of an AC
voltage and an AC current supplied to each heater.
[0012] FIG. 6 is a view illustrating an exemplary timing when a
resistance value of each heater is measured.
[0013] FIG. 7 is a view illustrating an example of a conversion
table.
[0014] FIG. 8 is a flow chart illustrating an example of an
operation of the control device in the first exemplary
embodiment.
[0015] FIG. 9 is a sectional view illustrating an example of a
configuration of a substrate processing apparatus according to a
second exemplary embodiment.
[0016] FIG. 10 is a flow chart illustrating an example of an
operation of a control device in the second exemplary
embodiment.
[0017] FIGS. 11A to 11D are views for explaining an effect of
correction by a temperature sensor.
[0018] FIG. 12 is a sectional view illustrating an example of a
configuration of a substrate processing apparatus when a conversion
table is created.
[0019] FIG. 13 is a flow chart illustrating an example of an
operation of a control device in a third exemplary embodiment.
[0020] FIG. 14 is a view illustrating an example of a computer that
implements functions of the control device.
DETAILED DESCRIPTION
[0021] In the following detailed description, reference is made to
the accompanying drawing, which form a part hereof. The
illustrative embodiments described in the detailed description,
drawing, and claims are not meant to be limiting. Other embodiments
may be utilized, and other changes may be made without departing
from the spirit or scope of the subject matter presented here.
[0022] The demand for accuracy in the temperature control of the
semiconductor wafer is increasing day by day according to the
miniaturization of a process. Thus, it becomes necessary to control
the temperature of the semiconductor wafer in each smaller region,
and thus the number of divided regions on the placing table is
increased. When the number of divided regions on the placing table
is increased, the number of heaters and the number of temperature
sensors provided in the placing table are increased. This makes it
difficult to miniaturize the placing table. When the number of
heaters and the number of temperature sensors provided in the
placing table are increased, the structure of the placing table
becomes complicated, and the degree of freedom in design is
decreased.
[0023] The disclosed substrate processing system, according to an
aspect, includes, a substrate processing apparatus and a control
device that controls the substrate processing apparatus. The
substrate processing apparatus includes a chamber, a placing table
provided within the chamber, on which a processing target substrate
is placed, and heaters embedded in the placing table corresponding
to division regions, respectively, that is, a plurality of divided
regions of the top surface of the placing table. The control device
includes: a holding unit that holds a table for each of the
division regions, the table indicating a relationship between a
resistance value of each of the heaters embedded in the placing
table and a temperature of each of the division regions; a
measuring unit that measures the resistance value of each of the
heaters embedded in the placing table for each of the division
regions; and a controller that estimates a temperature of each of
the division regions corresponding to the resistance value of each
of the heaters measured by the measuring unit with reference to the
table for each of the division regions, and controls an electric
power to be supplied to each of the heaters so that the estimated
temperature becomes a target temperature.
[0024] In the disclosed substrate processing system, according to
an aspect, an AC voltage and an AC current are supplied to each of
the heaters, and the measuring unit may measure the resistance
value of each of the heaters based on instantaneous values of the
AC voltage and the AC current at an intermediate timing between
adjacent zero-cross points at which the instantaneous value of the
AC voltage supplied to each of the heaters becomes 0 V.
[0025] In the disclosed substrate processing system, according to
an aspect, a temperature sensor may be provided in the placing
table corresponding to at least one of the division regions. When a
difference equal to or larger than a predetermined value occurs
between a temperature of the division region measured by the
temperature sensor and a temperature estimated based on a
resistance value of the heater provided in the division region, the
controller may correct temperatures estimated for all division
regions based on the difference.
[0026] The disclosed temperature control method, according to an
aspect, controls the temperature of a surface of a placing table on
a substrate processing apparatus. The substrate processing
apparatus includes: a chamber, a placing table provided within the
chamber, on which a'processing target substrate is placed, and
heaters embedded in the placing table corresponding to division
regions, respectively, that is, a plurality of divided regions of
the top surface of the placing table. In the temperature control
method, the control device executes: measuring the resistance value
of each of the heaters embedded in the placing table for each of
the division regions; estimating a temperature of each of the
division regions corresponding to the resistance value of each of
the heaters measured with reference to the table for each of the
division regions, the table indicating a relationship between a
resistance value of each of the heaters embedded in the placing
table and a temperature of each of the division regions; and
controlling an electric power to be supplied to each of the heaters
so that the estimated temperature becomes a target temperature.
[0027] In the disclosed temperature control method, according to an
aspect, an AC voltage and an AC current are supplied to each of the
heaters. In the measuring of the resistance value, the resistance
value of each of the heaters may be measured based on instantaneous
values of the AC voltage and the AC current at an intermediate
timing between adjacent zero-cross points at which the
instantaneous value of the AC voltage supplied to each of the
heaters becomes 0 V.
[0028] In the disclosed temperature control method, according to an
aspect, a temperature sensor may be provided in the placing table
corresponding to at least one of the division regions. In the
controlling of the electric power, when a difference equal to or
larger than a predetermined value occurs between a temperature of
the division region measured by the temperature sensor and a
temperature estimated based on a resistance value of the heater
provided in the division region, temperatures estimated for all
division regions may be corrected based on the difference.
[0029] In the disclosed temperature control method, according to an
aspect, the control device may further execute creating the table.
The creating of the table may include: controlling an electric
power to be supplied to the heater provided in the division region
for each setting temperature based on a temperature measured by the
temperature sensor so that the temperature of the division region
provided with the temperature sensor becomes the setting
temperature; measuring a radiation amount of light with a
predetermined wavelength emitted from each of the division regions,
for each setting temperature, using a camera; controlling an
electric power to be supplied to each of the heaters provided in
each of the division regions so that a difference between the
radiation amount of light with a predetermined wavelength emitted
from other division regions not provided with the temperature
sensor, and the radiation amount of light with a predetermined
wavelength emitted from the division region provided with the
temperature sensor falls within a predetermined value, for each
setting temperature; measuring a resistance value of each of the
heaters provided in each of the division regions, for each setting
temperature; and creating a table in which the setting temperature
is associated with the resistance value of each of the heaters
provided in each of the division regions.
[0030] According to various aspects and exemplary embodiments of
the present disclosure, the placing table may be miniaturized and
the structure thereof may be simplified.
[0031] Hereinafter, exemplary embodiments of the disclosed
substrate processing system and temperature control method will be
described in detail with reference to drawings. The present
disclosure is not limited by the following exemplary embodiments.
Respective exemplary embodiments may be properly combined within a
range that does not make the processing contents thereof
inconsistent with each other.
First Exemplary Embodiment
[0032] [System Configuration of Substrate Processing System 10]
[0033] FIG. 1 is a system configuration view illustrating an
example of a substrate processing system 10. As illustrated in FIG.
1, for example, the substrate processing system 10 includes a
substrate processing apparatus 100 and a control device 200. The
substrate processing apparatus 100 performs a processing such as,
for example, plasma etching, plasma chemical vapor deposition
(CVD), or heat treatment on a semiconductor wafer W as an example
of a target substrate. The control device 200 controls each unit of
the substrate processing apparatus 100, and causes the substrate
processing apparatus 100 to execute a predetermined processing on
the semiconductor wafer W carried into the substrate processing
apparatus 100.
[0034] [Configuration of Substrate Processing Apparatus 100]
[0035] FIG. 2 is a sectional view illustrating an example of a
configuration of the substrate processing apparatus 100 according
to the first exemplary embodiment. In the present exemplary
embodiment, as illustrated in FIG. 2, the substrate processing
apparatus 100 includes, for example, a chamber 1 that is
hermetically configured and electrically grounded. The chamber 1 is
formed in a substantially cylindrical shape by, for example,
aluminium having a surface covered with an anodic oxide film.
[0036] A base unit 2a made of a conductive metal such as, for
example, aluminum, is provided within the chamber 1. The base unit
2a serves as a lower electrode. The base unit 2a is supported by a
conductor support base 4 provided on an insulating plate 3. A focus
ring 5 made of, for example, a single crystal silicon is provided
at the upper outer periphery of the base unit 2a. Around the base
unit 2a and the support base 4, a cylindrical inner wall member 3a
made of, for example, quartz, is further provided to surround the
base unit 2a and the support base 4.
[0037] A shower head 16 serving as an upper electrode is provided
above the base unit 2a to face the base unit 2a substantially in
parallel, that is, to face the semiconductor wafer W placed on the
base unit 2a. The shower head 16 and the base unit 2a serve as a
pair of electrodes (an upper electrode and a lower electrode). A
high-frequency power supply 12a is connected to the base unit 2a
through a matcher 11a. A high-frequency power supply 12b is
connected to the base unit 2a through a matcher 11b.
[0038] The high-frequency power supply 12a supplies a high
frequency power at a predetermined frequency (e.g., 100 MHz) used
for plasma generation to the base unit 2a. The high-frequency power
supply 12b supplies a high frequency power at a predetermined
frequency used for ion attraction (bias), that is, a frequency
(e.g., 13 MHz) lower than that of the high-frequency power supply
12a, to the base unit 2a. For example, the power ON/OFF of the
high-frequency power supplies 12a and 12b, and the high-frequency
power supplied by the high-frequency power supplies 12a and 12b are
controlled by the control device 200 to be described below.
[0039] An electrostatic chuck 6 is provided on the top surface of
the base unit 2a to attract and hold the semiconductor wafer W, and
to heat the semiconductor wafer W. The electrostatic chuck 6
includes insulators 6b, an electrode 6a provided between the
insulators 6b, and a plurality of heaters 6c. The electrode 6a is
connected to a DC power supply 13. The heaters 6c are connected to
the control device 200 to be described below. The electrostatic
chuck 6 generates a Coulomb force on the surface of the
electrostatic chuck 6 by a DC voltage applied from the DC power
supply 13, and attracts and holds the semiconductor wafer W on the
top surface of the electrostatic chuck 6 by the Coulomb force. The
power ON/OFF of the DC power supply 13 is controlled by the control
device 200 to be described below.
[0040] The electrostatic chuck 6 heats the semiconductor wafer W by
the heaters 6c heated by the electric power supplied from the
control device 200. The top surface of the electrostatic chuck 6 is
divided into a plurality of division regions, and one heater 6c is
provided in each of the division regions. The base unit 2a and the
electrostatic chuck 6 are examples of a placing table.
[0041] A flow path 2b is formed within the base unit 2a, through
which a refrigerant such as, for example, galden, flows, and a
chiller unit 33 is connected to the flow path 2b through pipes 2c
and 2d. While the refrigerant supplied from the chiller unit 33
circulates through the inside of the flow path 2b, the base unit 2a
is cooled through heat exchange with the refrigerant. For example,
the temperature and the flow rate of the refrigerant supplied by
the chiller unit 33 are controlled by the control device 200 to be
described below.
[0042] In the base unit 2a, a pipe 32 is provided through the base
unit 2a so as to supply a heat transfer gas (a backside gas) such
as, for example, a helium gas, to the rear surface side of the
semiconductor wafer W. The pipe 32 is connected to a heat transfer
gas supply unit 31. For example, the flow rate of the heat transfer
gas supplied to the rear surface side of the semiconductor wafer W
from the heat transfer gas supply unit 31 through the pipe 32 is
controlled by the control device 200 to be described below.
[0043] The control device 200 controls the temperature of the
refrigerant flowing through the flow path 2b, the electric power
supplied to each of the heaters 6c within the electrostatic chuck
6, and the flow rate of the heat transfer gas supplied to the rear
surface of the semiconductor wafer W, thereby controlling the
temperature of the semiconductor wafer W attracted and held on the
top surface of the electrostatic chuck 6 to a temperature within a
predetermined range.
[0044] The shower head 16 is provided at the top portion of the
chamber 1. The shower head 16 includes a body portion 16a, and an
upper top plate 16b constituting an electrode plate, and supported
at the top portion of the chamber 1 through an insulating member
45. The body portion 16a is made of, for example, aluminum with a
surface that has been subjected to anodic oxidation treatment, and
detachably supports the upper top plate 16b at the bottom portion
thereof. The upper top plate 16b is made of, for example, a
silicon-containing material, e.g., quartz.
[0045] A gas diffusion chamber 16c is provided within the body
portion 16a. A plurality of gas outlets 16e are formed at the
bottom portion of the body portion 16a so as to be located under
the gas diffusion chamber 16c. A plurality of gas introducing holes
16f are provided in the upper top plate 16b to extend through the
upper top plate 16b in the thickness direction, and the gas
introducing holes 16f communicate with the above described gas
outlets 16e, respectively. Through this configuration, a processing
gas supplied to the gas diffusion chamber 16c is supplied into the
chamber 1 through each of the gas outlets 16e and the gas
introducing holes 16f to be diffused in a shower form. A
temperature regulator such as, for example, a pipe (not
illustrated) configured to circulate a refrigerant or a heater (not
illustrated) is provided in, for example, the body portion 16a, and
is configured to control the shower head 16 to a temperature within
a desired range during the processing of the semiconductor wafer
W.
[0046] A gas introducing port 16g is formed in the body portion 16a
to introduce the processing gas to the gas diffusion chamber 16c.
The gas introducing port 16g is connected to one end of a pipe 15b,
and a processing gas supply source 15 that supplies the processing
gas used for the processing of the semiconductor wafer W is
connected to the other end of the pipe 15b via a valve V and a mass
flow controller (MFC) 15a. The processing gas supplied from the
processing gas supply source 15 is supplied to the gas diffusion
chamber 16c through the pipe 15b, and supplied into the chamber 1
through each of the gas outlets 16e and the gas introducing holes
16f to be diffused in a shower form. The valve V and the MFC 15a
are controlled by the control device 200 to be described below.
[0047] A variable DC power supply 42 is electrically connected to
the shower head 16 through a low pass filter (LPF) 40 and a switch
41. The variable DC power supply 42 is capable of supplying or
cutting off a DC voltage by the switch 41. The current and the
voltage of the variable DC power supply 42 and the turning on/off
of the switch 41 are controlled by the control device 200 to be
described below. For example, when a high frequency power is
supplied from the high-frequency power supplies 12a and 12b to the
base unit 2a and plasma is generated in a processing space within
the chamber 1, the switch 41 is turned ON by the control device 200
as necessary, and a DC voltage at a predetermined magnitude is
applied to the shower head 16 serving as an upper electrode.
[0048] An exhaust port 71 is formed at the bottom portion of the
chamber 1. An exhaust device 73 is connected to the exhaust port 71
through an exhaust pipe 72. The exhaust device 73 includes a vacuum
pump, and is configured to decompress the inside of the chamber 1
to a predetermined vacuum degree by operating the vacuum pump. For
example, the exhaust flow rate of the exhaust device 73 is
controlled by the control device 200 to be described below. An
opening 74 is formed in the side wall of the chamber 1, and a gate
valve G for opening and closing the opening 74 is provided in the
opening 74.
[0049] A deposition shield 76 is detachably provided along an inner
wall surface, on the inner wall of the chamber 1. A deposition
shield 77 is provided on an outer peripheral surface of the inner
wall member 3a to cover the inner wall member 3a. The deposition
shields 76 and 77 prevent etching by-product (deposition) from
being attached to the inner wall of the chamber 1. A conductive
member (GND block) 79 connected to a ground in a DC manner is
provided at a position of the deposition shield 76 having
substantially the same height as the semiconductor wafer W
attracted and held on the electrostatic chuck 6. An abnormal
discharge in the chamber 1 is suppressed by the conductive member
79.
[0050] A ring magnet 9 is concentrically disposed around the
chamber 1. The ring magnet 9 forms a magnetic field in a space
between the shower head 16 and the base unit 2a. The ring magnet 9
is rotatably held by a rotation mechanism (not illustrated).
[0051] [Electrostatic Chuck 6]
[0052] FIG. 3 is a view illustrating an example of the top surface
of the electrostatic chuck 6. The focus ring 5 is provided at the
outer periphery of the electrostatic chuck 6 to surround the
electrostatic chuck 6. The top surface of the electrostatic chuck 6
on which the semiconductor wafer W is placed is divided into a
plurality of division regions 60. Each of the division regions 60
corresponds to each region obtained when the top surface of the
electrostatic chuck 6 is concentrically divided into a plurality of
regions, and each of concentric regions excluding the central
region is further divided into a plurality of regions in the
circumferential direction.
[0053] In the present exemplary embodiment, the top surface of the
electrostatic chuck 6 is concentrically divided into, for example,
five regions as illustrated in FIG. 3. Among the five concentric
regions, the second region from the center is divided into, for
example, three regions in the circumferential direction as
illustrated in FIG. 3. The third region from the center is divided
into, for example, six regions in the circumferential direction as
illustrated in FIG. 3. The fourth region from the center is divided
into, for example, nine regions in the circumferential direction as
illustrated in FIG. 3. The outermost region is divided into, for
example, eight regions in the circumferential direction as
illustrated in FIG. 3. As described above, in the present exemplary
embodiment, the top surface of the electrostatic chuck 6 is divided
into 27 division regions 60. A method of dividing the top surface
of the electrostatic chuck 6 is not limited to the example
illustrated in FIG. 3.
[0054] One heater 6c is provided corresponding to each of the
division regions 60 within the electrostatic chuck 6. An electric
power to be supplied to the heater 6c provided in each of the
division regions 60 is independently controlled by the control
device 200. One heater (not illustrated) is also provided along the
shape of the focus ring 5 within the focus ring 5, and an electric
power to be supplied to the heater is controlled by the control
device 200. The control device 200 independently controls the
electric power to be supplied to each of the 27 heaters 6c provided
in each of the division regions 60 of the electrostatic chuck 6,
and the electric power to be supplied to one heater provided in the
focus ring 5.
[0055] [Configuration of Control Device 200]
[0056] FIG. 4 is a block diagram illustrating an example of the
control device 200. As illustrated in FIG. 4, the control device
200 includes, for example, a plurality of power supply units 20-1
to 20-n, a measuring unit 24, a controller 25, and a holding unit
26. Hereinafter, when the plurality of power supply units 20-1 to
20-n are not distinguished from each other but are generically
named, the power supply units 20-1 to 20-n are simply referred to
as power supply units 20.
[0057] One power supply unit 20 is provided in each of the heaters
6c provided in each of the division regions 60 of the electrostatic
chuck 6, and supplies an electric power to the corresponding heater
6c. In the present exemplary embodiment, 28 heaters 6c are provided
within the substrate processing apparatus 100, and 28 power supply
units 20 are provided corresponding to the heaters 6c,
respectively. Each of the power supply units 20 includes a switch
(SW) 21, an ammeter 22, and a voltmeter 23.
[0058] The SW 21 is switched ON/OFF according to the control from
the controller 25, and supplies an electric power supplied from a
power supply 27 to the corresponding heater 6c during the ON
period. The ammeter 22 measures an instantaneous value of an AC
current supplied to the corresponding heater 6c from the power
supply 27, and outputs the measured instantaneous value to the
measuring unit 24. The voltmeter 23 measures an instantaneous value
of an AC voltage supplied to the corresponding heater 6c from the
power supply 27, and outputs the measured instantaneous value to
the measuring unit 24.
[0059] The measuring unit 24 measures a resistance value of each
heater 6c based on the measured voltage and current values of the
heater 6c which are output from each power supply unit 20. Then,
the measuring unit 24 outputs the measured resistance value of each
heater 6c to the controller 25. For example, as illustrated in FIG.
5, an AC voltage at a predetermined frequency (e.g., 50 Hz) is
output from the power supply 27, and at a timing when the SW 21 is
switched on, a voltage and a current are supplied to the heater 6c.
FIG. 5 is a view illustrating exemplary waveforms of an AC voltage
and an AC current supplied to each heater 6c.
[0060] The measuring unit 24 measures a resistance value of each
heater 6c based on instantaneous values of an AC voltage and an AC
current in the middle between adjacent zero-cross points in each
heater 6c. The zero-cross points are, for example, timings t.sub.1
and t.sub.2 at which the instantaneous value of the AC voltage
becomes 0 V as illustrated in FIG. 6. Specifically, the measuring
unit 24 measures, for example, a ratio of instantaneous values of
the AC voltage and the AC current measured in the period .DELTA.t
that is an intermediate timing between the adjacent zero-cross
points t.sub.1 and t.sub.2, as a resistance value of each heater
6c, as illustrated in FIG. 6.
[0061] Here, since, for example, various manufacturing apparatuses
or conveying apparatuses are operating in a factory where
semiconductors are manufactured, various noises are included in a
power supply used in the factory. Thus, when an electric power is
supplied to the heaters 6c using the power supply within the
factory, variations occur in the measured voltage and current
values due to the influence of noises. Therefore, the measuring
unit 24 according to the present exemplary embodiment measures a
resistance value of each of the heaters 6c from, for example, a
ratio of instantaneous values of the AC voltage and the AC current
measured in an intermediate timing between the adjacent zero-cross
points, as illustrated in FIG. 6. Accordingly, it is possible to
suppress variations in the measured voltage and current values due
to the influence of noises, and to measure the resistance value of
each of the heaters 6c with higher accuracy.
[0062] The measuring unit 24 may further reduce the influence of
noises by measuring a resistance value of each of the heaters 6c a
plurality of times and averaging the measured resistance values.
When a three-phase AC power supply used in the factory is used as
an electric power to be supplied to each of the heaters 6c,
variations of measured resistance values increase due to the
influence of different noises included in each phase. Thus, it is
desirable to supply an AC voltage and an AC current from a
single-phase AC power supply to each of the heaters 6c.
[0063] The holding unit 26 holds, for example, a conversion table
260 as illustrated in FIG. 7. FIG. 7 is a view illustrating an
example of the conversion table 260. As illustrated in FIG. 7, for
example, individual tables 262 are stored in the conversion table
260, for region IDs 261 used for identifying the division regions
60 provided with the heaters 6c, respectively. Resistance values
264 of each of the heaters 6c are stored in association with
temperatures 263 in each of the individual tables 262. The holding
unit 26 holds a recipe indicating a processing of the semiconductor
wafer W. The recipe includes target temperature information of each
of the division regions 60 in each step. For example, the
conversion table 260 and the recipe are created in advance by, for
example, an administrator of the substrate processing system 10 and
stored in the holding unit 26.
[0064] The controller 25 controls each unit of the substrate
processing apparatus 100 based on the recipe held within the
holding unit 26. The controller 25 controls the electric power to
be supplied to each of the heaters 6c provided in each of the
division regions 60 of the electrostatic chuck 6 in each step of
the processing so that the temperature of each of the division
regions 60 is controlled to be a target temperature indicated by
the recipe.
[0065] Specifically, the controller 25 reads the target temperature
information and the conversion table 260 of each division region 60
from the holding unit 26 in each step of the processing. The
controller 25 always acquires a resistance value of each heater 6c
measured by the measuring unit 24. Then, the controller 25, with
reference to the conversion table 260 for each division region 60
of the electrostatic chuck 6, estimates a temperature corresponding
to the resistance value of the heater 6c provided in the division
region 60 as a temperature of the division region 60. Then, the
controller 25 controls the ratio of switching ON/OFF of the SW 21
within the power supply unit 20 according to a difference between
the estimated temperature and a target temperature for each
division region 60, thereby controlling an electric power to be
supplied to the heater 6c.
[0066] Here, when a temperature sensor is provided within the base
unit 2a for each of the division regions 60 of the electrostatic
chuck 6 to measure the temperature of each of the division regions
60, a space in which the temperature sensor is to be arranged is
required in the base unit 2a. The electrostatic chuck 6 may be
divided into more division regions 60 in order to more precisely
control the temperature distribution of the electrostatic chuck 6.
Thus, more temperature sensors may be arranged in the base unit 2a
according to the number of the division regions 60. As the number
of the temperature sensors arranged in the base unit 2a increases,
it becomes difficult to miniaturize the base unit 2a. When the
number of temperature sensors arranged in the base unit 2a are
increased, the structure of the base unit 2a becomes complicated,
and the degree of freedom in design is decreased.
[0067] In contrast, in the substrate processing system 10 according
to the present exemplary embodiment, the temperature of each of the
division regions 60 is estimated based on the resistance value of
each of the heaters 6c provided in each of the division regions 60
within the electrostatic chuck 6. Accordingly, it becomes not
necessary to arrange temperature sensors in the base unit 2a, and
it becomes possible to miniaturize the base unit 2a. Since
temperature sensors arranged in the base unit 2a may be eliminated
or reduced, the structure of the base unit 2a may be simplified,
and the degree of freedom in design is also improved.
[0068] [Operation of Control Device 200]
[0069] FIG. 8 is a flow chart illustrating an example of an
operation of the control device 200 in the first exemplary
embodiment. For example, the control device 200 starts a
temperature control process illustrated in the flow chart when the
process based on the recipe is initiated. Information such as the
conversion table 260 and the recipe is stored in advance in the
holding unit 26.
[0070] First, the controller 25 controls the SW 21 within each
power supply unit 20 to start to supply an electric power to each
heater 6c. Then, the measuring unit 24 measures a resistance value
of the heater 6c in each division region 60 based on an
instantaneous value of an AC current measured by each ammeter 22
and an instantaneous value of an AC voltage measured by each
voltmeter 23 in the middle period between adjacent zero-cross
points of the AC voltage (S100). The measuring unit 24 obtains an
average of resistance values through a plurality of measurements
during a predetermined period (e.g., several seconds) for each
heater 6c, and outputs the average resistance value to the
controller 25.
[0071] Thereafter, the controller 25, with reference to the
conversion table 260 in the holding unit 26 for each division
region 60, estimates a temperature corresponding to the resistance
value of the heater 6c provided in the division region 60, as a
temperature of the division region 60 (S101). Then, the controller
25 controls the ratio of switching ON/OFF of the SW 21 within the
power supply unit 20 according to a difference between the
estimated temperature and a target temperature for each division
region 60, thereby controlling an electric power to be supplied to
the heater 6c (S102).
[0072] Subsequently, the controller 25 determines whether the
processings are completed with reference to the recipe (S103). When
it is determined that the processings are not completed (S103: No),
the measuring unit 24 executes the processing described in step
S100 again. Meanwhile, when it is determined that the processings
are completed (S103: Yes), the control device 200 ends the
temperature control process illustrated in the flow chart.
[0073] As described above, the substrate processing system 10
according to the present exemplary embodiment includes the
substrate processing apparatus 100 and the control device 200. The
substrate processing apparatus 100 includes the chamber 1, the
electrostatic chuck 6 provided within the chamber 1, on which the
semiconductor wafer W is placed, and the heaters 6c embedded in the
electrostatic chuck 6 corresponding to division regions 60,
respectively, that is, a plurality of divided regions of the top
surface of the electrostatic chuck 6. The control device 200
includes: the holding unit 26 that holds the conversion table 260
for each of the division regions 60, the conversion table 260
indicating a relationship between a resistance value of each of the
heaters 6c embedded in the electrostatic chuck 6 and a temperature
of each of the division regions 60; the measuring unit 24 that
measures the resistance value of each heater 6c embedded in the
electrostatic chuck 6 for each division region 60; and the
controller 25 that estimates a temperature of the division region
60 corresponding to the resistance value of the heater 6c measured
by the measuring unit 24 with reference to the conversion table 260
for each division region 60, and controls an electric power to be
supplied to the heater 6c so that the estimated temperature becomes
a target temperature. Accordingly, it becomes possible to
miniaturize the electrostatic chuck 6 and the base unit 2a and to
simplify the structure thereof.
[0074] In the present exemplary embodiment, an AC voltage and an AC
current are supplied to each heater 6c, and the measuring unit 24
measures the resistance value of each heater 6c based on
instantaneous values of the AC voltage and the AC current at an
intermediate timing between adjacent zero-cross points at which the
instantaneous value of the AC voltage supplied to each heater 6c
becomes 0 V. Accordingly, even when a power supply in a factory
with many noises is used, the measuring unit 24 may suppress the
measurement accuracy of the resistance value of each heater 6c from
being lowered.
Second Exemplary Embodiment
[0075] In the above described first exemplary embodiment, since the
temperature of each of the division regions 60 is estimated based
on the resistance value of each of the heaters 6c provided in each
of the division regions 60 within the electrostatic chuck 6, a
temperature sensor for measuring the temperature of the division
regions 60 is not provided. Meanwhile, in the present exemplary
embodiment, a temperature sensor is provided in one among the
plurality of division regions 60. Temperatures estimated for the
division regions 60 are corrected based on a difference between a
temperature estimated from the resistance value of the heater 6c in
the division region 60 provided with the temperature sensor, and a
temperature measured by the temperature sensor.
[0076] [Configuration of Substrate Processing Apparatus 100]
[0077] FIG. 9 is a sectional view illustrating an example of a
configuration of the substrate processing apparatus 100 according
to the second exemplary embodiment. In FIG. 9, members denoted by
the same reference numerals as those in FIG. 2 have the same or
similar functions as the members illustrated in FIG. 2 except for
the points described below, and thus descriptions thereof will be
omitted.
[0078] In the present exemplary embodiment, one temperature sensor
7 is provided in one division region 60 among the plurality of
division regions 60 within the electrostatic chuck 6, within the
base unit 2a below the division region 60, to measure the
temperature of the division region 60. The temperature sensor 7 is,
for example, a fluorescent optical fiber thermometer. The
temperature sensor 7 measures the temperature of one division
region 60 from the rear surface of the electrostatic chuck 6, and
outputs the measured temperature to the control device 200. In the
present exemplary embodiment, the temperature sensor 7 measures the
temperature of one division region 60 among six division regions 60
included in the third concentric region from the center.
[0079] [Operation of Control Device 200]
[0080] FIG. 10 is a flow chart illustrating an example of an
operation of the control device 200 in the second exemplary
embodiment. In FIG. 10, processings denoted by the same reference
numerals as those in FIG. 8 are the same processings as those
illustrated in FIG. 8 except for the points described below, and
thus descriptions thereof will be omitted.
[0081] The controller 25 estimates the temperature of each of the
division regions 60 of the electrostatic chuck 6 (S101), and
acquires information on a temperature T.sub.s of a division region
60 measured by the temperature sensor 7, from the temperature
sensor 7 (S110). In step S110, the controller 25 uses an average of
temperatures of the division region 60 obtained through a plurality
of measurements by the temperature sensor 7 during a predetermined
period (e.g., several seconds), as the temperature T.sub.s of the
division region 60 measured by the temperature sensor 7. Then, the
controller 25 calculates a difference .DELTA.T of the temperature
T.sub.s of the division region 60 measured by the temperature
sensor 7 and a temperature T.sub.e estimated for the division
region 60 provided with the temperature sensor 7 by the following
calculation equation (1) (S111).
.DELTA.T=T.sub.e-T.sub.s (1)
[0082] For example, when the temperature T.sub.e estimated for the
division region 60 provided with the temperature sensor 7 is
18.degree. C., and the temperature T.sub.s of the division region
60 measured by the temperature sensor 7 is 20.degree. C., the
difference .DELTA.T becomes -2.degree. C. (=18-20).
[0083] Thereafter, the controller 25 determines whether the
absolute value of the difference .DELTA.T is larger than a
predetermined threshold value T.sub.th (S112). The threshold value
T.sub.th is, for example, 0.2.degree. C. When it is determined that
the absolute value of the difference .DELTA.T is not larger than
the threshold value T.sub.th (S112: No), the controller 25 executes
the processing described in S102.
[0084] Meanwhile, when it is determined that the absolute value of
the difference .DELTA.T is larger than the threshold value T.sub.th
(S112: Yes), the controller 25 corrects the temperature T.sub.e
estimated for each of the division regions 60 by the difference
.DELTA.T (S113). Specifically, the controller 25 adds the
difference .DELTA.T to the temperature T.sub.e estimated for each
division region 60, thereby correcting the temperature T.sub.e
estimated for each division region 60. For example, when the
difference .DELTA.T is -2.degree. C., and the temperature T.sub.e
estimated for a certain division region 60 is 20.degree. C., the
controller 25 corrects the temperature T.sub.e estimated for the
division region 60 to 18.degree. C. (=20+(-2)).
[0085] [Experimental Result]
[0086] FIGS. 11A to 11D are views for explaining an effect of
correction by the temperature sensor 7. In the experimental results
illustrated in FIGS. 11A to 11D, a substrate processing apparatus
100 is used in which a first temperature sensor 7 is provided in a
first division region 60, and a second temperature sensor 7 is
provided in a second division region 60 different from the first
division region 60. In the experimental results illustrated in
FIGS. 11A to 11D, the first division region 60 is one division
region 60 included in the third region from the center side among
concentric regions, and the second division region 60 is one
division region 60 included in the fourth region from the center
side among concentric regions. The second temperature sensor 7 is
provided only for this experiment. In FIGS. 11A to 11D, the
temperature of each of the division regions 60 is controlled to be
30.degree. C. The temperature of the refrigerant is 10.degree.
C.
[0087] FIG. 11A illustrates the temperature of the first division
region 60 and the effective value of the AC voltage supplied to the
heater 6c provided in the division region 60 in a case where
correction by the first temperature sensor 7 is not performed. FIG.
11B illustrates the temperature of the first division region 60 and
the effective value of the AC voltage supplied to the heater 6c
provided in the division region 60 in a case where correction by
the first temperature sensor 7 is performed. The temperature of the
first division region 60 is measured by the first temperature
sensor 7.
[0088] In the experimental result of FIG. 11A, the temperature
variation of the first division region 60 falls within a range of
0.53.degree. C., and 3.sigma. indicating the temperature variation
distribution is 0.34.degree. C. In the experimental result of FIG.
11B, the temperature variation of the first division region 60
falls within a range of 0.09.degree. C., and 3.sigma. indicating
the temperature variation distribution is 0.03.degree. C. .sigma.
represents a standard deviation of the temperature variation
distribution.
[0089] FIG. 11C illustrates the temperature of the second division
region 60 and the effective value of the AC voltage supplied to the
heater 6c provided in the division region 60 in a case where
correction by the first temperature sensor 7 is not performed. FIG.
11D illustrates the temperature of the second division region 60
and the effective value of the AC voltage supplied to the heater 6c
provided in the division region 60 in a case where correction by
the first temperature sensor 7 is performed. The temperature of the
second division region 60 is measured by the second temperature
sensor 7.
[0090] In the experimental result of FIG. 11C, the temperature
variation of the second division region 60 falls within a range of
0.51.degree. C., and 3.sigma. indicating the temperature variation
distribution is 0.36.degree. C. In the experimental result of FIG.
11D, the temperature variation of the second division region 60
falls within a range of 0.33.degree. C., and 3.sigma. indicating
the temperature variation distribution is 0.26.degree. C.
[0091] Referring to experimental results of FIGS. 11A and 11C, even
when the correction by the first temperature sensor 7 is not
performed, the temperature variation range of the division region
60 is suppressed to be less than 1.degree. C. Referring to
experimental results of FIGS. 11B and 11D, when the correction by
the first temperature sensor 7 is performed, the temperature
variation range of the division region 60 is further suppressed to
be less than 0.5.degree. C.
[0092] As described above, in the substrate processing system 10
according to the present exemplary embodiment, the temperature
sensor 7 is provided within the base unit 2a corresponding to at
least one division region 60. When a difference equal to or in
larger than a predetermined value occurs between a temperature of
the division region 60 measured by the temperature sensor 7 and a
temperature estimated based on a resistance value of the heater 6c
provided in the division region 60, the controller 25 corrects
temperatures estimated for all division regions 60 based on the
difference. Accordingly, it is possible to control the temperature
of each of the division regions 60 with higher accuracy.
Third Exemplary Embodiment
[0093] In the above described first and second exemplary
embodiments, the conversion table 260 was created in advance and
stored in the holding unit 26. Meanwhile, in the substrate
processing system 10 according to the present exemplary embodiment,
creation of the conversion table 260 is performed.
[0094] FIG. 12 is a sectional view illustrating an example of a
configuration of a substrate processing apparatus 100a when a
conversion table 260 is created. For example, as illustrated in
FIG. 12, when the conversion table 260 is created, the shower head
16 described with reference to FIG. 2 or FIG. 9 is removed from the
chamber 1, and, for example, a calibration unit 50 illustrated in
FIG. 12 is attached to the chamber 1. In FIG. 12, members denoted
by the same reference numerals as those in FIG. 2 or FIG. 9 have
the same or similar functions as the members illustrated in FIG. 2
or FIG. 9 except for the points described below, and thus
descriptions thereof will be omitted.
[0095] The calibration unit 50 includes an infrared (IR) camera 51
and a cover member 52. The cover member 52 supports the IR camera
51 such that the shooting direction of the IR camera 51 faces the
direction of the electrostatic chuck 6. The IR camera 51 measures a
radiation amount distribution of light with a predetermined
wavelength (infrared light in the present exemplary embodiment)
emitted from the top surface of the electrostatic chuck 6. Then,
the IR camera 51 outputs information indicating the measured
radiation amount distribution of the infrared light to the control
device 200.
[0096] [Creation Process of Conversion Table 260]
[0097] FIG. 13 is a flow chart illustrating an example of an
operation of the control device 200 in the third exemplary
embodiment. For example, the control device 200 starts a creation
process of the conversion table 260 illustrated in the flow chart
when an instruction to create the conversion table 260 is received
from, for example, an administrator of the substrate processing
system 10. Information of each setting temperature set in the
conversion table 260 has been stored in advance in the holding unit
26 by, for example, the administrator of the substrate processing
system 10.
[0098] First, the controller 25 selects one of unselected setting
temperatures with reference to the holding unit 26 (S200). In the
present exemplary embodiment, 11 setting temperatures have been
stored in advance in the conversion table 260 in the holding unit
26, at intervals of, for example, 10.degree. C. from 20.degree. C.
to 120.degree. C.
[0099] Thereafter, the controller 25 acquires a temperature of the
division region 60 measured by the temperature sensor 7 (S201).
Then, the controller 25 controls an electric power to be supplied
to the heater 6c of the division region 60 provided with the
temperature sensor 7 so that a difference between the temperature
of the division region 60 provided with the temperature sensor 7,
and the setting temperature selected in step S200 falls within a
predetermined value (e.g., within .+-.0.5.degree. C.) (S202). In
step S202, the controller 25 controls the SW 21 in each power
supply unit 20 so that the same amount of power may be supplied to
each of the heaters 6c in each of the division regions 60, other
than the division region 60 provided with the temperature sensor 7.
The controller 25 controls the chiller unit 33 according to the
setting temperature and adjusts the temperature of the refrigerant
circulated within the base unit 2a.
[0100] After a difference between the temperature of the division
region 60 provided with the temperature sensor 7, and the setting
temperature selected in step S200 falls within a predetermined
value, the IR camera 51 measures a radiation amount distribution of
infrared light emitted from the top surface of the electrostatic
chuck 6 (S203). Then, the IR camera 51 outputs information
indicating the radiation amount distribution of the infrared light
to the control device 200. The controller 25 obtains an average
radiation amount in each of the division regions 60 using
information on the radiation amount distribution of infrared light
output from the IR camera 51 to calculate a radiation amount of
infrared light in each of the division regions 60.
[0101] Subsequently, the controller 25 controls the electric power
to be supplied to each of the heaters 6c so that a difference
between the radiation amount of infrared light from other division
regions 60 not provided with the temperature sensor 7, and the
radiation amount of infrared light from the division region 60
provided with the temperature sensor 7 falls within a predetermined
value (S204). The predetermined value is a value at which a
temperature difference becomes, for example, 0.2.degree. C. when
the difference between infrared light radiation amounts is
converted into a temperature difference.
[0102] After the difference between the radiation amount of
infrared light from other division regions 60 not provided with the
temperature sensor 7, and the radiation amount of infrared light
from the division region 60 provided with the temperature sensor 7
falls within a predetermined value, the measuring unit 24 measures
a resistance value of each of the heaters 6c for each of the
division regions 60 based on an instantaneous value of the AC
current measured by each ammeter 22 and an instantaneous value of
the AC voltage measured by each voltmeter 23 in an intermediate
timing between the adjacent zero-cross points of the AC voltage
(S205). Then, the controller 25 holds the setting temperature
selected in step S200, for each of the division regions 60, in
association with the resistance value of each of the heaters 6c
provided in each of the division regions 60.
[0103] Thereafter, the controller 25 determines whether all setting
temperature have been selected with reference to the holding unit
26 (S206). When it is determined that there is an unselected
setting temperature (S206: No), the controller 25 executes the
processing described in step S200 again.
[0104] Meanwhile, when it is determined that all setting
temperatures have been selected (S206: Yes), the controller 25
creates the conversion table 260 for each of the division regions
60, in which a setting temperature is associated with a resistance
value of each of the heaters 6c (S207). Then, the control device
200 ends the creation process of the conversion table 260
illustrated in the flow chart.
[0105] [Hardware]
[0106] The control device 200 in the above described first to third
exemplary embodiments is implemented using, for example, a computer
90 configured as illustrated in FIG. 14. FIG. 14 is a view
illustrating an example of the computer 90 that implements
functions of the control device 200. The computer 90 includes, a
central processing unit (CPU) 91, a random access memory (RAM) 92,
a read only memory (ROM) 93, an auxiliary storage device 94, a
communication interface (I/F) 95, an input/output interface (I/F)
96, and a media interface (I/F) 97.
[0107] The CPU 91 operates based on a program stored in the ROM 93
or the auxiliary storage device 94 to control respective units. The
ROM 93 stores, for example, a boot program executed by the CPU 91
when the computer 90 is activated or a program dependent on
hardware of the computer 90.
[0108] The auxiliary storage device 94 is, for example, a hard disk
drive (HDD) or a solid state drive (SSD), and stores, for example,
a program executed by the CPU 91 and data used by the program. The
CPU 91 reads the program from the auxiliary storage device 94,
loads the read program on the RAM 92, and executes the loaded
program.
[0109] The communication I/F 95 communicates with the substrate
processing apparatus 100 through a communication line such as a
local area network (LAN). The communication I/F 95 receives data
from the substrate processing apparatus 100 through the
communication line and sends the data to the CPU 91, and transmits
the data generated by the CPU 91 to the substrate processing
apparatus 100 through the communication line.
[0110] The CPU 91 controls an input device such as a keyboard, and
an output device such as a display through the I/O I/F 96. The CPU
91 acquires signals input from the input device through the I/O I/F
96 and sends the acquired signals to the CPU 91. The CPU 91 outputs
the generated data to the output device through the I/O I/F 96.
[0111] The media I/F 97 reads a program or data stored in a
recording medium 98, and stores the read program or data in the
auxiliary storage device 94. The recording medium 98 is, for
example, an optical recording medium such as a digital versatile
disc (DVD) or a phase change rewritable disk (PD), a
magneto-optical recording medium such as a magneto-optical (MO)
disk, a tape medium, a magnetic recording medium, or a
semiconductor memory.
[0112] The CPU 91 of the computer 90 executes a program loaded on
the RAM 92 to implement respective functions of the power supply
unit 20, the measuring unit 24, and the controller 25. The
auxiliary storage device 94 stores data within the holding unit
26.
[0113] The CPU 91 of the computer 90 reads the program to be loaded
on the RAM 92, from the recording medium 98 and stores the read
program in the auxiliary storage device 94. In another example, the
CPU 91 may acquire the program from another device through a
communication line, and store the acquired program in the auxiliary
storage device 94.
[0114] The disclosed technology is not limited to the above
described exemplary embodiments, and various modifications may be
made within the scope of the gist thereof.
[0115] For example, in the above described first exemplary
embodiment, a resistance value of each of the heaters 6c is
measured based on instantaneous values of the AC voltage and the AC
current in an intermediate timing between the adjacent zero-cross
points at which the instantaneous value of the AC voltage supplied
to each of the heaters 6c becomes 0 V. However, the voltage to be
supplied to the heaters 6c is not limited to the AC voltage. For
example, a DC voltage and a DC current may be supplied to the
heaters 6c. In this case, the resistance value of each of the
heaters 6c may be obtained from the DC voltage and the DC current
supplied to each of the heaters 6c.
[0116] In the above described third exemplary embodiment, in the
substrate processing apparatus 100a used for manufacturing a
semiconductor wafer W, the shower head 16 is removed from the
chamber 1, and the calibration unit 50 is attached to the top
portion of the chamber 1. However, the disclosed technology is not
limited thereto. For example, in a manufacturer for manufacturing
the electrostatic chuck 6 and the base unit 2a, the substrate
processing apparatus 100a may be used as a jig for creating the
conversion table 260. In this case, when the conversion table 260
is created, unnecessary functions (for example, the ring magnet 9,
the matchers 11a, and 11b, the high-frequency power supplies 12a
and 12b, the DC power supply 13, and the heat transfer gas supply
unit 31) may not be provided in the substrate processing apparatus
100a.
[0117] In the above described second and third exemplary
embodiments, one temperature sensor 7 is provided in the base unit
2a, but the disclosed technology is not limited thereto. As long as
the number of the temperature sensors 7 is smaller than the number
of the division regions 60, two or more temperature sensors 7 may
be provided in the base unit 2a. Even when two or more temperature
sensors 7 are provided, the electrostatic chuck 6 and the base unit
2a may be miniaturized and the structures thereof may be simplified
as compared to a case where temperature sensors 7 are provided in
all division regions 60, respectively.
[0118] In the above described second exemplary embodiment, when a
difference equal to or larger than a predetermined value occurs
between a temperature T.sub.e estimated from a resistance value of
the heater 6c in the division region 60 provided with the
temperature sensor 7 and a temperature T.sub.s measured by the
temperature sensor 7, temperatures T.sub.e estimated for respective
division regions 60 are corrected based on the difference between
the temperature T.sub.e and the temperature T.sub.s. However, the
disclosed technology is not limited thereto. For example,
temperatures T.sub.e estimated for respective division regions 60
may be corrected based on the difference between the temperature
T.sub.e and the temperature T.sub.s irrespective of the magnitude
of the difference between the temperature T.sub.e and the
temperature T.sub.s.
[0119] In the above described second and third exemplary
embodiments, a fluorescent optical fiber thermometer is exemplified
as the temperature sensor 7, but the disclosed technology is not
limited thereto. As long as the temperature sensor 7 is a sensor
capable of measuring a temperature, the temperature sensor 7 may
be, for example, a thermocouple.
[0120] From the foregoing, it will be appreciated that various
embodiments of the present disclosure have been described herein
for purposes of illustration, and that various modifications may be
made without departing from the scope and spirit of the present
disclosure. Accordingly, the various embodiments disclosed herein
are not intended to be limiting, with the true scope and spirit
being indicated by the following claims.
* * * * *