METHOD OF DETECTING DEVIATION AMOUNT OF SUBSTRATE TRANSPORT POSITION AND SUBSTRATE PROCESSING APPARATUS

A method of detecting a deviation amount of a substrate transport position includes: setting a temperature of a substrate support surface to the same temperature over an entire substrate support surface; etching a first etching target film formed on a substrate; acquiring a first etching rate that is an etching rate of the first etching target film; setting the temperature of the substrate support surface to be concentrically and gradually increased from a central portion to a peripheral edge portion; etching a second etching target film formed on the substrate, the second etching target film being same kind as the first etching target film; acquiring a second etching rate that is an etching rate of the second etching target film; calculating a difference between the acquired first etching rate and second etching rate; and calculating the deviation amount of the substrate transport position based on the calculated difference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority from Japanese Patent Application No. 2021-149088, filed on Sep. 14, 2021 with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to a method of detecting a deviation amount of a substrate transport position, and a substrate processing apparatus.

BACKGROUND

When performing an etching processing in a substrate processing apparatus, an electrostatic chuck (ESC) is periodically replaced because it is consumable. It is known that a replaced ESC contains an error in the installation position thereof, and, therefore, leads to a relative positional deviation between the ESC and a substrate, causing an adverse effect on the properties of the substrate. Against this backdrop, it is known to perform so-called teaching for storing positional coordinates in a controller while visually confirming the transport position of a substrate, in order to correct a relative positional error between a susceptor and the substrate. See, for example, Japanese Patent Laid-Open Publication No. 2000-127069.

SUMMARY

An aspect of the present disclosure relates to a method of detecting a deviation amount of a substrate transport position in a substrate processing apparatus. The substrate processing apparatus includes a process module in which a stage having a substrate support surface is provided inside a chamber, and a controller capable of concentrically controlling a temperature of the substrate support surface. The method includes (a) setting a temperature of the substrate support surface to the same temperature over an entire substrate support surface, (b) etching a first etching target film formed on a substrate disposed on the substrate support substrate, (c) acquiring a first etching rate that is an etching rate of the first etching target film, (d) setting the temperature of the substrate support surface to be concentrically and gradually increased from a central portion to a peripheral edge portion, or to be concentrically and gradually decreased from the central portion to the peripheral edge portion, (e) etching a second etching target film formed on the substrate disposed on the substrate support surface, the second etching target film being the same kind as the first etching target film, (f) acquiring a second etching rate that is an etching rate of the second etching target film, (g) calculating a difference between the first etching rate acquired in (c) and second etching rate acquired in (f), and (h) calculating a deviation amount of the substrate based on the difference calculated in (g).

DESCRIPTION OF EMBODIMENT

Hereinafter, embodiments of a method of detecting the deviation amount of a substrate transport position and a substrate processing apparatus disclosed herein will be described in detail with reference to the drawings. The disclosed technology is not limited by the following embodiments.

As described above, when there is a deviation between the center of an ESC and the center of a substrate, radio frequency (RF) characteristics or temperature characteristics become non-uniform, leading to in-plane non-uniformity in the etching rate or the etching shape. It is difficult to quantify such an error in the relative positions between the ESC and the substrate after assembling them into a chamber. Thus, it is anticipated to accurately and simply detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

[Configuration of Substrate Processing Apparatus]

FIG.1is a cross-sectional plan view illustrating an example of a substrate processing apparatus according to an embodiment of the present disclosure. The substrate processing apparatus1illustrated inFIG.1is a substrate processing apparatus capable of performing various types of processings such as a plasma processing on a single substrate (hereinafter also referred to as a wafer).

As illustrated inFIG.1, the substrate processing apparatus1includes a transfer module10, six process modules20, a loader module30, and two load lock modules40.

The transfer module10has a substantially pentagonal shape in plan view. The transfer module10has a vacuum chamber in which a transport mechanism11is arranged. The transport mechanism11includes a guide rail (not illustrated), two arms12, and a fork13arranged at the tip of each arm12to support the wafer. Each arm12is of a SCARA arm type, and is configured to be pivotable and be freely extendable and retractable. The transport mechanism11moves along the guide rail, and transports the wafer to and from the process modules20or the load lock modules40. The transport mechanism11is not limited to the configuration illustrated inFIG.1as long as it may transport the wafer to and from the process modules20or the load lock modules40. For example, each arm12of the transport mechanism11may be configured to be pivotable and be freely extendable and retractable, and may also be configured to be freely vertically movable.

The process modules20are radially arranged around the transfer module10and are connected to the transfer module10. The process module20is an example of a plasma processing apparatus. The process module20has a processing chamber and includes a cylindrical substrate support21(stage) arranged therein. The substrate support21has a plurality of (e.g., three) thin rod-shaped lift pins22capable of freely protruding from the upper surface thereof. Each lift pin22is arranged on the same circumference in plan view, and is configured to support and lift up the wafer placed on the substrate support21by protruding from the upper surface of the substrate support21and to place the supported wafer on the substrate support21by retracting into the substrate support21. After the wafer is placed on the substrate support21, the inside of the process module20is depressurized, and a processing gas is introduced into the process module20. Furthermore, radio-frequency power is applied to the inside of the process module20to generate a plasma, and the wafer is plasma-processed by the plasma. The transfer module10and the process module20are partitioned by a gate valve23which is able to be freely opened and closed.

The loader module30is arranged to face the transfer module10. The loader module30has a rectangular parallelepiped shape and is an atmospheric transport chamber maintained under an atmospheric pressure environment. Two load lock modules40are connected to one longitudinal side of the loader module30. Three load ports31are connected to the other longitudinal side of the loader module30. A front-opening unified pod (FOUP) (not illustrated), which is a container accommodating a plurality of wafers, is arranged in the load port31. An aligner32is connected to one transverse side of the loader module30. Further, a transport mechanism35is arranged inside the loader module30. Furthermore, a measurement unit38is connected to the other transverse side of the loader module30.

The aligner32performs positioning of the wafer. The aligner32includes a rotary stage33which is rotated by a drive motor (not illustrated). For example, the rotary stage33has a diameter smaller than that of the wafer, and is configured to be rotatable with the wafer placed on the upper surface thereof. An optical sensor34is provided near the rotary stage33to detect the outer peripheral edge of the wafer. In the aligner32, the center position of the wafer and the orientation of a notch with respect to the center of the wafer are detected by the optical sensor34. The wafer is transferred to a fork37to be described later so that the center position of the wafer and the orientation of the notch become a predetermined position and a predetermined orientation. Thus, the transport position of the wafer is adjusted such that the center position of the wafer and the orientation of the notch inside the load lock module40become the predetermined position and the predetermined orientation.

The transport mechanism35includes a guide rail (not illustrated), an arm36, and the fork37. The arm36is of a SCARA arm type, and is configured to be freely movable along the guide rail and also configured to be pivotable, be extendable and retractable, and be freely vertically movable. The fork37is arranged at the tip of the arm36to support the wafer. In the loader module30, the transport mechanism35transports the wafer between the FOUP arranged in each load port31, the aligner32, the measurement unit38, and the load lock modules40. The transport mechanism35is not limited to the configuration illustrated inFIG.1as long as it may transport the wafer among the FOUP, the aligner32, the measurement unit38, and the load lock modules40.

The measurement unit38measures an etching amount with respect to the wafer on which an etching processing has been completed in the process module20. The measurement unit38calculates the etching rate based on the measured etching amount and the time of the etching processing. That is, the measurement unit38measures the etching rate. The measurement unit38outputs the measured etching rate to a control device50to be described later. The measurement unit38is not limited to the position adjacent to the loader module30, and may be arranged inside the loader module30.

The load lock modules40are arranged between the transfer module10and the loader module30. The load lock module40has a variable internal pressure chamber, the inside of which is switchable between the vacuum and the atmospheric pressure, and includes a cylindrical stage41arranged therein. When loading the wafer from the loader module30to the transfer module10, the inside of the load lock module40is maintained at the atmospheric pressure to receive the wafer from the loader module30. Thereafter, the inside of the load lock module40is depressurized to load the wafer into the transfer module10. Further, when unloading the wafer from the transfer module10to the loader module30, the inside of the load lock module40is maintained at the vacuum to receive the wafer from the transfer module10. Thereafter, the inside of the load lock module40is raised to the atmospheric pressure to load the wafer into the loader module30. The stage41has a plurality of (e.g., three) thin rod-shaped lift pins42capable of freely protruding from the upper surface thereof. Each lift pin42is arranged on the same circumference in plan view, and is configured to support and lift up the wafer by protruding from the upper surface of the stage41and to place the supported wafer on the stage41by retracting into the stage41. The load lock module40and the transfer module10are partitioned by a gate valve (not illustrated) which is able to be freely opened and closed. Further, the load lock module40and the loader module30are partitioned by a gate valve (not illustrated) which is able to be freely opened and closed.

The substrate processing apparatus1includes the control device50. The control device50is, for example, a computer, and includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an auxiliary storage device, and the like. The CPU operates based on programs stored in the ROM or the auxiliary storage device, and controls an operation of each component of the substrate processing apparatus1.

[Configuration of Process Module20]

Next, a configuration example of a capacitively-coupled plasma processing apparatus as an example of the process module20will be described. In the following description, the process module20is also referred to as the capacitively-coupled plasma processing apparatus20, or simply referred to as the plasma processing apparatus20.FIG.2is a diagram illustrating an example of a plasma processing apparatus according to the present embodiment.

The capacitively-coupled plasma processing apparatus20includes a plasma processing chamber60, a gas supply70, a power supply80, and an exhaust system90. Further, the plasma processing apparatus20includes the substrate support21and a gas introducer. The gas introducer is configured to introduce at least one processing gas into the plasma processing chamber60. The gas introducer includes a shower head61. The substrate support21is arranged in the plasma processing chamber60. The shower head61is arranged above the substrate support21. In one embodiment, the shower head61constitutes at least a portion of the ceiling of the plasma processing chamber60. The plasma processing chamber60has a plasma processing space60sdefined by the shower head61, a sidewall60aof the plasma processing chamber60, and the substrate support21. The sidewall60ais grounded. The shower head61and the substrate support21are electrically insulated from a housing of the plasma processing chamber60.

The substrate support21includes a main body portion211and a ring assembly212. The main body portion211has a central region (substrate support surface)211afor supporting a wafer (substrate) W and an annular region (ring support surface)211bfor supporting the ring assembly212. The annular region211bof the main body portion21surrounds the central region211aof the main body portion211in plan view. The wafer W is placed on the central region211aof the main body portion211, and the ring assembly212is placed on the annular region211bof the main body portion211so as to surround the wafer W on the central region211aof the main body portion211b. In one embodiment, the main body portion211includes a base and an electrostatic chuck. The base includes a conductive member. The conductive member of the base functions as a lower electrode. The electrostatic chuck is arranged above the base. The upper surface of the electrostatic chuck has the substrate support surface211a. The ring assembly212includes one or a plurality of annular members. At least one of the one or plurality of annular members is an edge ring. Further, although not illustrated, the substrate support21may include a temperature control module configured to control at least one of the electrostatic chuck, the ring assembly212, and the wafer W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. Further, the substrate support21may include a heat transfer gas supply configured to supply a heat transfer gas between the back surface of the wafer W and the substrate support surface211a.

The shower head61is configured to introduce at least one processing gas from the gas supply70into the plasma processing space60s. The shower head61has at least one gas supply port61a, at least one gas diffusion chamber61b, and a plurality of gas introduction ports61c. The processing gas supplied to the gas supply port61apasses through the gas diffusion chamber61band is introduced into the plasma processing space60sfrom the plurality of gas introduction ports61c. The shower head61includes a conductive member. The conductive member of the shower head61functions as an upper electrode. In addition to the shower head61, the gas introducer may include one or a plurality of side gas injectors (SGI) provided in one or a plurality of openings formed in the sidewall60a.

The gas supply70may include at least one gas source71and at least one flow rate controller72. In one embodiment, the gas supply70is configured to supply at least one processing gas from each corresponding gas source71to the shower head61via each corresponding flow rate controller72. Each flow rate controller72may include, for example, a mass flow controller or a pressure-controlled flow rate controller. Further, the gas supply70may include at least one flow rate modulation device that modulates or pulses the flow rate of at least one processing gas.

The power supply80includes an RF power supply81coupled to the plasma processing chamber60via at least one impedance matching circuit. The RF power supply81is configured to supply at least one RF signal (RF power) such as a source RF signal and a bias RF signal to the conductive member of the substrate support21and/or the conductive member of the shower head61. Thus, a plasma is formed from at least one processing gas supplied to the plasma processing space60s. Thus, the RF power supply81may function as at least a part of a plasma generator. Further, when a bias RF signal is supplied to the conductive member of the substrate support21, a bias potential occurs in the wafer W, and ion components in the formed plasma may be drawn to the wafer W.

In one embodiment, the RF power supply81includes a first RF generator81aand a second RF generator81b. The first RF generator81ais coupled to the conductive member of the substrate support21and/or the conductive member of the shower head61via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in a range of 13 MHz to 150 MHz. In one embodiment, the first RF generator81amay be configured to generate a plurality of source RF signals with different frequencies. The generated one or plurality of source RF signals are supplied to the conductive member of the substrate support21and/or the conductive member of the shower head61. The second RF generator81bis coupled to the conductive member of the substrate support21via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in a range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generator81bmay be configured to generate a plurality of bias RF signals with different frequencies. The generated one or plurality of bias RF signals are supplied to the conductive member of the substrate support21. Further, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

Further, the power supply80may include a DC power supply82coupled to the plasma processing chamber60. The DC power supply82includes a first DC generator82aand a second DC generator82b. In one embodiment, the first DC generator82ais connected to the conductive member of the substrate support21, and is configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support21. In one embodiment, the first DC signal may be applied to another electrode such as an electrode in the electrostatic chuck. In one embodiment, the second DC generator82bis connected to the conductive member of the shower head61, and is configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the shower head61. In various embodiments, the first and second DC signals may be pulsed. In addition, the first and second DC generators82aand82bmay be provided in addition to the RF power supply81, and the first DC generator82amay be provided in place of the second RF generator81b.

The exhaust system90may be connected to, for example, a gas outlet60eprovided in a bottom portion of the plasma processing chamber60. The exhaust system90may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space60sis regulated by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof

[Temperature Condition of Etching Processing]

Next, the temperature conditions of an etching processing and the etching rate will be described with reference toFIGS.3to6. First, temperature control regions in the substrate support surface211awill be described with reference toFIGS.3and4.FIG.3is a diagram illustrating an example of temperature control regions of the main body portion of the substrate support according to the present embodiment. As illustrated inFIG.3, the substrate support surface211ais divided into five concentric regions in order from a central portion. The five concentric regions of the substrate support surface211aare designated by C1, C2, M, E, and VE in order from the central portion to a peripheral edge portion. Further, one region of the ring support surface211bis referred to as a region FR because an edge ring such as a focus ring is arranged thereon. The regions C1, C2, M, E, VE, and FR form concentric temperature control regions.

FIG.4is a diagram illustrating an example of a cross section of the main body portion of the substrate support according to the present embodiment. As illustrated inFIG.4, the main body portion211includes a base211cand an electrostatic chuck211d. The electrostatic chuck211dincludes heaters213ato213fcorresponding respectively to the regions C1, C2, M, E, VE, and FR. The heater213ais a circular heater corresponding to the region C1at the central portion of the substrate support surface211a. The heaters213bto213eare annular heaters corresponding to the regions C2, M, E, and VE of the substrate support surface211a. The heater213fis an annular heater corresponding to the region FR of the ring support surface211b. The heaters213ato213feach enable temperature control individually. That is, the control device50is able to control the temperature of the substrate support surface211aand the ring support surface211bconcentrically. The electrostatic chuck211dincludes an attraction electrode (not illustrated). Further, the regions C2, M, E, VE, and FR may be further divided into a plurality of temperature control regions in the circumferential direction. In this case, the heaters213bto213fare also divided so as to correspond to the plurality of divided temperature control regions. Further, the plurality of divided temperature control regions may be controlled to the same temperature in the circumferential direction.

InFIGS.5and6, when etching a silicon nitride film (SiN blanket) formed on the wafer W using a specific recipe that has high temperature sensitivity with respect to the etching rate, the etching rates when the temperature of the wafer W is constant (condition T1) and when the temperature gradient is concentrically formed (condition T1_temp) were acquired.

FIG.5is a diagram illustrating an example of temperature conditions for each etching processing according to the present embodiment. As illustrated inFIG.5, in the condition T1, the shift (x, y) with respect to the transport position of the wafer W in the substrate support surface211ais set to (0, 0). Further, in the condition T1, the temperature of the regions C1, C2, M, E, VE, and FR in the substrate support surface211aand the ring support surface211bis controlled to t1° C.

In the condition T1_temp, the shift (x, y) with respect to the transport position of the wafer W in the substrate support surface211ais set to (0, 0) as in the condition T1. Further, in the condition T1_temp, for each region, the regions C1and C2are controlled to t1° C., the region M is controlled to t2° C., and the regions E and VE are controlled to t3° C. Further, in the condition T1_temp, the region FR in the ring support surface211bis controlled to t3° C. Here, a relationship between the temperatures t1 to t3 is t1<t2<t3. That is, in the condition T1_temp, the temperature gradient is formed concentrically from t1° C. to t3° C. That is, the concentric temperature gradient in the condition T1_temp is a temperature gradient in which the central portion of the wafer W has a lower temperature than the peripheral edge portion. In other words, the concentric temperature gradient is set such that the temperature of the substrate support surface211ais concentrically and gradually increased from the central portion to the peripheral edge portion. The concentric temperature gradient may be a temperature gradient in which the central portion of the wafer W has a higher temperature than the peripheral edge portion. That is, the concentric temperature gradient may be set such that the temperature of the substrate support surface211ais concentrically and gradually decreased from the central portion to the peripheral edge portion. Further, the concentric temperature gradient may be set such that the temperature of the substrate support surface211aand the ring support surface211bis concentrically and gradually increased from the central portion to the peripheral edge portion or the ring support surface211b, or is concentrically and gradually decreased from the central portion to the peripheral edge portion or the ring support surface211b.

The temperature control of the wafer W may be made by controlling at least the temperature of the substrate support surface211a, and the temperature control of the ring support surface211bis not necessarily. The concentric temperature gradient may be formed by at least two temperature regions in the substrate support surface211a, and is not limited to the five temperature regions of the present embodiment. Further, for example, when no heater is embedded in the substrate support21, the surface temperature of the wafer W is controlled to the same temperature by equalizing the pressure of a helium gas, which is a heat transfer gas supplied between the substrate support surface211aand the wafer W, within the substrate support surface211a(placing surface). Meanwhile, the surface temperature of the wafer W is controlled to form the temperature gradient concentrically by varying the pressure of the helium gas between the central portion and the peripheral edge portion in the substrate support surface211a. Further, the temperature of each region may be arbitrarily set such that the temperature gradient is formed within a range that may be set by the main body portion211of the substrate support21, for example, a range of 0° C. to 120° C.

FIG.6is a diagram illustrating an example of a contour map and a graph of the etching rates in the X and Y directions according to the present embodiment.FIG.6illustrates a contour diagram and the etching rates on a straight line in the X and Y directions, which are two different directions, passing through the center of the wafer W, as etching results of the wafer W for the conditions T1 and T1_temp. In the conditions T1 and T1_temp, as an example of the measurement interval of the etching rate, the etching rate was measured at the interval of 5 mm except for the edge portion of the wafer W. In the condition T1, the etching rate is higher at the peripheral edge portion than at the central portion of the wafer W, so that a graph101of the etching rate in the X direction and a graph102of the etching rate in the Y direction may be obtained. The result of the condition T1 contains a deviation caused by the plasma processing chamber60.

Meanwhile, in the condition T1_temp, the etching rate is lower at the peripheral edge portion than at the central portion of the wafer W, so that a graph103of the etching rate in the X direction and a graph104of the etching rate in the Y direction may be obtained. The result of the condition T1_temp contains a deviation caused by the plasma processing chamber60and a deviation caused by the temperature of the substrate support surface211a. The etching rates are not limited to the X and Y directions, and may be those in other directions as long as they include the etching rates in two different directions passing through the center of the wafer W respectively. Further, the etching rates in the two different directions may be the etching rates in two directions perpendicular to each other.

Next, in order to cancel the deviation caused by the plasma processing chamber60, the difference between the etching rates on a straight line in two different directions, i.e., the X and Y directions, passing through the center of the wafer W are calculated.FIG.7is a diagram illustrating an example of a contour map and a graph representing the difference between the etching rates in the X and Y directions according to the present embodiment.

A condition T1Δ illustrated inFIG.7represents the difference between the condition T1 and the condition T1_temp. In the condition T1Δ, a graph105representing the difference between the graph101and the graph103of the etching rates in the X direction, and a graph106representing the difference between the graph102and the graph104of the etching rates in the Y direction may be obtained. The contour map ofFIG.7represents the difference. In the condition T1Δ, the deviation caused by the plasma processing chamber60is canceled, and only the deviation caused by the temperature of the substrate support surface211ais included. That is, since the center of the five concentric circular regions of the substrate support surface211acorresponds to the center of the substrate support surface211a, the graphs105and106of the condition T1Δ represent the deviation amount between the wafer W and the substrate support surface211a. The required accuracy of the deviation amount may be enhanced by shortening the measurement interval of the etching rate.

Here, note specific corresponding ranges107and108(e.g., ±60 to 90 mm) in each section from the center (0 mm) of the wafer W to either peripheral edge portion (150 mm, −150 mm). In the ranges107and108, the graphs105and106are approaching a straight line, so as to correspond to the temperature gradient. Therefore, by obtaining a linear approximate formula for the graphs105and106in the ranges107and108, the center of gravity of contour lines of the contour map may be obtained, and the position of the wafer W relative to the substrate support surface211amay be obtained.

[Calculation of Deviation Amount of Center of Gravity]

FIG.8is a diagram illustrating an example of calculating the deviation amount of the center of gravity by a linear approximate formula from the graph illustrating the difference between the etching rates in the X direction according to the present embodiment. The deviation amount of the center of gravity corresponds to the deviation of the center of gravity of the contour lines of the difference between the etching rates in the contour map illustrated inFIG.7. As illustrated inFIG.8, a graph109is generated by obtaining a linear approximate formula for the range107of the graph105in which the distance from the center of the wafer W is on the positive side. Meanwhile, a graph110is generated by obtaining a linear approximate formula for the range108of the graph105in which the distance from the center of the wafer W is on the negative side.

Next, for the graphs109and110, the value of the x coordinate (Location) when the y coordinate is ΔER=2 [nm/min] was b in the range of Location (60 mm to 90 mm) corresponding to the graph109. Further, the value of the x coordinate (Location) when the y coordinate is ΔER=2 [nm/min] was a in the range of Location (−90 mm to −60 mm) corresponding to the graph110. The center of gravity may be obtained as (a+b)/2 based on the respective values of the x coordinate when the y coordinate is ΔER=2 [nm/min]. That is, when the center of the wafer W is used as a reference, the center of the substrate support surface211adeviates by (a+b)/2 in the X direction.

FIG.9is a diagram illustrating an example of calculating the deviation amount of the center of gravity by a linear approximate formula from the graph illustrating the difference between the etching rates in the Y direction according to the present embodiment. As illustrated inFIG.9, a graph111is generated by obtaining a linear approximate formula for the range107of the graph106in which the distance from the center of the wafer W is on the positive side. Meanwhile, a graph112is generated by obtaining a linear approximate formula for the range108of the graph106in which the distance from the center of the wafer W is on the negative side.

Next, for the graphs111and112, the value of the x coordinate (Location) when the y-coordinate is ΔER=2 [nm/min] was d in the range of Location (60 mm to 90 mm) corresponding to the graph111. Further, the value of the x coordinate (Location) when the y coordinate is ΔER=2 [nm/min] was c in the range of Location (−90 mm to −60 mm) corresponding to the graph112. The center of gravity may be obtained as (c+d)/2 based on the respective values of the x coordinate when the y coordinate is ΔER=2 [nm/min]. That is, when the center of the wafer W is used as a reference, the center of the substrate support surface211adeviates by (c+d)/2 in the Y direction. In the graphs109to112, they coordinate for obtaining the value of the x-coordinate is not limited to ΔER=2 [nm/min], and may use any other value such as ΔER=1 [nm/min] or ΔER=3 [nm/min] as long as it is in a linear region.

FIG.10is a diagram illustrating an example of the deviation amount of the wafer center with respect to the ESC center according to the present embodiment. As illustrated inFIG.10, when expressing the center of a seal band113, which is a portion of the substrate support surface211ain contact with the outermost periphery of the wafer W, as the ESC center (x, y)=(0, 0), the coordinates of the center of the wafer W are obtained based on the center of gravity in each of the X and Y directions, and are expressed as (x, y)=((a+b)/2, (c+d)/2). That is, the deviation amount of the center of the wafer W with respect to the ESC center may be obtained as (x, y)=((a+b)/2, (c+d)/2).

[Method of Detecting Deviation Amount of Substrate Transport Position]

Next, a method of detecting the deviation amount of a substrate transport position in the substrate processing apparatus1according to the present embodiment will be described.FIG.11is a flowchart illustrating an example of a processing of detecting the deviation amount according to the present embodiment. In the following description, an operation of each component of the substrate processing apparatus1is controlled by the control device50. Further, in the process of detecting the deviation amount illustrated inFIG.11will be described as including the adjustment of the substrate transport position based on the detected deviation amount.

The control device50performs control to transport the wafer W accommodated in the FOUP of the load port31to the process module20by way of the loader module30, the load lock module40, and the transfer module10, and to place the wafer W on the substrate support surface211aof the main body portion211. For the measurement of the etching rate, the wafer W is formed with, for example, a silicon nitride film as a first etching target film. The film thickness of the silicon nitride film is previously measured in the X and Y directions which are different two directions.

Thereafter, the control device50closes an opening to control the exhaust system90, thereby discharging a gas from the plasma processing space60sso that the atmosphere in the plasma processing space60sreaches a predetermined degree of vacuum. Further, the control device50controls a temperature control module (not illustrated) such that the temperature of the wafer W is adjusted to the same predetermined temperature. The control device50performs control to supply a process gas to the plasma processing space60s. The process gas may be, for example, a fluorine-containing gas. The control device50performs control to execute a first etching processing of etching the wafer W by a plasma of the process gas generated upon supplying a source RF signal and a bias RF signal from the RF power supply81(step S1). That is, the control device50controls the surface temperature of the wafer W, placed on the substrate support surface211a(stage) of the substrate support21, to the same temperature, so that the first etching target film formed over the wafer W is etched under predetermined conditions.

When the first etching processing is completed, the control device50performs control to stop the supply of the process gas, the source RF signal and the bias RF signal and to open an opening (not illustrated). The control device50performs control to unload the wafer W from the process module20and to transport the wafer W to the measurement unit38by way of the transfer module10, the load lock module40, and the loader module30.

The control device50controls the measurement unit38to measure the film thickness of the silicon nitride film, which is the first etching target film, after the first etching processing. The measurement is performed at the same multiple positions as positions of the previous measurement. The control device50performs control to acquire a first etching rate for the wafer W from the previously measured film thickness of the silicon nitride film and the film thickness of the silicon nitride film after the first etching processing (step S2). The control device50performs control to accommodate the wafer W, for which the first etching rate has been measured, in the FOUP of the load port31by way of the loader module30.

Subsequently, the control device50performs control to transport another wafer W accommodated in the FOUP of the load port31to the process module20by way of the loader module30, the load lock module40, and the transfer module10, and to place the wafer W on the substrate support surface211aof the main body portion211. For the measurement of the etching rate, the other wafer W is also formed with a second etching target film (silicon nitride film), which is the same film as in the first etching processing. The film thickness of the silicon nitride film is previously measured at the same multiple positions in the X and Y directions, which are different two directions. Thereafter, the control device50closes the opening to control the exhaust system90, thereby discharging the gas from the plasma processing space60sso that the atmosphere in the plasma processing space60sreaches a predetermined degree of vacuum.

Further, the control device50controls the temperature control module (not illustrated) such that the temperature of the wafer W is adjusted to a predetermined temperature forming a concentric temperature gradient. That is, the control device50controls the temperature of the substrate support surface211ato be set so as to be concentrically and gradually increased from the central portion to the peripheral edge portion. The control device50performs control to supply a process gas to the plasma processing space60s. The process gas may be, for example, a fluorine-containing gas. The control device50performs control to execute a second etching processing of etching the wafer W by a plasma of the process gas generated upon supplying a source RF signal and a bias RF signal from the RF power supply81(step S3). That is, the control device50controls the surface temperature of the wafer W, placed on the substrate support surface211a(stage) of the substrate support21, to form a concentric temperature gradient, so that the second etching target film of the same kind as the first etching target film, formed on the wafer W, is etched under predetermined conditions.

When the second etching processing is completed, the control device50controls the measurement unit38to measure the film thickness of the silicon nitride film, which is the second etching target film, after the second etching processing as in step S2. The measurement is performed at the same multiple positions as positions of the previous measurement. The control device50performs control to acquire a second etching rate for the other wafer W from the previously measured film thickness of the silicon nitride film and the film thickness of the silicon nitride film after the second etching processing (step S4). The control device50performs control to accommodate the wafer W, for which the second etching rate has been measured, in the FOUP of the load port31by way of the loader module30. When the silicon nitride film of the wafer W used in the first etching processing has a sufficient thickness, the second etching processing may be performed using that wafer W, and the second etching rate may be calculated from the difference between the amounts of etching. Further, the control device50may execute steps S1and S2and steps S3and S4in a reverse order.

The control device50performs control to calculate the difference between the acquired first etching rate and second etching rate for each of the X and Y directions (step S5). That is, the control device50performs control to calculate the difference between the first etching rate and the second etching rate on a straight line in the same direction passing through the center of the wafer W for each of the X and Y directions. The control device50performs control to obtain a linear approximate formula for a specific corresponding range in each section from the center of the wafer W to either peripheral edge portion, for the graph of the difference in each of the X and Y directions (step S6). The control device50performs control to calculate the deviation amount of the wafer W based on the linear approximate formula (step S7). That is, the control device50performs control to calculate, for each of the X and Y directions, the value of the x coordinate corresponding to a specific y coordinate in the graph of the linear approximate formula with respect to the positive side and the negative side of the specific corresponding range, and to obtain, as the deviation amount of the center of gravity of the substrate support surface211a(ESC), a value obtained by dividing the difference between the respective values of the x coordinate by 2. The control device50performs control to calculate the coordinates (deviation amount) of the center of the wafer W at the coordinate axes on the basis of the center of the substrate support surface211aby converting the deviation amount of the center of gravity of the substrate support surface211ain each of the X and Y directions into the deviation amount of the center of gravity of the wafer W.

The control device50performs control to adjust the transport position of the wafer W in the substrate support surface211awhen the transport mechanism11transports the wafer W to the process module20, based on the calculated deviation amount, i.e., the coordinates of the center of the wafer W at the coordinate axes on the basis of the center of the substrate support surface211a(step S8). In this way, in the substrate processing apparatus1, it is possible to detect the relative positional deviation amount between an electrostatic chuck (ESC) and a substrate (wafer W) based on the etching rate when the temperature is constant and the etching rate when the temperature gradient is formed. That is, when the detected deviation amount exceeds a predetermined deviation amount, it is possible to determine whether or not to reassemble the ESC. Further, it is possible to cancel a deviation component of the etching rate (RF deviation, edge ring deviation, or the like) other than those caused by the relative positions between the ESC and the wafer W. Furthermore, it is possible to adjust the substrate transport position without opening the plasma processing chamber60to the atmosphere during an operation of the substrate processing apparatus1.

The above embodiment has employed the etching rate of the silicon nitride film formed on the wafer W, but is not limited thereto. The etching rate may be the etching rate of a film having high temperature sensitivity, and for example, may employ the etching rate of a silicon containing film or an organic film. An example of the silicon containing film may include a silicon oxide film in addition to the silicon nitride film described above. Further, an example of the organic film may include a carbon containing film such as a resist.

As described above, according to the present embodiment, the substrate processing apparatus1includes the process module20in which a stage (main body portion211) having the substrate support surface211ais provided inside a chamber (plasma processing chamber60), the measurement unit38configured to measure the etching rate of a substrate (wafer W), and a controller (control device50) capable of concentrically controlling the temperature of the substrate support surface211a. (a) The controller is configured to control the substrate processing apparatus1so as to set a temperature of the substrate support surface211ato the same temperature over the entire substrate support surface211a. (b) The controller is configured to control the substrate processing apparatus1so as to etch a first etching target film formed on the substrate. (c) The controller is configured to control the substrate processing apparatus1so as to acquire a first etching rate that is an etching rate of the first etching target film. (d) The controller is configured to control the substrate processing apparatus1so as to set the temperature of the substrate support surface to be concentrically and gradually increased from a central portion to a peripheral edge portion, or to be concentrically and gradually decreased from the central portion to the peripheral edge portion. (e) The controller is configured to to control the substrate processing apparatus1so as to etch a second etching target film formed on the substrate, the second etching target film being the same kind as the first etching target film. (f), the controller is configured to control the substrate processing apparatus1so as to acquire a second etching rate that is an etching rate of the second etching target film. (g) The controller is configured to control the substrate processing apparatus1so as to calculate a difference between the acquired first etching rate and second etching rate. (h) The controller is configured to control the substrate processing apparatus1so as to calculate a deviation amount of the substrate transport position based on the calculated difference. As a result, it is possible to detect the deviation amount of the relative position between an electrostatic chuck (main body portion211) and the substrate. Further, it is possible to cancel a deviation of the etching rate other than those caused by the relative positions between the electrostatic chuck and the wafer W.

Further, according to the present embodiment, each of the first etching rate and the second etching rate include etching rates in two different directions passing through a center of the substrate. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, the etching rates in the two different directions are etching rates in two directions perpendicular to each other. As a result, it is possible to detect the deviation amount of relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, (g) includes calculating each difference between the first etching rate and the second etching rate on a straight line in the same direction passing through the center of the substrate, and (h) includes obtaining each linear approximate formula for a specific corresponding range in each section from the center of the substrate to either peripheral edge portion when each difference on the straight line is represented by a graph, and calculating the deviation amount based on each linear approximate formula. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, the substrate support surface has at least two concentric temperature control regions. As a result, it is possible to obtain the difference between the first etching rate and the second etching rate.

Further, according to the present embodiment, the stage has the annular ring support surface211bon the outer peripheral side of the substrate support surface. (a) includes setting the temperature of the substrate support surface and the temperature of the ring support surface to the same temperature, and (d) includes setting the temperature of the substrate support surface and the ring support surface to be concentrically and gradually increased from the central portion to the peripheral edge portion or the ring support surface211b, or to be concentrically and gradually decreased from the central portion to the peripheral portion or the ring support surface211b. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, the first etching rate and the second etching rate are etching rates of a silicon containing film or an organic film formed on the substrate. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, the silicon containing film is a silicon nitride film or a silicon oxide film. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

Further, according to the present embodiment, (i) the controller is configured to control the substrate processing apparatus1so as to adjust the substrate transport position based on the calculated deviation amount. As a result, it is possible to adjust the substrate transport position accurately and easily.

Further, according to the present embodiment, the first etching rate and the second etching rate are acquired by being measured in the measurement unit38. As a result, it is possible to detect the deviation amount of the relative position between the electrostatic chuck and the substrate.

In each embodiment described above, the measurement unit38is provided in the substrate processing apparatus1, but is not limited thereto. For example, a measurement device independent of the substrate processing apparatus1may be used to measure and acquire the film thickness before and after an etching processing for the measurement of the etching rate.

Further, in the embodiment described above, the process module20that performs a processing such as etching on the wafer W using a capacitively coupled plasma as a plasma source has been described by way of example, but the disclosed technology is not limited thereto. The plasma source is not limited to the capacitively coupled plasma as long as it is a device that performs a processing on the wafer W using a plasma, and may employ any plasma source such as inductively coupled plasma, microwave plasma, or magnetron plasma.

According to the present disclosure, it is possible to detect the deviation amount of the relative position between an electrostatic chuck and a substrate.