SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE TRANSPORT POSITION ADJUSTING METHOD

Abstract

To accurately and easily adjust a substrate conveyance position.SOLUTION: A substrate processing device comprises: a process module provided within a chamber and including a mount table including a first mount surface on which a substrate is mounted and a second mount surface disposed in an outer periphery of the first mount surface, and an edge ring mounted on the second mount surface; a measurement unit for measuring an etching rate of the substrate; and a control unit. The control unit conveys the substrate to different conveyance positions on the first mount surface on a specific processing condition, performs control to etch the substrate for each conveyance position, acquires the etching rates at a plurality of points on a circle concentric with the substrate in the vicinity of an end of the substrate from the measurement unit for each conveyance position, generates an approximate curve of each concentric circle in a circumferential direction based on each acquired etching rate for each conveyance position, calculates linear expressions representing a moving direction of the substrate based on the generated approximate curve for each conveyance position, and calculates intersection coordinates of the calculated linear expressions.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing apparatus and a substrate transfer position adjusting method. [Background technology]

[0002] When performing an etching process in a substrate processing apparatus, the edge ring placed around the substrate to be processed is replaced periodically due to wear. It is known that the replaced edge ring includes an error in the installation position, which leads to a deviation in the relative position between the edge ring and the substrate, and has a significant adverse effect on the characteristics of the outer periphery of the substrate. In response to this, it is known that in order to correct the error in the relative position between the edge ring and the substrate, a so-called teaching is performed in which the position coordinates of the substrate are stored in a control unit while visually checking the transport position of the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-127069 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a substrate processing apparatus and a substrate transfer position adjusting method that can accurately and easily adjust a substrate transfer position. [Means for solving the problem]

[0005] A substrate processing apparatus according to one embodiment of the present disclosure includes a process module provided inside a chamber, the process module including a mounting table having a first mounting surface on which a substrate is mounted and a second mounting surface arranged on an outer periphery of the first mounting surface, and an edge ring mounted on the second mounting surface, a measurement unit for measuring an etching rate of the substrate, and a control unit, wherein the control unit is configured to control the substrate processing apparatus to transport the substrate to different transport positions on the first mounting surface under specific processing conditions and to etch the substrate for each transport position, the control unit is configured to control the substrate processing apparatus to obtain, for each transport position, etching rates at multiple points on a concentric circle with respect to the substrate near an end of the substrate from the measurement unit, the control unit is configured to control the substrate processing apparatus to generate respective approximation curves in the circumferential direction of the concentric circle based on each of the obtained etching rates for each transport position, the control unit is configured to control the substrate processing apparatus to calculate respective linear equations representing the movement direction of the substrate based on the generated approximation curves for each transport position, and the control unit is configured to control the substrate processing apparatus to calculate the intersection coordinates of each calculated linear equation. Effect of the Invention

[0006] According to the present disclosure, the substrate transport position can be adjusted accurately and easily. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional plan view showing an example of a substrate processing apparatus according to a first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram illustrating an example of the plasma processing apparatus according to the first embodiment. [Diagram 3] FIG. 3 is a contour diagram showing an example of a case where the wafer is misaligned. [Figure 4] FIG. 4 is a diagram showing an example of generation of an approximation curve of an etching rate. [Diagram 5] FIG. 5 is a diagram showing an example of teaching using an approximation curve. [Figure 6]FIG. 6 is a diagram showing an example in which an operator performs teaching. [Figure 7] FIG. 7 is a diagram illustrating an example of parameters in the sine approximation method. [Figure 8] FIG. 8 is a graph showing an example of the relationship between the movement amount of the wafer and the etching rate in the first embodiment. [Figure 9] FIG. 9 is a graph showing an example of the relationship between the movement amount of the wafer and the uniformity in the first embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of the transport position adjustment process in the first embodiment. [Figure 11] FIG. 11 is a graph showing an example of the relationship between the movement amount of the wafer and the etching rate in the second embodiment. [Figure 12] FIG. 12 is a graph showing an example of the relationship between the movement amount of the wafer and the uniformity in the second embodiment. [Figure 13] FIG. 13 is a diagram showing an example of linear equations representing the movement direction and the intersection coordinates of each linear equation in the second embodiment. [Figure 14] FIG. 14 is a flowchart showing an example of the transport position adjustment process in the second embodiment. [Figure 15] FIG. 15 is a diagram showing an example of a result of teaching in the second embodiment. [Figure 16] FIG. 16 is a diagram showing an example of a result of teaching in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a substrate processing apparatus and a substrate transfer position adjusting method will be described in detail with reference to the accompanying drawings. Note that the disclosed technology is not limited to the following preferred embodiments.

[0009] As teaching, in addition to a method of visually adjusting the transport position, there is a method of adjusting the transport position based on process characteristics such as etching rate, so-called etch rate teaching. In conventional etch rate teaching, an operator manually adjusts the transport position according to the process characteristics. However, it is difficult to quantitatively calculate an appropriate adjustment amount with these methods. Therefore, there are cases where the adjustment accuracy is poor or the adjustment requires a lot of labor. Therefore, it is expected that the substrate transport position can be adjusted accurately and easily. Although the teaching of the present disclosure relates to etch rate teaching, hereinafter it will be simply called teaching.

[0010] (First embodiment) [Configuration of substrate processing equipment] Fig. 1 is a cross-sectional plan view showing an example of a substrate processing apparatus according to a first embodiment of the present disclosure. The substrate processing apparatus 1 shown in Fig. 1 is a substrate processing apparatus capable of performing various processes such as plasma processing on substrates (hereinafter also referred to as wafers) one by one.

[0011] As shown in FIG. 1, the substrate processing apparatus 1 includes a transfer module 10, six process modules 20, a loader module 30, and two load lock modules 40.

[0012] The transfer module 10 has a substantially pentagonal shape in a plan view. The transfer module 10 has a vacuum chamber, and a transfer mechanism 11 is disposed inside. The transfer mechanism 11 has a guide rail (not shown), two arms 12, and a fork 13 disposed at the tip of each arm 12 to support a wafer. Each arm 12 is a SCARA arm type and is configured to be rotatable and extendable. The transfer mechanism 11 moves along the guide rail and transfers a wafer between the process module 20 and the load lock module 40. Note that the transfer mechanism 11 is not limited to the configuration shown in FIG. 1 as long as it is capable of transferring a wafer between the process module 20 and the load lock module 40. For example, each arm 12 of the transfer mechanism 11 may be configured to be rotatable, extendable, and movable up and down.

[0013] The process modules 20 are arranged radially around the transfer module 10 and connected to the transfer module 10. The process module 20 is an example of a plasma processing apparatus. The process module 20 has a processing chamber and a cylindrical substrate support part 21 (mounting table) arranged inside. The substrate support part 21 has three lift pins 22 in the form of a thin rod that can be freely protruded from the upper surface. Each lift pin 22 is arranged on the same circumference in a plan view, and supports and lifts a wafer placed on the substrate support part 21 by protruding from the upper surface of the substrate support part 21, and places the supported wafer on the substrate support part 21 by retracting into the substrate support part 21. After the wafer is placed on the substrate support part 21, the process module 20 reduces the pressure inside to introduce a processing gas, and further applies high-frequency power inside to generate plasma, and performs plasma processing on the wafer by the plasma. The transfer module 10 and the process module 20 are separated by a gate valve 23 that can be freely opened and closed.

[0014] The loader module 30 is disposed opposite the transfer module 10. The loader module 30 is a rectangular parallelepiped and is an atmospheric transfer chamber maintained in an atmospheric pressure atmosphere. Two load lock modules 40 are connected to one side surface along the longitudinal direction of the loader module 30. Three load ports 31 are connected to the other side surface along the longitudinal direction of the loader module 30. A FOUP (Front-Opening Unified Pod) (not shown), which is a container for accommodating a plurality of wafers, is placed on the load port 31. An aligner 32 is connected to one side surface along the transverse direction of the loader module 30. A transfer mechanism 35 is disposed within the loader module 30. Furthermore, a measurement unit 38 is connected to the other side surface along the transverse direction of the loader module 30.

[0015] The aligner 32 aligns the wafer. The aligner 32 has a rotary stage 33 rotated by a drive motor (not shown). The rotary stage 33 has a diameter smaller than that of the wafer, for example, and is configured to be rotatable with the wafer placed on the upper surface. An optical sensor 34 for detecting the outer periphery of the wafer is provided near the rotary stage 33. In the aligner 32, the optical sensor 34 detects the center position of the wafer and the direction of the notch relative to the center of the wafer, and the wafer is transferred to a fork 37 (described later) so that the center position of the wafer and the direction of the notch are at a predetermined position and in a predetermined direction. As a result, the transport position of the wafer is adjusted in the load lock module 40 so that the center position of the wafer and the direction of the notch are at a predetermined position and in a predetermined direction.

[0016] The transfer mechanism 35 has a guide rail (not shown), an arm 36, and a fork 37. The arm 36 is a SCARA arm type, and is configured to be freely movable along the guide rail, and is also configured to be freely rotatable, extendable, and movable up and down. The fork 37 is disposed at the tip of the arm 36 and supports the wafer. In the loader module 30, the transfer mechanism 35 transfers the wafer between the FOUPs placed on each load port 31, the aligner 32, the measurement unit 38, and the load lock module 40. Note that the transfer mechanism 35 is not limited to the configuration shown in FIG. 1 as long as it is capable of transferring the wafer between the FOUPs, the aligner 32, the measurement unit 38, and the load lock module 40.

[0017] The measuring unit 38 measures the etching amount of the wafer after the etching process in the process module 20. The measuring unit 38 calculates the etching rate based on the measured etching amount and the etching process time. That is, the measuring unit 38 measures the etching rate. The measuring unit 38 outputs the measured etching rate to the control device 50 described later. The measuring unit 38 is not limited to being located adjacent to the loader module 30, and may be located inside the loader module 30.

[0018] The load lock module 40 is disposed between the transfer module 10 and the loader module 30. The load lock module 40 has an internal pressure variable chamber that can be switched between vacuum and atmospheric pressure, and has a cylindrical stage 41 disposed therein. When the load lock module 40 carries a wafer from the loader module 30 to the transfer module 10, the load lock module 40 maintains the internal pressure at atmospheric pressure, receives the wafer from the loader module 30, and then reduces the internal pressure to carry the wafer into the transfer module 10. When the load lock module 40 carries a wafer from the transfer module 10 to the loader module 30, the load lock module 40 maintains the internal pressure at vacuum, receives the wafer from the transfer module 10, and then increases the internal pressure to atmospheric pressure to carry the wafer into the loader module 30. The stage 41 has three lift pins 42 in the form of a plurality of thin rods that can be freely protruded from the upper surface. The lift pins 42 are arranged on the same circumference in a plan view, and support and lift the wafer by protruding from the upper surface of the stage 41, and place the supported wafer on the stage 41 by retracting into the stage 41. The load lock module 40 and the transfer module 10 are separated by a gate valve (not shown) that can be opened and closed freely. The load lock module 40 and the loader module 30 are also separated by a gate valve (not shown) that can be opened and closed freely.

[0019] The substrate processing apparatus 1 includes a control device 50. The control device 50 is, for example, a computer, and includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an auxiliary storage device, etc. The CPU operates based on a program stored in the ROM or the auxiliary storage device, and controls the operation of each component of the substrate processing apparatus 1.

[0020] [Process module 20 configuration] Next, a configuration example of a capacitively coupled plasma processing apparatus will be described as an example of the process module 20. In the following description, the process module 20 will be referred to as a capacitively coupled plasma processing apparatus 20 or simply as a plasma processing apparatus 20. Fig. 2 is a diagram showing an example of a plasma processing apparatus in the first embodiment.

[0021] The capacitively coupled plasma processing apparatus 20 includes a plasma processing chamber 60, a gas supply 70, a power supply 80, and an exhaust system 90. The plasma processing apparatus 20 also includes a substrate support 21 and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 60. The gas inlet includes a showerhead 61. The substrate support 21 is disposed in the plasma processing chamber 60. The showerhead 61 is disposed above the substrate support 21. In one embodiment, the showerhead 61 forms at least a portion of a ceiling of the plasma processing chamber 60. The plasma processing chamber 60 has a plasma processing space 60s defined by the showerhead 61, a sidewall 60a of the plasma processing chamber 60, and the substrate support 21. The sidewall 60a is grounded. The showerhead 61 and the substrate support 21 are electrically insulated from a plasma processing chamber 60 housing.

[0022] The substrate support 21 includes a main body 211 and a ring assembly 212. The main body 211 has a central region (substrate support surface) 211a for supporting a wafer (substrate) W, and an annular region (ring support surface) 211b for supporting the ring assembly 212. The annular region 211b of the main body 211 surrounds the central region 211a of the main body 211 in a plan view. The wafer W is disposed on the central region 211a of the main body 211, and the ring assembly 212 is disposed on the annular region 211b of the main body 211 so as to surround the wafer W on the central region 211a of the main body 211. In one embodiment, the main body 211 includes 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 disposed on the base. The upper surface of the electrostatic chuck has a substrate support surface 211a. The ring assembly 212 includes one or more annular members. At least one of the one or more annular members is an edge ring. Although not shown, the substrate support 21 may include a temperature adjustment module configured to adjust at least one of the electrostatic chuck, the ring assembly 212, and the wafer W to a target temperature. The temperature adjustment 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. The substrate support 21 may also include a heat transfer gas supply unit configured to supply a heat transfer gas between the back surface of the wafer W and the substrate support surface 211a.

[0023] The shower head 61 is configured to introduce at least one processing gas from the gas supply unit 70 into the plasma processing space 60s. The shower head 61 has at least one gas supply port 61a, at least one gas diffusion chamber 61b, and multiple gas inlets 61c. The processing gas supplied to the gas supply port 61a passes through the gas diffusion chamber 61b and is introduced into the plasma processing space 60s from the multiple gas inlets 61c. The shower head 61 also includes a conductive member. The conductive member of the shower head 61 functions as an upper electrode. In addition to the shower head 61, the gas introduction unit may include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 60a.

[0024] The gas supply 70 may include at least one gas source 71 and at least one flow controller 72. In one embodiment, the gas supply 70 is configured to supply at least one process gas from a respective gas source 71 through a respective flow controller 72 to the showerhead 61. Each flow controller 72 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 70 may include at least one flow modulation device to modulate or pulse a flow rate of the at least one process gas.

[0025] The power source 80 includes an RF power source 81 coupled to the plasma processing chamber 60 via at least one impedance matching circuit. The RF power source 81 is 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 support 21 and / or the conductive member of the showerhead 61. This causes plasma to be formed from at least one processing gas supplied to the plasma processing space 60s. Thus, the RF power source 81 can function as at least a part of the plasma generating unit. In addition, by supplying a bias RF signal to the conductive member of the substrate support 21, a bias potential is generated on the wafer W, and ion components in the formed plasma can be attracted to the wafer W.

[0026] In one embodiment, the RF power supply 81 includes a first RF generating unit 81a and a second RF generating unit 81b. The first RF generating unit 81a is coupled to the conductive member of the substrate support 21 and / or the conductive member of the shower head 61 via 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 the range of 13 MHz to 150 MHz. In one embodiment, the first RF generating unit 81a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the conductive member of the substrate support 21 and / or the conductive member of the shower head 61. The second RF generating unit 81b is coupled to the conductive member of the substrate support 21 via 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 the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generator 81b may be configured to generate multiple bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the conductive members of the substrate support 21. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0027] The power supply 80 may also include a DC power supply 82 coupled to the plasma processing chamber 60. The DC power supply 82 includes a first DC generator 82a and a second DC generator 82b. In one embodiment, the first DC generator 82a is connected to a conductive member of the substrate support 21 and configured to generate a first DC signal. The generated first DC signal is applied to the conductive member of the substrate support 21. In one embodiment, the first DC signal may be applied to another electrode, such as an electrode in an electrostatic chuck. In one embodiment, the second DC generator 82b is connected to a conductive member of the showerhead 61 and configured to generate a second DC signal. The generated second DC signal is applied to the conductive member of the showerhead 61. In various embodiments, the first and second DC signals may be pulsed. The first and second DC generating units 82a, 82b may be provided in addition to the RF power supply 81, or the first DC generating unit 82a may be provided in place of the second RF generating unit 81b.

[0028] The exhaust system 90 may be connected to, for example, a gas exhaust port 60e provided at the bottom of the plasma processing chamber 60. The exhaust system 90 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 60s is adjusted by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0029] Calculate travel direction Next, the calculation of the moving direction of the wafer W will be described with reference to FIG. 3 to FIG. 7. FIG. 3 is a contour diagram showing an example of a case where the wafer is misaligned. The contour diagram shown in FIG. 3 shows sampling numbers "1" to "40" set on the circumference of the outer periphery of the wafer W and the etching rate of the oxide film (Ox). The sampling numbers are set at equal intervals on a circumference of a radius of 147 mm that is concentric with the wafer W. In the example of FIG. 3, it can be seen that the etching rate is slow near the sampling number "36" and the etching rate is fast near the sampling number "18". The relationship between the etching rate and the position of the wafer W is that the faster the etching rate, the farther the wafer W is from the edge ring. It is preferable that the concentric circle on which the sampling numbers are set is within a distance of 30 mm from the edge of the wafer W.

[0030] FIG. 4 is a diagram showing an example of generation of an approximation curve of an etching rate. As shown in FIG. 4, a graph 101 is a graph plotting raw data of the etching rate of sampling numbers "1" to "40" set in FIG. 3. The graph 101 includes noise due to factors other than the horizontal position of the wafer W, such as the vertical position and particles. The graph 102 is a graph obtained by performing a smoothing process on the graph 101 using a moving average of three points. The graph 103 is a graph obtained by performing fitting on the graph 102 using a sine approximation to generate an approximation curve. In the graph 103, the direction corresponding to the sampling number in which the etching rate is maximum is the direction in which the edge ring and the wafer W are most distant from each other. In other words, the direction in which the etching rate is maximum is the direction in which the wafer W should be moved.

[0031] Fig. 5 is a diagram showing an example of teaching using an approximation curve. In the graph 103 of Fig. 4, the direction in which the etching rate is maximum is the direction of sampling number "12". Therefore, the moving direction of the wafer W becomes the direction of sampling number "12" by one teaching, as shown by vector 104 of Fig. 5. The amount of movement is unknown from the graph 103.

[0032] FIG. 6 is a diagram showing an example of a case where an operator performs teaching. On the other hand, when an operator performs teaching, since the etching rate of sampling number "18" is the maximum in graph 101 of FIG. 4, the transport position of the wafer W is adjusted to move by 0.2 mm in the direction of sampling number "18" as shown by vector 105 in FIG. 6 as the first time. After that, an etching process is performed, and the etching rates of sampling numbers "1" to "40" are measured and plotted in the same manner as in graph 101, and it is assumed that the etching rate of sampling number "3" is the maximum. As a second time, the operator adjusts the transport position of the wafer W to move by 0.1 mm in the direction of sampling number "3" as shown by vector 106. Thereafter, similarly, an etching process is performed after the adjustment, and the operator adjusts by 0.05 mm in the direction of sampling number "11" as shown by vector 107 as the third time and by vector 108 as the fourth time. As a result of the operator teaching four times, the wafer W moves 0.237 mm in the direction of sampling number "13" indicated by vector 109, which is a combination of vectors 105 to 108. In this way, for vector 104 in FIG. 5 using sine approximation, the direction of sampling number "12" can be determined with one teaching, but if the operator does it, teaching will have to be performed four times to find vector 109. In other words, when sine approximation is used, the movement direction can be calculated with one teaching, without unnecessary movements due to noise in the etching rate.

[0033] Next, the generation of an approximation curve by sine approximation will be described in detail. In the sine approximation, the following formula (1) is used.

[0034] y = a sin b ( x + c ) + d (1)

[0035] Here, parameter a indicates the amplitude of the sine wave, that is, the bias of the etching rate. Parameter a corresponds approximately to the movement amount of the wafer W. Parameter b indicates the period of the sine wave, and is fixed to "1" since only the planar bias between the edge ring and the wafer W is taken into consideration, that is, one circumference of the circumference of the sample is sufficient. Parameter c indicates the phase of the sine wave, and indicates the bias direction of the wafer W. Parameter c corresponds approximately to the movement direction of the wafer W. Parameter d indicates the offset, and is fixed to the average etching rate of sampling numbers "1" to "40". Note that by fixing parameters b and d, it is possible to prevent the solution of the simultaneous equations from diverging or falling into a local optimum solution.

[0036] FIG. 7 is a diagram showing an example of parameters in the sine approximation method. Table 110 shown in FIG. 7 shows some of the parameters when sine approximation is performed using a solver that calculates optimal values ​​while changing the values ​​of multiple variables in a spreadsheet software. The "Sampling No." column shows the above-mentioned sampling number, and a value expressed in radians is used when substituting for x. The "ER" column shows the actual measured value of the etching rate at the corresponding sampling number (unit: "nm"). The "Approximation" column shows x corresponding to the sampling number, which corresponds to formula (1), and y which is the approximate value of the etching rate when any value is entered into parameters a and c. The "Square error" column shows the square error between the approximate value and the actual measured value. The solver finds parameters a and c that minimize the sum of square errors represented by "Sum (square error)" for 40 rows corresponding to sampling numbers "1" to "40" in table 110. Note that other algorithms may be used as long as they find solutions to the simultaneous equations of equation (1) corresponding to sampling numbers "1" to "40," that is, they perform sine approximation by varying parameters a and c.

[0037] [Calculation of movement amount 1] FIG. 8 is a graph showing an example of the relationship between the movement amount of the wafer W and the etching rate in the first embodiment. Graph 111 shown in FIG. 8 is a graph showing an example of the relationship when the correlation between the movement amount of the wafer W and the etching rate is simple. Graph 111 shows the change in the etching rate when the movement amount of the wafer W per teaching is 0.05 mm and four teachings are tried. In the first teaching, when the wafer W is moved 0.05 mm from the initial position, the etching rate changes by -0.2 nm / min. In the second teaching, when the wafer W is moved 0.05 mm from the first position, the etching rate changes by -0.2 nm / min. Similarly, in the third and fourth teachings, when the wafer W is moved 0.05 mm from the previous position, the etching rate changes by -0.2 nm / min. In other words, in the example of graph 111, the change in the etching rate per movement amount of the wafer W is constant.

[0038] FIG. 9 is a graph showing an example of the relationship between the movement amount of the wafer and the uniformity in the first embodiment. Graph 112 shown in FIG. 9 is a graph showing an example of the relationship when the correlation between the movement amount of the wafer W and the uniformity is simple. Here, the uniformity represents the uniformity of the etching rate and corresponds to the amplitude of the sine approximation curve. Graph 112 is a graph in which the uniformity for every 0.1 mm of the movement amount is plotted from 0 mm to 0.4 mm, and the change in the uniformity is linear. When the relationship shown in graph 111 or graph 112 is recognized, a database showing the relationship between the movement amount and the etching rate, or the relationship between the movement amount and the amplitude (uniformity) of the approximation curve is created in advance. If teaching is performed once to obtain the etching rate, the movement amount of the wafer W can be calculated from the change amount or uniformity of the etching rate by referring to the database created in advance.

[0039] [Transport position adjustment method] Next, a method for adjusting the transfer position in the substrate processing apparatus 1 of the first embodiment will be described. Fig. 10 is a flow chart showing an example of a transfer position adjustment process in the first embodiment. In the following description, the operation of each component of the substrate processing apparatus 1 is controlled by a control device 50.

[0040] The control device 50 transports the wafer W accommodated in the FOUP of the load port 31 to the process module 20 via the loader module 30, the load lock module 40, and the transfer module 10, and places the wafer W on the substrate support surface 211a of the main body 211. Note that, for example, a silicon oxide film (SiO2) is formed on the wafer W in order to measure the etching rate.

[0041] The controller 50 then closes the opening and controls the exhaust system 90 to exhaust gas from the plasma processing space 60s so that the atmosphere in the plasma processing space 60s has a predetermined vacuum degree. The controller 50 also controls a temperature control module (not shown) to adjust the temperature of the wafer W to a predetermined temperature. The controller 50 starts supplying a process gas, and the process gas is filled into the plasma processing space 60s. The process gas may be, for example, a fluorine-containing gas. The controller 50 supplies a source RF signal and a bias RF signal from the RF power source 81 to generate a plasma of the process gas, and performs an etching process on the wafer W (step S1).

[0042] When the etching process is completed, the control device 50 stops the supply of the process gas, the source RF signal, and the bias RF signal, and opens the opening (not shown). The control device 50 unloads the wafer W from the process module 20, and transports it to the measurement unit 38 via the transfer module 10, the load lock module 40, and the loader module 30.

[0043] The control device 50 measures and acquires the etching rate on the concentric circle of the outer periphery of the wafer W in the measurement unit 38 (step S2). The control device 50 generates a sine approximation curve in the circumferential direction of the concentric circle based on the acquired etching rate (step S3). The control device 50 determines the movement direction of the wafer W based on the generated sine approximation curve (step S4).

[0044] The control device 50 refers to a database showing the relationship between the movement amount and the etching rate, or the relationship between the movement amount and the uniformity (the amplitude of the sine approximation curve), and calculates the movement amount of the wafer W in the determined movement direction (step S5). Based on the determined movement direction and the calculated movement amount, the control device 50 adjusts the transfer position of the wafer W on the substrate support surface 211a when the transfer mechanism 11 transfers the wafer W to the process module 20 (step S6). In this way, in the substrate processing apparatus 1 of the first embodiment, the movement direction and movement amount of the wafer W are determined based on the etching rate, so that the substrate transfer position can be adjusted accurately and easily. In addition, the maintenance time can be shortened. Furthermore, even during operation of the substrate processing apparatus 1, the substrate transfer position can be adjusted without opening the plasma processing chamber 60 to the atmosphere.

[0045] Second embodiment In the above-mentioned first embodiment, when the correlation between the movement amount and the etching rate is simple, the movement amount of the wafer W is calculated by referring to a database created in advance, but when the correlation between the movement amount and the etching rate is complex, it is difficult to create a database. In this case, the transfer position may be intentionally shifted to obtain the etching rate twice to calculate the movement direction and movement amount of the wafer W, and this embodiment will be described as the second embodiment. Note that the configuration of the substrate processing apparatus in the second embodiment is the same as that of the first embodiment, so the description of the overlapping configuration and operation will be omitted.

[0046] [Calculation of movement amount 2] FIG. 11 is a graph showing an example of the relationship between the movement amount of the wafer W and the etching rate in the second embodiment. Graph 113 shown in FIG. 11 is a graph showing an example of the relationship when the correlation between the movement amount of the wafer W and the etching rate is complicated. Graph 113 shows the change in the etching rate when the movement amount of the wafer W per teaching is 0.05 mm and four teachings are tried. In the first teaching, when the wafer W is moved 0.05 mm from the initial position, the change in the etching rate is 0.0 nm / min, which is almost no change. In the second teaching, when the wafer W is moved 0.05 mm from the first position, the etching rate changes by -0.37 nm / min. In the third teaching, when the wafer W is moved 0.05 mm from the second position, the etching rate changes by -0.14 nm / min. In the fourth teaching, when the wafer W is moved 0.05 mm from the third position, the etching rate changes by -0.51 nm / min. That is, in the example of the graph 113, the amount of change in the etching rate per movement amount of the wafer W is not constant.

[0047] FIG. 12 is a graph showing an example of the relationship between the movement amount of the wafer and the uniformity in the second embodiment. Graph 114 shown in FIG. 12 is a graph showing an example of the relationship when the correlation between the movement amount of the wafer W and the uniformity is complicated. Here, the uniformity represents the uniformity of the etching rate and corresponds to the amplitude of a sine approximation curve. Graph 114 is a graph in which the uniformity is plotted at movement amounts of 0.0 mm, 0.2 mm, 0.3 mm, 0.35 mm, and 0.4 mm, and the change in uniformity is nonlinear. In the case of the relationship shown in graph 113 or graph 114, the transfer position is intentionally shifted and teaching is performed twice to obtain the etching rate for each. Next, a linear equation representing the movement direction for two times is generated and the coordinates of the intersection of the linear equation are calculated, so that the movement direction and movement amount of the wafer W can be calculated.

[0048] 13 is a diagram showing an example of linear equations representing the movement direction in the second embodiment and the intersection coordinates of each linear equation. In FIG. 13, the center coordinates of the wafer W at the start of the evaluation are (x, y)=(0, 0), the center coordinates of the wafer W under the transfer position condition T1 are (x, y)=(-0.2, 0), and the center coordinates of the wafer W under the transfer position condition T2 are (x, y)=(0, -0.2). That is, under the condition T1, the transfer position of the wafer W is intentionally moved by -0.2 mm in the x-axis direction, and under the condition T2, the transfer position of the wafer W is intentionally moved by -0.2 mm in the y-axis direction.

[0049] 13, the control device 50 first calculates the movement direction from graphs 115 and 116 of sine approximation curves under transfer position conditions T1 and T2. Under condition T1, the control device 50 calculates based on graph 115 that the movement direction of the wafer W is the direction of sampling number "11." Under condition T2, the control device 50 calculates based on graph 116 that the movement direction of the wafer W is the direction of sampling number "38."

[0050] Next, the control device 50 draws a concentric circle 118 on the outer periphery of the wafer W at the transfer position under condition T1, based on a concentric circle 117 on the outer periphery of the wafer W at the start of the evaluation. Since the movement direction of the wafer W under condition T1 is the direction of the sampling number "11", the control device 50 draws a straight line 120 connecting a point on the concentric circle 118 corresponding to the sampling number "11" and a center 119 of the concentric circle 118. In other words, the linear equation representing the movement direction of the wafer W under condition T1 can be calculated as the linear equation representing the straight line 120.

[0051] Similarly, the control device 50 draws a concentric circle 121 of the outer periphery of the wafer W at the transfer position under condition T2, using the concentric circle 117 as a reference. Since the movement direction of the wafer W under condition T2 is the direction of the sampling number "38", the control device 50 draws a straight line 123 connecting the point on the concentric circle 121 corresponding to the sampling number "38" and the center 122 of the concentric circle 121. In other words, the linear equation representing the movement direction of the wafer W under condition T2 can be calculated as a linear equation representing the straight line 123. The linear equations representing the straight lines 120 and 123 may be expressed as vectors with each sampling number as the movement direction.

[0052] Next, the control device 50 calculates the coordinates of the intersection 124 between the straight lines 120 and 123. The intersection 124 becomes the coordinates of the center position of the wafer W after correction. In the example of Fig. 13, the coordinates of the intersection 124 are (x, y) = (-0.1018, 0). In this manner, by performing teaching twice with the transfer position intentionally shifted, the movement direction and movement amount of the wafer W can be calculated.

[0053] [Transport position adjustment method] Next, a method for adjusting the transfer position in the substrate processing apparatus 1 according to the second embodiment will be described below. Fig. 14 is a flow chart showing an example of the transfer position adjustment process in the second embodiment.

[0054] The controller 50 transports the wafer W accommodated in the FOUP of the load port 31 to the process module 20 via the loader module 30, the load lock module 40, and the transfer module 10, and places the wafer W at a first transfer position on the substrate support surface 211a of the main body 211. The controller 50 then etch the wafer W at the first transfer position (step S11), similar to step S1 in the first embodiment.

[0055] When the etching process is completed, the control device 50 causes the measurement unit 38 to measure and obtain the etching rate on a concentric circle of the outer periphery of the wafer W at the first transfer position (step S12), similar to step S2 in the first embodiment.

[0056] Next, the controller 50 transfers another wafer W accommodated in the FOUP of the load port 31 to the process module 20 via the loader module 30, the load lock module 40, and the transfer module 10, and places the wafer W at a second transfer position on the substrate support surface 211a of the main body 211. The controller 50 then etch the wafer W at the second transfer position (step S13), similar to step S1 in the first embodiment.

[0057] When the etching process is completed, the control device 50, in the same manner as in step S2 of the first embodiment, measures and obtains the etching rate on a concentric circle of the outer periphery of the wafer W at the second transfer position in the measuring unit 38 (step S14). Note that, if the silicon oxide film of the wafer W etched at the first transfer position has a sufficient thickness, the wafer W may be used for the etching process at the second transfer position, and the etching rate may be calculated from the difference in the etching amount.

[0058] The control device 50 generates a sine approximation curve in the circumferential direction of the concentric circle for each wafer W based on the etching rates of each wafer W at the first transfer position and the second transfer position (step S15). The control device 50 determines the moving direction of the wafer W based on the generated sine approximation curve, and calculates a linear equation representing the moving direction for each wafer W (step S16). The control device 50 calculates the intersection coordinates of each linear equation (step S17). That is, the control device 50 calculates the moving direction and the moving amount of the wafer W. The control device 50 adjusts the transfer position of the wafer W on the substrate support surface 211a when the transfer mechanism 11 transfers the wafer W to the process module 20 based on the calculated intersection coordinates (step S18). In this way, in the substrate processing apparatus 1 of the second embodiment, the substrate transfer position can be accurately and easily adjusted by intentionally shifting the transfer position and performing teaching twice. In addition, the maintenance time can be shortened. Furthermore, even during operation of the substrate processing apparatus 1, the substrate transfer position can be adjusted without opening the plasma processing chamber 60 to the atmosphere.

[0059] [Experimental Results] Next, the results of the teaching experiment in the second embodiment will be described with reference to Figs. 15 and 16. Figs. 15 and 16 are diagrams showing an example of the results of teaching in the second embodiment. In this experiment, teaching was performed under the conditions shown in the conditions T10 to T12 corresponding to the initial position, X-axis teaching, and Y-axis teaching in table 130 shown in Fig. 15, and condition T13 was obtained after correction, that is, as a result of teaching. Graph 131 in Fig. 15 graphs the uniformity at the initial position, X-axis teaching, Y-axis teaching, and after correction. Also, Fig. 16 shows raw data of the etching rate at the initial position, X-axis teaching, Y-axis teaching, and after correction, a fitted sine approximation curve, and a contour diagram, respectively.

[0060] As shown in Figures 15 and 16, in the initial position condition T10, the amount of movement is zero, that is, when the reference coordinates are (x, y) = (0, 0), the movement direction is the direction of sampling number "35". Also, the uniformity at the initial position was 0.64%. Note that the initial position was measured for comparison with the corrected position, and can be omitted in teaching.

[0061] In the X-axis teaching condition T11, when the movement amount, that is, the coordinates of the center position of the wafer W, was (x, y) = (0.2, 0), the movement direction was the direction of sampling number "32." Also, the uniformity in the X-axis teaching was 1.29%.

[0062] In the Y-axis teaching condition T12, when the movement amount, that is, the coordinates of the center position of the wafer W, was (x, y) = (0, 0.2), the movement direction was the direction of sampling number "28." In addition, the uniformity in the Y-axis teaching was 0.72%.

[0063] The coordinates of the intersection of the straight line equations corresponding to conditions T11 and T12 were calculated to be (x, y) = (-0.25, 0.07). When the transfer position was corrected (adjusted) so that the center position of the wafer W was at the coordinates of the intersection, that is, when the etching rate was measured under condition T13, the uniformity was 0.29%. Comparing the uniformity at the initial position and after the correction, it was confirmed that the uniformity had improved from 0.64% to 0.29%. Note that the measurement of the etching rate under condition T13 after the correction was performed for comparison with the initial position, and can be omitted in teaching.

[0064] The moving direction of the wafer W during the two teachings is not limited to the X-axis and Y-axis directions, and may be any angle as long as the linear equations intersect to obtain an intersection. The moving direction of the wafer W during the two teachings is preferably a direction that intersects at 90° to stabilize errors, but the moving directions of the wafer W may intersect at an angle of, for example, 45°. The intersection coordinates may be recalculated using the results after correction, that is, using three or more linear equations. In this case, the accuracy of the transfer position can be further improved.

[0065] As described above, according to the second embodiment, the substrate processing apparatus 1 is provided in a chamber (plasma processing chamber 60), and includes a mounting table (main body 211) having a first mounting surface (substrate support surface 211a) on which a substrate (wafer W) is mounted and a second mounting surface (ring support surface 211b) disposed on the outer periphery of the first mounting surface, a process module 20 including an edge ring (ring assembly 212) mounted on the second mounting surface, a measurement unit 38 for measuring an etching rate of the substrate, and a control unit (control device 50). The control unit is configured to control the substrate processing apparatus 1 to transport the substrate to different transport positions on the first mounting surface under specific processing conditions and etch the substrate for each transport position. The control unit is configured to control the substrate processing apparatus 1 to obtain, for each transport position, etching rates at multiple points on a concentric circle with respect to the substrate near the edge of the substrate from the measurement unit 38. The control unit is configured to control the substrate processing apparatus 1 to generate respective approximation curves in the circumferential direction of the concentric circle based on the respective etching rates obtained for each transport position. The control unit is configured to control the substrate processing apparatus 1 to calculate linear equations representing the substrate movement directions based on the generated approximation curves for each transport position. The control unit is configured to control the substrate processing apparatus 1 to calculate the intersection coordinates of each calculated linear equation. As a result, the substrate transport position can be adjusted accurately and easily.

[0066] Furthermore, according to the second embodiment, the approximation curve is generated after a smoothing process is performed on the acquired etching rate for each transfer position. As a result, it is possible to generate an approximation curve from which noise components have been removed.

[0067] According to each embodiment, the approximation curve is a sine approximation curve, so that the horizontal deviation of the wafer W with respect to the edge ring can be detected.

[0068] Moreover, according to each embodiment, the distance of the concentric circles from the edge of the substrate is within 30 mm, so that the deviation of the etching rate in the circumferential direction of the wafer W can be detected.

[0069] Furthermore, according to the second embodiment, the substrate processing apparatus 1 is controlled so as to adjust the transfer position of the substrate on the first placement surface based on the calculated intersection coordinates. As a result, teaching can be performed quantitatively.

[0070] According to the first embodiment, the substrate processing apparatus 1 includes a process module 20 provided inside a chamber, the process module 20 including a mounting table having a first mounting surface on which a substrate is mounted and a second mounting surface disposed on the outer periphery of the first mounting surface, an edge ring mounted on the second mounting surface, a measurement unit 38 for measuring an etching rate of the substrate, and a control unit. The control unit is configured to control the substrate processing apparatus 1 to etch the substrate under specific processing conditions. The control unit is configured to control the substrate processing apparatus 1 to obtain etching rates at a plurality of points on a concentric circle with the substrate near the edge of the substrate from the measurement unit 38. The control unit is configured to control the substrate processing apparatus 1 to generate an approximation curve in the circumferential direction of the concentric circle based on the obtained etching rate. The control unit is configured to control the substrate processing apparatus 1 to determine a movement direction of the substrate based on the generated approximation curve. The control unit is configured to control the substrate processing apparatus 1 to calculate a movement amount of the substrate in the determined movement direction based on the etching rate or the approximation curve. As a result, the substrate transport position can be accurately and easily adjusted.

[0071] Furthermore, according to the first embodiment, the approximation curve is generated after a smoothing process is performed on the acquired etching rate, which makes it possible to generate an approximation curve from which noise components have been removed.

[0072] According to the first embodiment, the movement amount is calculated by referring to a database that represents the relationship between the movement amount and the etching rate or the relationship between the movement amount and the amplitude of the approximation curve. As a result, the substrate transfer position can be adjusted by one teaching.

[0073] Furthermore, according to the first embodiment, the substrate processing apparatus 1 is controlled so as to adjust the transfer position of the substrate on the first placement surface based on the movement direction and movement amount. As a result, teaching can be performed quantitatively.

[0074] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims.

[0075] In addition, in each of the above-described embodiments, the measurement unit 38 is provided in the substrate processing apparatus 1, but the present invention is not limited to this. For example, the wafer W after the etching process may be transported to another measuring device, and the etching rate may be measured by the other measuring device.

[0076] In addition, in each of the above-described embodiments, the process module 20 is described as an example in which a process such as etching is performed on the wafer W using capacitively coupled plasma as a plasma source, but the disclosed technology is not limited to this. As long as the apparatus is one that performs a process on the wafer W using plasma, the plasma source is not limited to capacitively coupled plasma, and any plasma source such as inductively coupled plasma, microwave plasma, magnetron plasma, etc. can be used. [Explanation of symbols]

[0077] 1. Substrate Processing Equipment 10 Transfer Module 11. Transport mechanism 20 Process Module 21 Substrate support 30 Loader Module 38 Measuring part 40 Load Lock Module 50 Control device 60 Plasma Processing Chamber 70 Gas Supply Section 81 RF power supply 90 Exhaust System 211a Board support surface 211b Ring support surface 211 Main body 212 Ring Assembly W wafer

Claims

1. A substrate processing apparatus, comprising: The substrate processing apparatus includes: a process module provided inside the chamber, the process module including a mounting table having a first mounting surface for mounting a substrate thereon and a second mounting surface disposed on an outer periphery of the first mounting surface, and an edge ring mounted on the second mounting surface; A measurement unit for measuring an etching rate of the substrate; A control unit, the control unit is configured to control the substrate processing apparatus so as to transport the substrate to different transport positions on the first mounting surface under specific processing conditions and to etch the substrate for each of the transport positions; the control unit is configured to control the substrate processing apparatus to obtain, from the measurement unit, etching rates at a plurality of points on a concentric circle with the substrate in the vicinity of an edge of the substrate for each of the transport positions; the control unit is configured to control the substrate processing apparatus to generate approximate curves in a circumferential direction of each of the concentric circles based on the acquired etching rates for each of the transport positions; the control unit is configured to control the substrate processing apparatus to calculate a linear equation representing a moving direction of the substrate based on the generated approximation curve for each of the transport positions; The control unit is configured to control the substrate processing apparatus to calculate intersection coordinates of each of the calculated straight-line equations. Substrate processing equipment.

2. the approximation curve is generated after a smoothing process is performed on the acquired etching rate for each of the transport positions. The substrate processing apparatus according to claim 1 .

3. The approximation curve is a sine approximation curve. The substrate processing apparatus according to claim 1 .

4. The concentric circles are located at a distance of 30 mm or less from the edge of the substrate. The substrate processing apparatus according to any one of claims 1 to 3.

5. the control unit is configured to control the substrate processing apparatus to adjust a transport position of the substrate on the first placement surface based on the calculated intersection coordinates. The substrate processing apparatus according to any one of claims 1 to 4.

6. A method for adjusting a substrate transfer position in a substrate processing apparatus, comprising: The substrate processing apparatus includes: a process module provided inside the chamber, the process module including a mounting table having a first mounting surface for mounting a substrate thereon and a second mounting surface disposed on an outer periphery of the first mounting surface, and an edge ring mounted on the second mounting surface; A measurement unit for measuring an etching rate of the substrate; A control unit, transporting the substrate to different transport positions on the first mounting surface under specific processing conditions, and etching the substrate at each of the transport positions; acquiring, from the measurement unit, etching rates at a plurality of points on a concentric circle with respect to the substrate in the vicinity of an edge of the substrate for each of the transport positions; generating an approximation curve for each of the concentric circles in a circumferential direction based on the etching rate for each of the transfer positions obtained; calculating a linear equation representing a moving direction of the substrate based on the generated approximation curve for each of the transport positions; Calculating the coordinates of the intersections of the calculated straight line equations; The substrate transfer position adjustment method includes the steps of:

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