Substrate processing apparatus and substrate transfer position adjustment method

Abstract

The present disclosure relates to a substrate processing apparatus and a substrate conveying position adjustment method. The substrate processing apparatus includes a process module including a stage and an edge ring, the stage being disposed inside a chamber and having a first placement surface and a second placement surface, the edge ring being placed on the second placement surface; a measurement unit that measures an etching rate of a substrate; and a control unit that controls to convey the substrate to different conveying positions of the first placement surface under a specific processing condition and etch the substrate for each conveying position, acquires, for each conveying position, the etching rate at a plurality of points on a concentric circle of the substrate in the vicinity of an end portion of the substrate from the measurement unit, generates each approximate curve of a circumferential direction of the concentric circle based on each of the acquired etching rates of the conveying positions, calculates a linear expression indicating a moving direction of the substrate based on each of the approximate curves of the conveying positions, and calculates coordinates of an intersection point of each of the calculated linear expressions.

Description

Technical Field

[0001] This disclosure relates to a substrate processing apparatus and a method for adjusting the position of a substrate transport. Background Technology

[0002] In the case of etching processes in a substrate processing apparatus, the edge ring surrounding the substrate being processed is periodically replaced due to wear. It is well known that the placement of the replaced edge ring contains errors, resulting in misalignment between the edge ring and the substrate, which significantly negatively impacts the characteristics of the substrate's outer periphery. To address this, a method known as "teaching" is employed, where the control unit stores position coordinates while visually confirming the substrate's transport position to correct for errors in the relative position between the edge ring and the substrate.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-127069 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] This disclosure provides a substrate processing apparatus and a substrate transport position adjustment method that can accurately and easily adjust the substrate transport position.

[0008] Solution for solving the problem

[0009] A substrate processing apparatus according to one aspect of the present disclosure includes: a process module comprising a stage and an edge ring, the stage being disposed inside a chamber, the stage having a first mounting surface for mounting a substrate and a second mounting surface disposed on the outer periphery of the first mounting surface, the edge ring being mounted on the second mounting surface; a measurement unit for measuring the etching rate of the substrate; and a control unit 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 at each transport position; the control unit configured to: control the substrate processing apparatus to obtain etching rates at multiple locations on a concentric circle of the substrate near the end of the substrate from the measurement unit for each transport position; the control unit configured to: control the substrate processing apparatus to generate approximate curves in the circumferential direction of the concentric circle based on the etching rates of each transport position; the control unit configured to: control the substrate processing apparatus to calculate linear expressions representing the movement direction of the substrate based on the generated approximate curves of each transport position; and the control unit configured to: control the substrate processing apparatus to calculate the coordinates of the intersection points of the calculated linear expressions.

[0010] The effects of the invention

[0011] According to this disclosure, the substrate transport position can be adjusted accurately and easily. Attached Figure Description

[0012] Figure 1 This is a cross-sectional top view showing an example of the substrate processing apparatus in the first embodiment of the present disclosure.

[0013] Figure 2 This is a diagram illustrating an example of the plasma processing apparatus in the first embodiment.

[0014] Figure 3 This is a contour diagram illustrating an example of a wafer misalignment.

[0015] Figure 4 This is a graph representing an example of the generation of an approximate curve for the etching rate.

[0016] Figure 5 This is a diagram illustrating an example of using approximate curves for teaching.

[0017] Figure 6 This is a diagram illustrating an example of a worker demonstrating instruction.

[0018] Figure 7 This is a diagram representing an example of the parameters in the sine approximation method.

[0019] Figure 8 This is a graph illustrating an example of the relationship between the amount of wafer movement and the etching rate in the first embodiment.

[0020] Figure 9 This is a graph illustrating an example of the relationship between the amount of wafer movement and uniformity in the first embodiment.

[0021] Figure 10 This is a flowchart illustrating an example of the conveying position adjustment process in the first embodiment.

[0022] Figure 11 This is a graph illustrating an example of the relationship between the amount of wafer movement and the etching rate in the second embodiment.

[0023] Figure 12 This is a graph illustrating an example of the relationship between wafer movement and uniformity in the second embodiment.

[0024] Figure 13 This is a diagram showing an example of the coordinates of the intersection points of the linear formula representing the direction of movement and each linear formula in the second embodiment.

[0025] Figure 14 This is a flowchart illustrating an example of the conveying position adjustment process in the second embodiment.

[0026] Figure 15 This is a diagram illustrating an example of the teaching result in the second embodiment.

[0027] Figure 16 This is a diagram illustrating an example of the teaching result in the second embodiment. Detailed Implementation

[0028] The embodiments of the disclosed substrate processing apparatus and substrate transport position adjustment method will now be described in detail with reference to the accompanying drawings. Furthermore, the disclosed technology is not limited to the following embodiments.

[0029] In addition to visually adjusting the transport position, there are also methods for adjusting the transport position based on process characteristics such as etching rate, known as etching rate teaching. In conventional etching rate teaching, the operator manually adjusts the transport position according to process characteristics. However, these methods make it difficult to quantitatively calculate the appropriate adjustment amount. Therefore, there are cases of low adjustment accuracy and high adjustment time. Therefore, it is desirable to be able to accurately and easily adjust the substrate transport position. The teaching disclosed herein is related to etching rate teaching, but will be referred to hereafter simply as teaching.

[0030] (First Implementation)

[0031] [Structure of the substrate processing device]

[0032] Figure 1 This is a cross-sectional top view showing an example of the substrate processing apparatus in the first embodiment of the present disclosure. Figure 1 The substrate processing apparatus 1 shown is a substrate processing apparatus capable of performing various processes such as plasma processing on a single substrate (hereinafter also referred to as a wafer).

[0033] like Figure 1 As shown, the substrate processing apparatus 1 includes a transfer module 10, six process modules 20, a loading module 30, and two loading interlock modules 40.

[0034] The transfer module 10 has a roughly pentagonal shape when viewed from above. The transfer module 10 has a vacuum chamber, inside which a conveying mechanism 11 is arranged. The conveying mechanism 11 has a guide rail (not shown), two arms 12, and forks 13 positioned at the front ends of each arm 12 for supporting the wafer. Each arm 12 is a selectively compliant assembly robotic arm (SCARA) type, configured to rotate and extend freely. The conveying mechanism 11 moves along the guide rail to transport wafers between the process module 20 and the loading interlock module 40. Furthermore, the conveying mechanism 11 is not limited to simply transporting wafers between the process module 20 and the loading interlock module 40. Figure 1The structure shown. For example, each arm 12 of the conveying mechanism 11 may be configured to rotate and extend freely, and to lift freely.

[0035] Process module 20 is radially arranged around transfer module 10 and is connected to transfer module 10. Furthermore, process module 20 is an example of a plasma processing apparatus. Process module 20 has a processing chamber and a cylindrical substrate support 21 (stage) disposed inside. Substrate support 21 has multiple, for example, three thin rod-shaped lifting pins 22 that protrude freely from its upper surface. Each lifting pin 22 is arranged on the same circumference when viewed from above. Each lifting pin 22 supports and lifts the wafer placed on substrate support 21 by protruding from the upper surface of substrate support 21, and places the supported wafer on substrate support 21 by retracting into substrate support 21. After the wafer is placed on substrate support 21, the interior of process module 20 is depressurized and a processing gas is introduced. High-frequency electricity is applied to the interior of process module 20 to generate plasma, and plasma is used to perform plasma processing on the wafer. Transfer module 10 and process module 20 are separated by a freely opening and closing gate valve 23.

[0036] The loading module 30 is configured facing the transfer module 10. The loading module 30 is cuboid in shape and is an atmospheric transport chamber maintained at atmospheric pressure. Two loading interlock modules 40 are connected to one side of the loading module 30 along its long side. Three loading ports 31 are connected to the other side of the loading module 30 along its long side. FOUPs (Front-Opening Unified Pods) (not shown) are mounted in the loading ports 31; these FOUPs are containers for holding multiple wafers. An alignment device 32 is connected to one side of the loading module 30 along its short side. Additionally, a transport mechanism 35 is configured within the loading module 30. A measuring unit 38 is connected to the other side of the loading module 30 along its short side.

[0037] Aligner 32 is used for wafer alignment. Aligner 32 has a rotary table 33 that rotates via a drive motor (not shown). Rotary table 33 has, for example, a diameter smaller than the wafer diameter, and is configured to rotate with the wafer mounted on its upper surface. An optical sensor 34 for detecting the outer periphery of the wafer is provided near the rotary table 33. In alignmenter 32, the center position of the wafer and the direction of the cut relative to the center of the wafer are detected by the optical sensor 34, and alignmenter 32 transfers the wafer to fork 37 (described later) in a predetermined position and orientation of the wafer center position and the cut orientation. Thus, the wafer transport position is adjusted in a predetermined position and orientation within loading interlock module 40.

[0038] The conveying mechanism 35 includes a guide rail (not shown), an arm 36, and a fork 37. The arm 36 is a selective compliant assembly robotic arm type, configured to move freely along the guide rail and to rotate, extend, and lift freely. The fork 37 is located at the front end of the arm 36 and is used to support the wafer. In the loading module 30, the conveying mechanism 35 conveys wafers between the FOUP, the alignment device 32, the measuring unit 38, and the loading interlock module 40, which are located at each loading port 31. Furthermore, the conveying mechanism 35 is not limited to conveying wafers between the FOUP, the alignment device 32, the measuring unit 38, and the loading interlock module 40. Figure 1 The structure shown.

[0039] The measurement unit 38 measures the amount of etching on the wafer after the etching process has been completed in the process module 20. The measurement unit 38 calculates the etching rate based on the measured amount of etching and the etching process time. In other words, the measurement unit 38 measures the etching rate. The measurement unit 38 outputs the measured etching rate to the control device 50, which will be described later. Furthermore, the measurement unit 38 is not limited to being located adjacent to the loading module 30; it may also be located inside the loading module 30.

[0040] A loading interlock module 40 is configured between the transfer module 10 and the loading module 30. The loading interlock module 40 has a variable internal pressure chamber capable of switching its internal pressure between vacuum and atmospheric pressure. The loading interlock module 40 also has a cylindrical platform 41 configured inside. When transferring a wafer from the loading module 30 to the transfer module 10, the loading interlock module 40 receives the wafer from the loading module 30 while maintaining its internal pressure at atmospheric pressure, then depressurizes the internal pressure before transferring the wafer to the transfer module 10. Conversely, when transferring a wafer from the transfer module 10 to the loading module 30, the loading interlock module 40 receives the wafer from the transfer module 10 while maintaining its internal pressure at vacuum, then pressurizes the internal pressure to atmospheric pressure before transferring the wafer to the loading module 30. The platform 41 has multiple, for example, three thin rod-shaped lifting pins 42 that protrude freely from its upper surface. Each lifting pin 42, when viewed from above, is arranged on the same circumference. It supports and lifts the wafer by protruding from the upper surface of the stage 41, and places the supported wafer onto the stage 41 by retracting into it. The loading interlock module 40 and the transfer module 10 are separated by a freely opening and closing gate valve (not shown). Additionally, the loading interlock module 40 and the loading module 30 are separated by a freely opening and closing gate valve (not shown).

[0041] 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), RAM (Random Access Memory), ROM (Read Only Memory), auxiliary storage devices, etc. The CPU operates based on the program stored in the ROM or auxiliary storage devices to control the operation of various structural elements of the substrate processing apparatus 1.

[0042] [Structure of Process Module 20]

[0043] Next, a structural example of a capacitively coupled plasma processing apparatus, which is one example of process module 20, will be described. Furthermore, in the following description, process module 20 will also be referred to as capacitively coupled plasma processing apparatus 20 or simply as plasma processing apparatus 20. Figure 2 This is a diagram illustrating an example of the plasma processing apparatus in the first embodiment.

[0044] The capacitively coupled plasma processing apparatus 20 includes a plasma processing chamber 60, a gas supply unit 70, a power supply 80, and an exhaust system 90. Additionally, the plasma processing apparatus 20 includes a substrate support 21 and a gas inlet. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 60. The gas inlet includes a spray head 61. The substrate support 21 is disposed within the plasma processing chamber 60. The spray head 61 is disposed above the substrate support 21. In one embodiment, the spray head 61 constitutes at least a portion of the ceiling of the plasma processing chamber 60. The plasma processing chamber 60 has a plasma processing space 60s defined by the spray head 61, the sidewall 60a of the plasma processing chamber 60, and the substrate support 21. The sidewall 60a is grounded. The spray head 61 and the substrate support 21 are electrically insulated from the housing of the plasma processing chamber 60.

[0045] The substrate support portion 21 includes a main body portion 211 and a ring assembly 212. The main body portion 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. When viewed from above, the annular region 211b of the main body portion 211 surrounds the central region 211a of the main body portion 211. The wafer W is disposed on the central region 211a of the main body portion 211, and the ring assembly 212 is disposed on the annular region 211b of the main body portion 211 in such a way that it surrounds the wafer W on the central region 211a of the main body portion 211. In one embodiment, the main body portion 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 the 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. Additionally, although not shown in the figure, the substrate support 21 may also include a temperature control 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 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. Furthermore, the substrate support 21 may also include a heat transfer gas supply section configured to supply heat transfer gas between the back surface of the wafer W and the substrate support surface 211a.

[0046] The spray head 61 is configured to introduce at least one process gas from the gas supply unit 70 into the plasma processing space 60s. The spray head 61 has at least one gas supply port 61a, at least one gas diffusion chamber 61b, and a plurality of gas inlets 61c. The process gas supplied to the gas supply port 61a is introduced into the plasma processing space 60s through the gas diffusion chamber 61b and then through the plurality of gas inlets 61c. Additionally, the spray head 61 includes a conductive member. The conductive member of the spray head 61 functions as an upper electrode. Furthermore, the gas inlet unit may, in addition to including the spray head 61, include one or more side gas injectors (SGIs) mounted on one or more openings formed in the sidewall 60a.

[0047] The gas supply unit 70 may include at least one gas source 71 and at least one flow controller 72. In one embodiment, the gas supply unit 70 is configured to supply at least one type of process gas from its respective gas source 71 to the spray head 61 via its respective flow controller 72. Each flow controller 72 may, for example, include a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 70 may also include at least one flow modulation device for modulating or pulsed the flow rate of the at least one type of process gas.

[0048] The power supply 80 includes an RF power supply 81 coupled to the plasma processing chamber 60 via at least one impedance matching circuit. The RF power supply 81 is configured to supply at least one RF signal (RF power), such as an RF source signal and an RF bias signal, to the conductive members of the substrate support 21 and / or the conductive members of the spray head 61. As a result, plasma is formed from at least one processing gas supplied to the plasma processing space 60s. Therefore, the RF power supply 81 can function as at least part of the plasma generation unit. Furthermore, by supplying an RF bias signal to the conductive members of the substrate support 21, a bias potential can be generated on the wafer W, thereby attracting the ionic components in the formed plasma to the wafer W.

[0049] In one embodiment, the RF power supply 81 includes a first RF generation unit 81a and a second RF generation unit 81b. The first RF generation unit 81a is configured to generate an RF source signal (source RF power) for plasma generation by coupling to a conductive member of the substrate support 21 and / or a conductive member of the spray head 61 via at least one impedance matching circuit. In one embodiment, the RF source signal has a frequency in the range of 13MHz to 150MHz. In one embodiment, the first RF generation unit 81a may also be configured to generate multiple RF source signals with different frequencies. The generated one or more RF source signals are provided to the conductive member of the substrate support 21 and / or the conductive member of the spray head 61. The second RF generation unit 81b is configured to generate an RF bias signal (bias RF power) by coupling to a conductive member of the substrate support 21 via at least one impedance matching circuit. In one embodiment, the RF bias signal has a frequency lower than the frequency of the RF source signal. In one embodiment, the RF bias signal has a frequency in the range of 400kHz to 13.56MHz. In one embodiment, the second RF generation unit 81b may also be configured to generate multiple RF bias signals with different frequencies. The generated one or more RF bias signals are provided to the conductive members of the substrate support unit 21. Additionally, in various embodiments, at least one of the RF source signal and the RF bias signal may be pulsed.

[0050] Alternatively, 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 generating unit 82a and a second DC generating unit 82b. In one embodiment, the first DC generating unit 82a is configured to generate a first DC signal by connecting to a conductive member of the substrate support 21. The generated first DC signal is applied to the conductive member of the substrate support 21. In one embodiment, the first DC signal may also be applied to other electrodes, such as electrodes within an electrostatic chuck. In one embodiment, the second DC generating unit 82b is configured to generate a second DC signal by connecting to a conductive member of the spray head 61. The generated second DC signal is applied to the conductive member of the spray head 61. In various embodiments, the first DC signal and the second DC signal may also be pulsed. Furthermore, the first DC generating unit 82a and the second DC generating unit 82b may be provided in addition to the RF power supply 81, or the first DC generating unit 82a may replace the second RF generating unit 81b.

[0051] The exhaust system 90 can be connected to a gas outlet 60e, for example, located 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 within 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.

[0052] [Calculation of direction of movement]

[0053] Next, use Figures 3 to 7 This will explain the calculation of the moving direction of wafer W. Figure 3 This is a contour diagram illustrating an example of wafer misalignment. Figure 3 The outline diagram shown illustrates the sampling numbers "1" to "40" and the etching rate of the oxide film (Ox) set on the circumference of the outer periphery of wafer W. The sampling numbers are evenly spaced on the circumference of concentric circles with a radius of 147 mm on wafer W. Figure 3 As shown in the example, the etching rate near sample number "36" is slow, while the etching rate near sample number "18" is fast. The relationship between the etching rate and the position of wafer W is that the faster the etching rate, the farther the wafer W is from the edge ring. Furthermore, it is preferable to set the distance between the concentric circles of the sample numbers and the end of wafer W to be within 30 mm.

[0054] Figure 4 This is a graph illustrating an example of how an approximate curve of the etching rate is generated. (Example:) Figure 4 As shown, curve 101 is a representation of... Figure 3The graphs are obtained by plotting the raw data of the etching rates for sampling numbers "1" to "40" as specified in the diagram. Graph 101 includes noise caused by factors other than the horizontal position of the wafer W, such as vertical position and particles. Graph 102 is obtained by smoothing graph 101 using a 3-point moving average. Graph 103 is obtained by fitting a sinusoidal approximation to graph 102 to generate an approximate curve. In graph 103, the direction corresponding to the sampling number with the highest etching rate is the direction in which the edge ring is furthest from the wafer W. That is, the direction with the highest etching rate is the direction in which the wafer W should be moved.

[0055] Figure 5 This diagram illustrates an example of teaching using an approximate curve. In Figure 4 In curve 103, the direction with the highest etching rate is the direction of sampling number "12". Therefore, through one teaching demonstration, such as Figure 5 As shown in vector 104, the direction of movement of wafer W corresponds to the direction of sampling number "12". Furthermore, the amount of movement cannot be clearly determined from graph 103.

[0056] Figure 6 This diagram illustrates an example of a situation where an operator is demonstrating. On the other hand, in situations where an operator is demonstrating, in... Figure 4 In curve 101, the etching rate of sample number "18" is the highest, therefore the wafer W is moved to the following position for the first time. Figure 6 As shown in vector 105, the wafer was moved 0.2 mm towards sample number "18". Then, etching was performed, and the etching rates for samples "1" to "40" were measured. When plotted similarly to curve 101, the etching rate for sample number "3" was the highest. The operator then adjusted the wafer W's transport position a second time, moving it 0.1 mm towards sample number "3" as shown in vector 106. After this adjustment, etching was performed again. The operator then adjusted the wafer W a third time, as shown in vector 107, towards sample number "11", and a fourth time, as shown in vector 108, towards sample number "11". The result of these four teaching operations was that wafer W moved 0.237 mm towards sample number "13" as shown in vector 109, which is the result of combining vectors 105 to 108. Thus, by using a sinusoidal approximation... Figure 5 Vector 104 can determine the direction of sample number "12" with a single teaching, but when the operator performs the operation, four teachings are required to obtain vector 109. That is, when using the sine approximation, the direction of movement can be calculated with a single teaching without unnecessary actions caused by noise from the etching rate.

[0057] Next, the details of generating the approximate curve using the sine approximation will be explained. In the sine approximation, the following equation (1) is used.

[0058] y=asinb(x+c)+d…(1)

[0059] Here, parameter a represents the amplitude of the sine wave, i.e., the deviation in the etching rate. Parameter a almost corresponds to the amount of movement of wafer W. Parameter b represents the period of the sine wave. Since only the planar deviation between the edge ring and wafer W needs to be considered, that is, only one circumference sample is required, parameter b is fixed at "1". Parameter c represents the phase of the sine wave, indicating the direction of deviation of wafer W. Parameter c almost corresponds to the direction of movement of wafer W. Parameter d represents the offset, and parameter d is fixed at the average etching rate of sampling numbers "1" to "40". Furthermore, by fixing the parameters b and d, the solution to the consecutive equations is prevented from diverging or falling into a local optimum.

[0060] Figure 7 This is a diagram representing an example of the parameters in the sine approximation method. Figure 7 Table 110 shows a portion of the parameters used in a table calculation software to perform a sine approximation by using a solver that calculates the optimal value while changing the values ​​of multiple variables. The “Sampling No.” column indicates the sampling number mentioned above, and the value is expressed in radians when substituted into x. The “ER” column indicates the measured value of the etching rate (in “nm”) at the corresponding sampling number. The “Approximation” column corresponds to Equation (1) and shows the approximate value y of the etching rate corresponding to the sampling number and when any values ​​are substituted into parameters a and c. The “Square of Error” column indicates the square of the error between the approximate value and the measured value. In the solver, parameters a and c are calculated for the 40 rows of Table 110 corresponding to sampling numbers “1” to “40” to minimize the sum of the squares of the error represented by “Sum (Square of Error)”. In addition, it is only necessary to calculate the solution of the consecutive equations of Equation (1) corresponding to sampling numbers “1” to “40”, that is, it is only necessary to change parameters a and c to perform a sine approximation, or other algorithms can be used.

[0061] [Calculation of Movement Amount 1]

[0062] Figure 8 This is a graph illustrating an example of the relationship between the amount of wafer movement and the etching rate in the first embodiment. Figure 8The graph 111 shown is an example of the simple correlation between the amount of wafer W movement and the etching rate. Graph 111 illustrates the change in etching rate when the wafer W movement is set to 0.05 mm for each teaching iteration, and this is repeated four times. In the first teaching iteration, the etching rate changes by -0.2 nm / min when wafer W is moved 0.05 mm from its initial position. In the second teaching iteration, the etching rate changes by -0.2 nm / min when wafer W is moved 0.05 mm from its initial position. Similarly, in the third and fourth teaching iterations, the etching rate changes by -0.2 nm / min each time wafer W is moved 0.05 mm from its previous position. In other words, in the example of graph 111, the change in etching rate for each movement of wafer W is constant.

[0063] Figure 9 This is a graph illustrating an example of the relationship between the amount of wafer movement and uniformity in the first embodiment. Figure 9 The curve 112 shown is an example of the simple correlation between the movement amount of wafer W and uniformity. Here, uniformity represents the uniformity of the etching rate, equivalent to the amplitude of a sinusoidal approximation curve. In curve 112, the uniformity curve is obtained by plotting the movement amount in 0.1 mm increments from 0 mm to 0.4 mm, and the change in uniformity is linear. Having confirmed the relationship shown in curve 111 or curve 112, a database showing the relationship between movement amount and etching rate, or the relationship between movement amount and the amplitude (uniformity) of the approximation curve, can be pre-created. By performing only one teaching operation to obtain the etching rate, the movement amount of wafer W can be calculated by referring to the pre-created database based on the change in etching rate or uniformity.

[0064] [Method for adjusting the delivery location]

[0065] Next, the method for adjusting the transport position in the substrate processing apparatus 1 of the first embodiment will be described. Figure 10 This is a flowchart illustrating an example of the transport position adjustment process in the first embodiment. Furthermore, in the following description, the operation of each structural element of the substrate processing apparatus 1 is controlled by the control device 50.

[0066] The control device 50 transports the FOUP wafer W housed in the loading port 31 to the process module 20 via the loading module 30, the loading interlock module 40, and the transfer module 10, and places it on the substrate support surface 211a of the main body 211. In addition, a silicon oxide film (SiO2) is formed on the wafer W, for example, to measure the etching rate.

[0067] Subsequently, the control device 50 closes the opening and exhausts gas from the plasma processing space 60s by controlling the exhaust system 90 to achieve a predetermined vacuum level. Additionally, the control device 50 regulates the temperature of the wafer W to a predetermined temperature by controlling a temperature regulation module (not shown). The control device 50 then starts supplying process gas to fill the plasma processing space 60s. The process gas may be, for example, a fluorine-containing gas. The control device 50 uses the plasma generated from the process gas supplied by the RF power supply 81 with an RF source signal and an RF bias signal to perform etching on the wafer W (step S1).

[0068] When the etching process is complete, the control device 50 stops the supply of process gas, the RF source signal, and the RF bias signal, and opens the opening (not shown). The control device 50 causes the wafer W to be moved from the process module 20 and transported to the measurement unit 38 via the transfer module 10, the loading interlock module 40, and the loading module 30.

[0069] The control device 50 measures and acquires the etching rate on the concentric circles of the outer periphery of the wafer W in the measurement unit 38 (step S2). Based on the acquired etching rate, the control device 50 generates a sinusoidal approximation curve of the circumferential direction of the concentric circles (step S3). Based on the generated sinusoidal approximation curve, the control device 50 determines the movement direction of the wafer W (step S4).

[0070] The control device 50 refers to a database showing the relationship between the amount of movement and the etching rate, or the relationship between the amount of movement and uniformity (amplitude of a sinusoidal approximation curve), to calculate the amount of movement of the wafer W in the determined movement direction (step S5). Based on the determined movement direction and the calculated amount of movement, the control device 50 adjusts the transport position of the wafer W on the substrate support surface 211a when the transport mechanism 11 transports 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 amount of movement of the wafer W are determined based on the etching rate, so the substrate transport position can be adjusted accurately and easily. In addition, maintenance time can be shortened. Furthermore, even during the operation of the substrate processing apparatus 1, the substrate transport position can be adjusted without opening the plasma processing chamber 60 to the atmosphere.

[0071] (Second Implementation)

[0072] In the first embodiment described above, when the correlation between the amount of movement and the etching rate is simple, the amount of movement of the wafer W is calculated by referring to a pre-made database. However, when the correlation between the amount of movement and the etching rate is complex, it is difficult to database the data. In this case, it can be set up so that the etching rate is obtained twice by intentionally shifting the transport position, thereby calculating the movement direction and amount of movement of the wafer W. This implementation will be described as the second embodiment. Furthermore, the structure of the substrate processing apparatus in the second embodiment is the same as that in the first embodiment, so descriptions of its repetitive structures and operations are omitted.

[0073] [Calculation of Movement Amount 2]

[0074] Figure 11 This is a graph illustrating an example of the relationship between the amount of wafer movement and the etching rate in the second embodiment. Figure 11 The graph 113 shown is an example of a complex relationship between the amount of wafer W moved and the etch rate. Graph 113 illustrates the change in etch rate when the wafer W is moved by 0.05 mm in each teaching iteration, with four teaching iterations. In the first teaching iteration, when wafer W is moved 0.05 mm from its initial position, the change in etch rate is almost constant, at 0.0 nm / min. In the second teaching iteration, when wafer W is moved 0.05 mm from its initial position, the etch rate changes by -0.37 nm / min. In the third teaching iteration, when wafer W is moved 0.05 mm from its second teaching position, the etch rate changes by -0.14 nm / min. In the fourth teaching iteration, when wafer W is moved 0.05 mm from its third teaching position, the etch rate changes by -0.51 nm / min. In other words, in the example of graph 113, the change in etch rate per unit movement of wafer W is not constant.

[0075] Figure 12 This is a graph illustrating an example of the relationship between wafer movement and uniformity in the second embodiment. Figure 12The curve 114 shown is an example of the complex relationship between the amount of wafer W's movement and uniformity. Here, uniformity represents the uniformity of the etching rate, equivalent to the amplitude of a sinusoidal approximation curve. Curve 114 is a graph of uniformity obtained by plotting movement amounts of 0.0 mm, 0.2 mm, 0.3 mm, 0.35 mm, and 0.4 mm; the variation in uniformity is non-linear. In the case of a relationship as shown in curve 113 or curve 114, the transport position is intentionally offset to perform two teaching operations, and the etching rate is obtained separately. Then, the linear expression representing the movement direction is generated twice, and the coordinates of the intersection points of the linear expressions are calculated, thereby enabling the calculation of the movement direction and amount of wafer W.

[0076] Figure 13 This is a diagram illustrating an example of the linear formulas representing the direction of movement in the second embodiment, as well as the coordinates of the intersection points of these linear formulas. Figure 13 In the evaluation, the center coordinates of wafer W at the start of the evaluation are set to (x, y) = (0, 0). Under condition T1, the center coordinates of wafer W are set to (x, y) = (-0.2, 0). Under condition T2, the center coordinates of wafer W are set to (x, y) = (0, -0.2). That is, under condition T1, the transport position of wafer W is intentionally moved -0.2 mm along the x-axis, and under condition T2, the transport position of wafer W is intentionally moved -0.2 mm along the y-axis.

[0077] like Figure 13 As shown, the control device 50 first calculates the movement direction based on curves 115 and 116 of the sinusoidal approximation curves under conditions T1 and T2 of the conveying position. Under condition T1, the control device 50 calculates based on curve 115 that the movement direction of the wafer W is the direction of sampling number "11". Furthermore, under condition T2, the control device 50 calculates based on curve 116 that the movement direction of the wafer W is the direction of sampling number "38".

[0078] Next, the control device 50 draws a concentric circle 118 around the outer periphery of the wafer W at the transport position of condition T1, using the concentric circle 117 of the outer periphery of the wafer W at the start of the evaluation as a reference. Since the direction of movement of the wafer W in condition T1 is the direction of sampling number "11", the control device 50 draws a straight line 120 connecting the point on the concentric circle 118 corresponding to the sampling number "11" to the center 119 of the concentric circle 118. That is, the linear expression representing the direction of movement of the wafer W under condition T1 can be calculated as the linear expression representing the straight line 120.

[0079] Similarly, the control device 50 draws a concentric circle 121 around the outer periphery of the wafer W at the transport position under condition T2, using the concentric circle 117 as a reference. Since the direction of movement of the wafer W under condition T2 is the direction of sampling number "38", the control device 50 draws a straight line 123 connecting the point on the concentric circle 121 corresponding to the same sampling number "38" to the center 122 of the concentric circle 121. That is, the linear expression representing the direction of movement of the wafer W under condition T2 can be calculated as the linear expression representing the straight line 123. Alternatively, the linear expressions representing the straight lines 120 and 123 can be expressed by using each sampling number as a vector representing the direction of movement.

[0080] Next, the control device 50 calculates the coordinates of the intersection point 124 of lines 120 and 123. Intersection point 124 represents the coordinates of the center position of the corrected wafer W. Figure 13 In the example, the coordinates of intersection point 124 are (x, y) = (-0.1018, 0). Thus, by performing the teaching twice to intentionally offset the transport position, the direction and amount of movement of wafer W can be calculated.

[0081] [Method for adjusting the delivery location]

[0082] Next, the method for adjusting the transport position in the substrate processing apparatus 1 of the second embodiment will be described. Figure 14 This is a flowchart illustrating an example of the conveying position adjustment process in the second embodiment.

[0083] The control device 50 transports the wafer W housed in the FOUP at the loading port 31 to the process module 20 via the loading module 30, the loading interlock module 40, and the transfer module 10, and places it at the first transport position on the substrate support surface 211a of the main body 211. Then, similar to step S1 in the first embodiment, the control device 50 causes the wafer W to undergo etching at the first transport position (step S11).

[0084] When the etching process is completed, similar to step S2 in the first embodiment, the control device 50 causes the measuring unit 38 to measure and acquire the etching rate on the concentric circle of the outer periphery of the wafer W at the first transport position (step S12).

[0085] Next, the control device 50 transports the other wafers W housed in the FOUP at the loading port 31 to the process module 20 via the loading module 30, the loading interlock module 40, and the transfer module 10, and places them at the second transport position on the substrate support surface 211a of the main body 211. Then, similar to step S1 in the first embodiment, the control device 50 causes the wafers W to undergo etching at the second transport position (step S13).

[0086] When the etching process is completed, similar to step S2 in the first embodiment, the control device 50 causes the measuring unit 38 to measure and acquire the etching rate on the concentric circle of the outer periphery of the wafer W at the second transport position (step S14). Alternatively, if the silicon oxide film of the wafer W etched at the first transport position has sufficient thickness, the wafer W can be used to perform the etching process at the second transport position, and the etching rate can be calculated based on the difference in etching amount.

[0087] Based on the etch rate of each wafer W at the first and second transport positions, the control device 50 generates a circumferential sinusoidal approximation curve of concentric circles for each wafer W (step S15). The control device 50 determines the movement direction of the wafer W based on the generated sinusoidal approximation curve and calculates a linear expression representing the movement direction for each wafer W (step S16). The control device 50 calculates the intersection coordinates of each linear expression (step S17). That is, the control device 50 calculates the movement direction and amount of movement of the wafer W. Based on the calculated intersection coordinates, the control device 50 adjusts the transport position of the wafer W on the substrate support surface 211a when the transport mechanism 11 transports the wafer W to the process module 20 (step S18). In this way, in the substrate processing apparatus 1 of the second embodiment, by intentionally offsetting the transport position for two teaching operations, the substrate transport position can be adjusted accurately and easily. Furthermore, maintenance time can be shortened. Furthermore, even when using the substrate processing apparatus 1, the substrate transport position can be adjusted without opening the plasma processing chamber 60 to the atmosphere.

[0088] [Experimental Results]

[0089] Next, use Figure 15 and Figure 16 To illustrate the experimental results of the teaching in the second embodiment. Figure 15 and Figure 16 This diagram illustrates an example of the teaching result in the second embodiment. In this experiment, in conjunction with... Figure 15 The initial position, X-axis teaching, and Y-axis teaching conditions T10 to T12 shown in Table 130 are used for teaching. After correction, condition T13 is obtained as the result of the teaching. Figure 15 In graph 131, the initial position, X-axis teaching, Y-axis teaching, and corrected uniformity curves are plotted. Additionally, in... Figure 16 The diagram shows the raw data for the initial position, X-axis teaching, Y-axis teaching, and corrected etching rate, as well as the sinusoidal approximation curve and contour plot obtained by fitting.

[0090] like Figure 15 and Figure 16As shown, in condition T10 of the initial position, when the movement is zero, that is, when the coordinates set as the reference (x, y) = (0, 0), the direction of movement is the direction of sampling number "35". Furthermore, the uniformity at the initial position is 0.64%. Also, the initial position is measured for comparison with the calibrated position and can be omitted during teaching.

[0091] In X-axis teaching condition T11, when the coordinates of the movement amount, i.e., the center position of wafer W, are set to (x, y) = (0.2, 0), the movement direction is the direction of sampling number "32". Additionally, the uniformity in X-axis teaching is 1.29%.

[0092] In the Y-axis teaching condition T12, when the coordinates of the movement amount, i.e., the center position of wafer W, are set to (x, y) = (0, 0.2), the movement direction is the direction of sampling number "28". Additionally, the uniformity in the Y-axis teaching is 0.72%.

[0093] When calculating the intersection coordinates of the linear equations corresponding to conditions T11 and T12, the coordinates are (x, y) = (-0.25, 0.07). With the transport position corrected (adjusted) so that the center position of wafer W is this intersection coordinate, that is, when the etching rate is measured under condition T13, the uniformity is 0.29%. When comparing the initial position with the corrected uniformity, it can be confirmed that the uniformity has improved from 0.64% to 0.29%. Furthermore, the measurement of the etching rate under the corrected condition T13 is for comparison with the initial position and can be omitted in the teaching process.

[0094] Furthermore, the movement direction of wafer W during the two teaching operations is not limited to the X-axis or Y-axis directions; as long as the linear equations intersect and the intersection point can be determined, the angle can be arbitrary. Preferably, the movement directions of wafer W during the two teaching operations intersect at 90° to stabilize the error; alternatively, the movement directions of wafer W can intersect at an angle such as 45°. Alternatively, the corrected results can be used, that is, the intersection point coordinates can be recalculated using three or more linear equations. In this case, the accuracy of the transport position can be further improved.

[0095] According to the second embodiment, the substrate processing apparatus 1 includes: a process module 20 comprising a stage (main body 211) and an edge ring (ring assembly 212), the stage (main body 211) being disposed inside a chamber (plasma processing chamber 60), the stage (main body 211) having a first mounting surface (substrate support surface 211a) for mounting a substrate (wafer W) and a second mounting surface (ring support surface 211b) disposed on the outer periphery of the first mounting surface, the edge ring being mounted on the second mounting surface; a measurement unit 38 for measuring the 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 to etch the substrate at each transport position. The control unit is also configured to control the substrate processing apparatus to obtain, from the measurement unit 38, the etching rate at multiple locations near the end of the substrate on a concentric circle of the substrate for each transport position. The control unit is configured to: control the substrate processing apparatus 1 to generate approximate curves along the circumference of concentric circles based on the etching rate of each acquired transport position; control the substrate processing apparatus 1 to calculate linear equations representing the movement direction of the substrate based on the generated approximate curves for each transport position; and control the substrate processing apparatus 1 to calculate the coordinates of the intersection points of the calculated linear equations. As a result, the substrate transport position can be adjusted accurately and easily.

[0096] Furthermore, according to the second embodiment, the approximate curve is generated after smoothing the etching rate at each transport position. As a result, an approximate curve with noise components removed can be generated.

[0097] Furthermore, according to various embodiments, the approximation curve is a sinusoidal approximation curve. As a result, it is possible to detect the deviation of the wafer W relative to the edge ring in the horizontal direction.

[0098] Furthermore, according to each embodiment, the distance between the concentric circles and the end of the substrate is within 30 mm. As a result, deviations in the circumferential etching rate of the wafer W can be detected.

[0099] Furthermore, according to the second embodiment, the control substrate processing apparatus 1 is configured to adjust the transport position of the substrate on the first mounting surface based on the calculated intersection coordinates. As a result, quantitative teaching can be performed.

[0100] Furthermore, according to the first embodiment, the substrate processing apparatus 1 includes: a process module 20 comprising a mounting stage and an edge ring, the mounting stage being disposed inside a chamber, the mounting stage having a first mounting surface for mounting a substrate and a second mounting surface disposed on the outer periphery of the first mounting surface, the edge ring being mounted on the second mounting surface; a measuring unit 38 for measuring the 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; control the substrate processing apparatus 1 to obtain etching rates at multiple locations on a concentric circle of the substrate near the end of the substrate from the measuring unit 38; control the substrate processing apparatus 1 to generate an approximate circumferential curve of the concentric circle based on the obtained etching rate; control the substrate processing apparatus 1 to determine the moving direction of the substrate based on the generated approximate curve; and control the substrate processing apparatus 1 to calculate the amount of substrate movement in the moving direction determined based on the etching rate or the approximate curve. As a result, the substrate transport position can be adjusted accurately and easily.

[0101] Furthermore, according to the first embodiment, the approximate curve is generated after smoothing the obtained etching rate. As a result, an approximate curve with noise components removed can be generated.

[0102] Furthermore, according to the first embodiment, the movement amount is calculated with reference to a database representing the relationship between movement amount and etching rate, or the relationship between movement amount and the amplitude of an approximate curve. As a result, the substrate transport position can be adjusted in a single teaching operation.

[0103] Furthermore, according to the first embodiment, the control substrate processing apparatus 1 is configured to adjust the transport position of the substrate on the first mounting surface based on the moving direction and the amount of movement. As a result, quantitative teaching can be performed.

[0104] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. Various omissions, substitutions, and modifications may be made to the above embodiments without departing from the appended claims and their spirit.

[0105] Furthermore, in the embodiments described above, the measurement unit 38 is provided in the substrate processing apparatus 1, but this is not a limitation. For example, it may be configured to transport the etched wafer W to another measurement apparatus to measure the etching rate in that other measurement apparatus.

[0106] Furthermore, in the embodiments described above, a process module 20 that uses capacitively coupled plasma as a plasma source to perform etching and other processes on wafer W has been used as an example, but the disclosed technology is not limited to this. Any apparatus that uses plasma to process wafer W is acceptable, and the plasma source is not limited to capacitively coupled plasma; for example, any plasma source such as inductively coupled plasma, microwave plasma, or magnetron plasma can be used.

[0107] Explanation of reference numerals in the attached figures

[0108] 1: Substrate processing apparatus; 10: Transfer module; 11: Conveying mechanism; 20: Process module; 21: Substrate support; 30: Loading module; 38: Measurement unit; 40: Loading interlock module; 50: Control device; 60: Plasma processing chamber; 70: Gas supply unit; 81: RF power supply; 90: Exhaust system; 211a: Substrate support surface; 211b: Ring support surface; 211: Main body; 212: Ring assembly; W: Wafer.

Claims

1. A substrate processing apparatus comprising: A process module includes a stage and an edge ring. The stage is disposed inside a chamber and has a first mounting surface for mounting a substrate and a second mounting surface disposed on the outer periphery of the first mounting surface. The edge ring is mounted on the second mounting surface. The measuring unit measures the etching rate of the substrate; and Control Department in, 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 at each transport position. The control unit is configured to control the substrate processing apparatus to obtain, for each of the conveying positions, the etching rates at multiple locations near the end of the substrate on a concentric circle of the substrate from the measuring unit. The control unit is configured to control the substrate processing apparatus to generate approximate curves in the circumferential direction of the concentric circles based on the etching rate of each of the acquired transport positions. The control unit is configured to control the substrate processing apparatus to calculate a linear formula representing the movement direction of the substrate based on the approximate curve generated for each of the conveying positions. The control unit is configured to control the substrate processing apparatus to calculate the coordinates of the intersection points of each of the calculated linear equations.

2. The substrate processing apparatus according to claim 1, characterized in that, The approximate curve is generated by smoothing the etch rate at each of the acquired transport positions.

3. The substrate processing apparatus according to claim 1 or 2, characterized in that, The approximate curve is a sinusoidal approximate curve.

4. The substrate processing apparatus according to claim 1 or 2, characterized in that, The distance between the concentric circles and the end of the substrate is within 30mm.

5. The substrate processing apparatus according to claim 1 or 2, characterized in that, The control unit is configured to control the substrate processing apparatus to adjust the transport position of the substrate on the first mounting surface based on the calculated intersection coordinates.

6. A substrate processing apparatus comprising: A process module includes a stage and an edge ring. The stage is disposed inside a chamber and has a first mounting surface for mounting a substrate and a second mounting surface disposed on the outer periphery of the first mounting surface. The edge ring is mounted on the second mounting surface. The measuring unit measures the etching rate of the substrate; And the control department, in, The control unit is configured to control the substrate processing apparatus to etch the substrate under specific processing conditions; The control unit is configured to control the substrate processing apparatus to obtain from the measurement unit the etching rate at multiple locations near the end of the substrate on a concentric circle of the substrate. The control unit is configured to control the substrate processing apparatus to generate an approximate circumferential curve of the concentric circles based on the acquired etching rate. The control unit is configured to control the substrate processing apparatus to determine the direction of movement of the substrate based on the generated approximate curve. The control unit is configured to control the substrate processing apparatus to calculate the amount of movement of the substrate in the moving direction determined based on the etching rate or the approximate curve.

7. The substrate processing apparatus according to claim 6, characterized in that, The approximate curve is generated after smoothing the obtained etching rate.

8. The substrate processing apparatus according to claim 6 or 7, characterized in that, The approximate curve is a sinusoidal approximate curve.

9. The substrate processing apparatus according to claim 6 or 7, characterized in that, The distance between the concentric circles and the end of the substrate is within 30mm.

10. The substrate processing apparatus according to claim 6 or 7, characterized in that, The movement amount is calculated with reference to a database representing the relationship between the movement amount and the etching rate, or the relationship between the movement amount and the amplitude of the approximate curve.

11. The substrate processing apparatus according to claim 6 or 7, characterized in that, The control unit is configured to control the substrate processing apparatus to adjust the transport position of the substrate on the first mounting surface based on the moving direction and the moving amount.

12. A method for adjusting the position of a substrate transport, which is a substrate transport position adjustment method in a substrate processing apparatus, the substrate processing apparatus comprising: A process module includes a stage and an edge ring. The stage is disposed inside a chamber and has a first mounting surface for mounting a substrate and a second mounting surface disposed on the outer periphery of the first mounting surface. The edge ring is mounted on the second mounting surface. The measuring unit measures the etching rate of the substrate; And the control department, Under specific processing conditions, the substrate is transported to different transport positions on the first mounting surface, and the substrate is etched at each transport position; For each of the conveying positions, the etching rate at multiple locations near the end of the substrate on a concentric circle of the substrate is obtained from the measuring unit; Based on the etching rate of each of the acquired conveying positions, approximate curves in the circumferential direction of the concentric circles are generated. Based on the approximate curve generated for each of the aforementioned conveying positions, a linear expression representing the direction of movement of the substrate is calculated respectively; and The coordinates of the intersection points of each of the calculated linear equations are then calculated.

Images