JP7778239B2 - Substrate processing apparatus and substrate processing method - Google Patents

Description

The disclosed embodiments relate to a substrate processing apparatus and a substrate processing method.

Conventionally, single-substrate processing, in which substrates such as semiconductor wafers (hereinafter also referred to as wafers) are processed one by one, is performed by rotating the substrate while holding it in a substrate holder (see Patent Document 1).

Patent No. 5847661

This disclosure provides technology that can detect rotational slippage on a substrate.

A substrate processing apparatus according to one aspect of the present disclosure includes a substrate holding unit, an imaging device, and a control unit. The substrate holding unit holds and rotates a substrate to be processed. The imaging device images the substrate held by the substrate holding unit. The control unit controls each unit. The control unit also includes an execution unit, an acquisition unit, and a detection unit. The execution unit performs a series of substrate processing operations on the substrate brought in from outside and held by the substrate holding unit. The acquisition unit images the substrate after substrate processing using the imaging device to acquire image data. The detection unit detects any misalignment in the rotational direction of the substrate after substrate processing based on the acquired image data and stored reference data.

This disclosure makes it possible to detect rotational slippage on a substrate.

FIG. 1 is a schematic diagram showing a schematic configuration of a substrate processing system according to an embodiment. FIG. 2 is a schematic diagram showing an example of a specific configuration of a processing unit according to the embodiment. FIG. 3 is a block diagram illustrating an example of the configuration of the control device according to the embodiment. FIG. 4 is a diagram illustrating an example of the acquisition process according to the embodiment. FIG. 5 is a diagram illustrating an example of difference data according to the embodiment. FIG. 6 is a diagram showing the correlation between the X coordinate of the peak caused by the notch and the position of the notch in the rotational direction. FIG. 7 is a diagram illustrating the prediction process according to the embodiment. FIG. 8 is a diagram illustrating another example of the control process according to the embodiment. FIG. 9 is a diagram illustrating another example of the control process according to the embodiment. FIG. 10 is a flowchart showing an example of a procedure of a control process executed by the substrate processing system according to the embodiment. FIG. 11 is a flowchart showing an example of a procedure for a positional deviation detection process executed by the substrate processing system according to the embodiment. FIG. 12 is a flowchart showing an example of a procedure of a time-dependent change detection process executed by the substrate processing system according to the embodiment. FIG. 13 is a flowchart showing another example of the procedure of the control process executed by the substrate processing system according to the embodiment.

Embodiments of the substrate processing apparatus and substrate processing method disclosed herein will be described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to the embodiments described below. It should be noted that the drawings are schematic, and the dimensional relationships and ratios of each element may differ from reality. Furthermore, the drawings may include portions with different dimensional relationships and ratios.

Conventionally, single-wafer processing, in which substrates such as semiconductor wafers (hereinafter also referred to as wafers) are processed one by one, is performed while the substrate is held and rotated in a substrate holder. Therefore, if the substrate is not held firmly when processing is performed, the substrate may slip in the direction of rotation, resulting in insufficient substrate processing or problems such as large splashes of processing liquid onto the inner walls of the chamber.

On the other hand, while conventional technology could detect positional misalignment of a substrate placed on a substrate holder from a transport device, it was unable to detect slippage in the rotational direction that may occur after single-substrate processing.

Therefore, there is hope for the realization of technology that can overcome the above-mentioned problems and detect slippage in the rotational direction on a substrate.

<Outline of the substrate processing system>
First, a schematic configuration of a substrate processing system 1 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing the schematic configuration of the substrate processing system 1 according to an embodiment. The substrate processing system 1 is an example of a substrate processing apparatus. In the following, to clarify the positional relationship, mutually orthogonal X-axis, Y-axis, and Z-axis are defined, and the positive direction of the Z-axis is defined as the vertically upward direction.

As shown in Figure 1, the substrate processing system 1 includes a loading/unloading station 2 and a processing station 3. The loading/unloading station 2 and the processing station 3 are located adjacent to each other.

The loading/unloading station 2 comprises a FOUP placement section 11 and a transport section 12. The FOUP placement section 11 is loaded with multiple FOUPs H, each of which accommodates multiple substrates, in this embodiment, semiconductor wafers W (hereinafter referred to as wafers W), in a horizontal position.

The transfer section 12 is located adjacent to the FOUP placement section 11 and includes a substrate transfer device 13 and a transfer section 14. The substrate transfer device 13 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 13 is capable of moving horizontally and vertically and rotating around a vertical axis, and transfers the wafer W between the FOUP H and the transfer section 14 using the wafer holding mechanism.

The processing station 3 is located adjacent to the transport section 12. The processing station 3 includes a transport section 15 and a plurality of processing units 16. The plurality of processing units 16 are arranged side by side on both sides of the transport section 15.

The transfer section 15 has a substrate transfer device 17 inside. The substrate transfer device 17 has a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 is also capable of moving horizontally and vertically and rotating around a vertical axis, and uses the wafer holding mechanism to transfer the wafer W between the transfer section 14 and the processing unit 16.

The processing unit 16 performs a predetermined substrate processing on the wafer W transported by the substrate transport device 17.

The substrate processing system 1 also includes a control device 4. The control device 4 is, for example, a computer, and includes a control unit 18 and a memory unit 19. The memory unit 19 stores programs that control the various processes executed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the programs stored in the memory unit 19.

In addition, such a program may be recorded on a computer-readable storage medium and installed from that storage medium into the memory unit 19 of the control device 4. Examples of computer-readable storage media include hard disks (HDs), flexible disks (FDs), compact disks (CDs), magnetic optical disks (MOs), and memory cards.

In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 in the loading/unloading station 2 removes the wafer W from the FOUP H placed on the FOUP placement section 11 and places the removed wafer W on the transfer section 14. The wafer W placed on the transfer section 14 is then removed from the transfer section 14 by the substrate transfer device 17 in the processing station 3 and loaded into the processing unit 16.

After the wafer W is loaded into the processing unit 16 and processed by the processing unit 16, it is removed from the processing unit 16 by the substrate transfer device 17 and placed in the transfer section 14. The processed wafer W placed in the transfer section 14 is then returned to the FOUP H on the FOUP placement section 11 by the substrate transfer device 13.

<Configuration of processing unit>
Next, the configuration of the processing unit 16 according to the embodiment will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing an example of a specific configuration of the processing unit 16. As shown in Fig. 2, the processing unit 16 includes a chamber 20, a substrate processing section 30, a liquid supply section 40, a collection cup 50, and an imaging device 60.

The chamber 20 houses a substrate processing unit 30, a liquid supply unit 40, a collection cup 50, and an imaging device 60. An FFU (Fan Filter Unit) 21 is provided on the ceiling of the chamber 20. The FFU 21 creates a downflow within the chamber 20.

The substrate processing unit 30 comprises a substrate holding unit 31, a support unit 32, and a drive unit 33, and performs a given substrate processing on a placed wafer W. The substrate holding unit 31 holds the wafer W horizontally. The support unit 32 is a member extending vertically, with its base end rotatably supported by the drive unit 33 and its tip end supporting the substrate holding unit 31 horizontally. The drive unit 33 rotates the support unit 32 around a vertical axis.

The substrate processing unit 30 rotates the support column 32 using the drive unit 33, thereby rotating the substrate holding unit 31 supported by the support column 32, and thereby rotating the wafer W held by the substrate holding unit 31.

A holding member 31a that holds the wafer W from the side is provided on the upper surface of the substrate holding unit 31 provided in the substrate processing unit 30. The wafer W is held horizontally by this holding member 31a, slightly spaced from the upper surface of the substrate holding unit 31. The wafer W is held by the substrate holding unit 31 with the surface on which substrate processing will be performed facing upward.

The substrate holding unit 31 is not limited to holding the substrate by the holding member 31a, but may hold the wafer W horizontally, for example, by adsorbing the underside of the wafer W. Furthermore, the substrate holding unit 31 may be an electrostatic chuck or the like.

The liquid supply unit 40 supplies processing fluid to the wafer W. The liquid supply unit 40 includes nozzles 41a and 41b, an arm 42 that horizontally supports the nozzles 41a and 41b, and a pivoting and lifting mechanism 43 that pivots and raises and lowers the arm 42.

The nozzle 41a is connected to a processing liquid supply source 46a via a valve 44a and a flow regulator 45a. The processing liquid supply source 46a is a tank that stores processing liquid. Such processing liquid is used, for example, for liquid processing of the wafer W (e.g., etching processing, cleaning processing, etc.).

Nozzle 41b is connected to DIW supply source 46b via valve 44b and flow regulator 45b. DIW supply source 46b is, for example, a tank that stores DIW (Deionized Water). This DIW is used, for example, for rinsing wafers W.

In the example of Figure 2, the liquid supply unit 40 supplies a processing liquid and a rinse liquid (DIW) to the wafer W, but the present disclosure is not limited to such an example and may be configured to supply other chemical liquids to the wafer W.

The collection cup 50 is positioned to surround the substrate holder 31 and collects the processing liquid scattered from the wafer W due to the rotation of the substrate holder 31. A drain port 51 is formed in the bottom of the collection cup 50, and the processing liquid collected by the collection cup 50 is discharged from the drain port 51 to the outside of the processing unit 16. In addition, an exhaust port 52 is formed in the bottom of the collection cup 50, which discharges the gas supplied from the FFU 21 to the outside of the processing unit 16.

The imaging device 60 is positioned, for example, near the peripheral edge of the wafer W and above the wafer W, and captures an image of the wafer W held by the substrate holder 31. The imaging device 60 is positioned, for example, at a position where it can capture an image of the contour Wa of the outer peripheral edge of the wafer W (see Figure 4).

<Detection process details>
Next, details of the detection process according to the embodiment will be described with reference to Fig. 3 to Fig. 7. Fig. 3 is a block diagram showing an example of the configuration of the control device 4 according to the embodiment. As shown in Fig. 3, the control device 4 includes a control unit 18 and a storage unit 19.

The control device 4 is also connected to the above-mentioned substrate processing unit 30, liquid supply unit 40, and imaging device 60. In addition to the functional units shown in Figure 3, the control device 4 may also have various functional units that known computers have, such as various input devices and audio output devices.

The memory unit 19 is realized by, for example, a semiconductor memory element such as RAM or flash memory, or a storage device such as a hard disk or optical disk. The memory unit 19 has a reference data memory unit 19a, a captured image memory unit 19b, and a positional deviation angle memory unit 19c. Details of these memory units will be described later. The memory unit 19 also stores information used for various processes in the control unit 18.

The control unit 18 is realized, for example, by a CPU, MPU (Micro Processing Unit), GPU (Graphics Processing Unit), etc., by executing programs stored in the memory unit 19 using RAM as a working area.

The control unit 18 may also be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

The control unit 18 has an execution unit 18a, an acquisition unit 18b, a creation unit 18c, a detection unit 18d, a notification unit 18e, and a prediction unit 18f, and realizes or executes the functions and actions of the control processing described below. Note that the internal configuration of the control unit 18 is not limited to the configuration shown in Figure 3, and may be any other configuration that performs the control processing described below.

The execution unit 18a performs a series of substrate processing operations on a wafer W that has been brought in from outside the processing unit 16 and held by the substrate holder 31. For example, the execution unit 18a controls the substrate processing unit 30 and other components to rotate the wafer W at a given rotation speed, and controls the liquid supply unit 40 and other components to supply a given amount of processing liquid onto the wafer W, in accordance with a recipe specified by an operator or the like.

The execution unit 18a also performs a rinse process using DIW on the wafer W after the liquid processing using the processing liquid has been completed. Furthermore, the execution unit 18a also performs a drying process such as spin drying on the wafer W after the rinse processing has been completed.

The acquisition unit 18b acquires image data by capturing an image of the wafer W after the execution unit 18a has performed substrate processing using the imaging device 60. The acquisition unit 18b may also acquire separate image data by capturing an image of the wafer W before the execution unit 18a has performed substrate processing using the imaging device 60. Details of the acquisition process performed by the acquisition unit 18b will be described with reference to FIG. 4.

Figure 4 is a diagram for explaining an example of an acquisition process according to an embodiment. As shown in (a) of Figure 4, the acquisition unit 18b acquires an image of the wafer W held by the substrate holder 31 (see Figure 2) using the imaging device 60 (see Figure 2) before substrate processing.

This captured image before substrate processing includes, for example, the contour Wa of the outer peripheral edge of the wafer W and the notch N formed at the outer peripheral edge of the wafer W. This image data before substrate processing is stored, for example, as reference data in the reference data storage unit 19a of the storage unit 19.

Furthermore, as shown in FIG. 4(b), the acquisition unit 18b captures an image of the wafer W held by the substrate holder 31 using the imaging device 60 after substrate processing, and acquires an image of the wafer W. This captured image after substrate processing also records the contour Wa of the outer peripheral edge of the wafer W and the notch N formed at the outer peripheral edge of the wafer W.

In addition, various image processing (e.g., edge detection processing) may be performed on these captured images to clarify the contour Wa and notch N.

Returning to the explanation of Figure 3, the creation unit 18c creates differential data of the contour Wa of the outer peripheral edge of the wafer W using the image data of the wafer W after substrate processing acquired by the acquisition unit 18b and the reference data stored in the reference data storage unit 19a.

The reference data used by the creation unit 18c during the creation process is, for example, image data of the wafer W before substrate processing acquired by the acquisition unit 18b. Details of this creation process will be described with reference to Figures 4 and 5.

The creation unit 18c first identifies the X and Y coordinates of multiple points at which the contour Wa is located, which are stored in the reference data (for example, image data of the wafer W before substrate processing). Similarly, the creation unit 18c also identifies the X and Y coordinates of multiple points at which the contour Wa is located, which are stored in the image data of the wafer W after substrate processing.

Next, at the same X coordinate value, the creation unit 18c subtracts the Y coordinate value of the contour Wa in the image data of the wafer W after substrate processing from the Y coordinate value of the contour Wa in the image data of the wafer W before substrate processing. In other words, at the same X coordinate value, the creation unit 18c takes the difference between the Y coordinate value of the contour Wa before substrate processing and the Y coordinate value of the contour Wa after substrate processing.

Here, if there is no rotational slippage on the wafer W after substrate processing, the contour Wa of the wafer W before substrate processing and the contour Wa of the wafer W after substrate processing will basically all coincide. Therefore, in this case, for the same X coordinate value, the Y coordinate value of the contour Wa before substrate processing and the Y coordinate value of the contour Wa after substrate processing will be approximately equal (i.e., the difference will be approximately zero).

On the other hand, as shown in Figure 4, if rotational slippage occurs in the wafer W after substrate processing, the contour Wa of the wafer W before substrate processing and the contour Wa of the wafer W after substrate processing will no longer coincide at the X coordinate where the notch N is located.

Figure 5 shows an example of differential data relating to an embodiment, and is a diagram showing an example of differential data when two image data such as those shown in Figure 4 are obtained before and after substrate processing. Note that Figure 5 shows data in which the difference trends have been smoothed using the moving average method.

As shown in Figure 5, peak P1 located at X = X1 is a peak caused by notch N before substrate processing (see Figure 4(a)). This is because, at X = X1, the value of Y is large before substrate processing because notch N is located, whereas after substrate processing, the value of Y is small because notch N is not located.

In the example of Figure 5, the negative peak P2 located at X = X2 is a peak caused by the notch N after substrate processing (see Figure 4 (b)). This is because, at X = X2, the notch N is not located before substrate processing, so the value of Y is small, whereas after substrate processing, the notch N is located, so the value of Y is large.

Returning to the explanation of Figure 3, the detection unit 18d detects the positional deviation in the rotational direction of the wafer W after substrate processing based on the image data acquired after substrate processing and the reference data stored in the reference data storage unit 19a.

For example, as shown in Figure 5, if the detection unit 18d detects a peak P1 greater than or equal to a given threshold A and a peak P2 less than or equal to a given threshold -A in the differential data, it can determine that a rotational misalignment has occurred in the wafer W after substrate processing.

Furthermore, the detection unit 18d can estimate the amount of misalignment of the notch N after substrate processing, i.e., the amount of positional misalignment in the rotational direction, based on the difference between the X values (here, X1 and X2) at the two peaks P1 and P2 detected in the differential data.

Figure 6 shows the correlation between the X-coordinate of the peak caused by notch N and the position in the rotational direction of the wafer W. Note that in the data shown in Figure 6, the position in the rotational direction of the wafer W when notch N is located approximately in the center of the image data (for example, as shown in Figure 4(a)) is defined as 180 (deg).

As shown in Figure 6, in the image data of the contour Wa, it can be seen that there is a very high correlation between the X value of the peak caused by the notch N and the position in the rotational direction of the wafer W.

The detection unit 18d therefore calculates the position of the notch N before substrate processing (i.e., the position in the rotational direction of the wafer W) shown in Figure 5 based on the correlation shown in Figure 6. Furthermore, the detection unit 18d calculates the position of the notch N after substrate processing (i.e., the position in the rotational direction of the wafer W) based on the correlation shown in Figure 6.

The detection unit 18d can then calculate the rotational position deviation angle of the wafer W after substrate processing by taking the difference between the calculated rotational position of the wafer W before substrate processing and the rotational position of the wafer W after substrate processing.

As described above, in the embodiment, rotational slippage of the wafer W can be detected by detecting the rotational positional deviation of the wafer W based on image data after substrate processing.

In the present disclosure, the correlation used to calculate the rotational position of the wafer W is not limited to the linear correlation shown in Figure 6. For example, data storing the correlation between the rotational position of the wafer W and the peak X value may be prepared in advance as a table, and the table may be referenced when calculating the rotational position of the wafer W.

Returning to the explanation of Figure 3, the notification unit 18e notifies the operator that a positional deviation has occurred in the wafer W when the positional deviation angle of the wafer W calculated by the detection unit 18d is equal to or greater than a given threshold value. This allows the operator to recognize an abnormal state of the substrate holder 31.

In addition, the notification unit 18e may store captured images of the wafer W during processing if the positional deviation angle of the wafer W is equal to or greater than a given threshold value. Such captured images may be, for example, videos, and are stored in the captured image storage unit 19b of the storage unit 19.

Furthermore, the notification unit 18e may associate the captured image during substrate processing stored in the captured image memory unit 19b as described above with log information indicating that an abnormal condition has been notified for the same wafer W.

In this way, by storing images taken during processing of a wafer W for which slippage in the rotational direction has been detected in the memory unit 19, the operator can later review the details of the defect using the stored images. Furthermore, by associating the images taken during substrate processing with log information indicating that an abnormal condition has been reported, the operator can easily review the images taken during the abnormality.

In addition to the above detection process, the detection unit 18d calculates the rotational misalignment angle for each of multiple wafers W that are subsequently loaded into the processing unit 16, and stores such misalignment angles in the misalignment angle memory unit 19c of the memory unit 19.

The prediction unit 18f then predicts the holding state of the substrate holding unit 31 based on the changes over time in the multiple positional deviation angles stored in the positional deviation angle memory unit 19c. Figure 7 is a diagram for explaining the prediction process according to the embodiment.

As shown in Figure 7, in the positional deviation angle memory unit 19c of the embodiment, data for multiple wafers W are plotted in an XY space, where the horizontal axis is time (or the number of processed wafers W) and the vertical axis is the value of the positional deviation angle of the wafer W.

The prediction unit 18f predicts the holding state of the substrate holding unit 31 based on the change in the positional deviation angle over time as shown in Figure 7. The prediction unit 18f predicts the holding state of the substrate holding unit 31, for example, by linear regression analysis.

For example, in the example of Figure 7, the time course of the misalignment angle regresses to a straight line of misalignment angle = 0 until time T0. In other words, in the example of Figure 7, there is no noticeable change in the misalignment angle of the wafer W until time T0, and it is estimated that a good holding state is maintained.

On the other hand, after time T0, the change in the positional deviation angle over time reverts to a sloped straight line L. Therefore, the prediction unit 18f predicts at time T1 that the holding state will become abnormal at time T2, which is the intersection point between this straight line L and the upper (or lower) limit of the positional deviation angle at which the holding state is considered to be maintained in a good condition.

In this way, in the embodiment, the holding state of the substrate holding unit 31 can be accurately predicted based on the change in the positional deviation angle over time. Therefore, according to the embodiment, based on the obtained prediction, the worker can prepare parts such as the substrate holding unit 31 in advance and plan maintenance.

In the example of Figure 7, the prediction unit 18f predicts the holding state of the substrate holding unit 31 using linear regression analysis, but the present disclosure is not limited to such an example, and the holding state of the substrate holding unit 31 may be predicted using various analytical methods.

<Another example of control processing>
Next, another example of the various processes in the control unit 18 will be described with reference to Figures 8 and 9. In the above embodiment, an example has been shown in which misalignment in the rotational direction is detected based on the position of the notch N (see Figure 4) shown in image data captured by the imaging device 60, but the present disclosure is not limited to this example.

Figure 8 is a diagram illustrating another example of a control process according to an embodiment. In the example of Figure 8, slippage in the rotational direction on the wafer W is detected based on a line C of a pattern shape formed on the surface of the wafer W.

For example, the detection unit 18d (see Figure 3) calculates the rotational position of the wafer W before substrate processing based on the orientation of line C (e.g., the inclination angle of line C) of the pattern shape shown on the wafer W before substrate processing shown in (a) of Figure 8.

Furthermore, the detection unit 18d calculates the position in the rotational direction of the wafer W before substrate processing based on the orientation (e.g., the inclination angle of line C) of the pattern shape line C shown on the wafer W after substrate processing shown in (b) of Figure 8. The pattern shape line C shown on the wafer W is detected, for example, by a Hough transformation process.

In this case, the inclination angle of line C and the position in the rotational direction (rotation angle) of the wafer W do not necessarily coincide. Therefore, it is advisable to prepare in advance a table containing data that stores the correlation between the inclination angle of line C at a given location on the wafer W and the position in the rotational direction (rotation angle) of the wafer W, and refer to this table when calculating the position in the rotational direction of the wafer W from the inclination angle of line C.

The detection unit 18d can then calculate the rotational position deviation angle of the wafer W after substrate processing by taking the difference between the calculated rotational position of the wafer W before substrate processing and the rotational position of the wafer W after substrate processing.

In the present disclosure, the indicator for detecting the rotational position of the wafer W is not limited to the notch N or the pattern-shaped line C. For example, the rotational position of the wafer W may be detected based on the position of an inscription such as a lot number marked on the back side of the wafer W. In this case, the imaging device 60 should be positioned so that it can capture an image of the back side of the wafer W.

Furthermore, in the above embodiment, image data of the wafer W before substrate processing is used as reference data, but the present disclosure is not limited to such an example. Figure 9 is a diagram for explaining another example of the detection process according to the embodiment. Note that in Figure 9, the contour Wa of the outer peripheral edge of the wafer W and the notch N are shown with dashed lines for ease of understanding.

In the example of Figure 9, a given elliptical approximation curve O is used as reference data. In this example, the detection unit 18d calculates the absolute position of the notch N after substrate processing (i.e., the absolute position in the rotational direction of the wafer W) based on a given correlation by taking the difference between the elliptical approximation curve O and the contour Wa of the wafer W after substrate processing. This also makes it possible to detect slippage in the rotational direction of the wafer W.

Furthermore, by using the detection process of the absolute position of the notch N as described above, it is possible to perform rotational alignment of the wafer W (so-called alignment process) in the processing unit 16.

Specifically, for example, the control unit 18 uses the imaging device 60 to capture an image of the wafer W that has been loaded and held by the substrate holder 31, and based on the captured image data of the wafer W, calculates the difference between the contour Wa of the wafer W in the captured image data and the elliptical approximation curve O. This allows the control unit 18 to determine the absolute position of the wafer W in the rotational direction.

Next, the control unit 18 determines whether the absolute position of the wafer W in the rotational direction is aligned with a given set position. If the absolute position of the wafer W in the rotational direction is aligned with a given set position, the control unit 18 determines that the alignment of the wafer W is aligned, and ends the series of alignment processes.

On the other hand, if the absolute rotational position of the wafer W deviates from a given set position, the control unit 18 returns the wafer W to the substrate transport device 17 and adjusts the rotational position of the substrate holding unit 31.

At this time, the control unit 18 adjusts the rotational position of the substrate holding unit 31 based on the absolute rotational position of the wafer W detected above so that the absolute rotational position of the wafer W is within a given range.

Next, the control unit 18 uses the imaging device 60 to image the wafer W that has been loaded again and held by the substrate holding unit 31, and based on the image data of the wafer W obtained, calculates the difference between the contour Wa of the wafer W in the image data and the elliptical approximation curve O. As a result, the control unit 18 again determines the absolute position of the wafer W in the rotational direction.

Next, the control unit 18 again determines whether the absolute position of the wafer W in the rotational direction is aligned with the given set position. The control unit 18 then repeats the above process until the absolute position of the wafer W in the rotational direction is aligned with the given set position.

As a result, in the embodiment, the rotational alignment of the wafer W can be performed in the processing unit 16. Therefore, according to the embodiment, the rotational alignment of the wafer W can be performed without using a dedicated alignment adjustment device, thereby reducing the cost of the substrate processing system 1.

The substrate processing apparatus (substrate processing system 1) according to the embodiment includes a substrate holding unit 31, an imaging device 60, and a control unit 18. The substrate holding unit 31 holds and rotates the substrate (wafer W) to be processed. The imaging device 60 images the substrate (wafer W) held by the substrate holding unit 31. The control unit 18 controls each unit. The control unit 18 also includes an execution unit 18a, an acquisition unit 18b, and a detection unit 18d. The execution unit 18a performs a series of substrate processing operations on a substrate (wafer W) that has been brought in from outside and held by the substrate holding unit 31. The acquisition unit 18b acquires image data by capturing an image of the substrate (wafer W) after the substrate processing using the imaging device 60. The detection unit 18d detects rotational misalignment of the substrate (wafer W) after the substrate processing based on the acquired image data and stored reference data. This makes it possible to detect rotational slippage of the wafer W.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the detection unit 18d calculates the rotational positional deviation angle of the substrate (wafer W) after substrate processing based on the image data and the reference data. This allows for accurate detection of rotational slippage of the wafer W.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the acquisition unit 18b acquires separate image data by capturing an image of a substrate (wafer W) that has been brought in from outside and held by the substrate holder 31 before a series of substrate processing operations. The acquisition unit 18b also stores the acquired separate image data as reference data. This makes it possible to detect rotational slippage of the wafer W that occurs during substrate processing.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the control unit 18 further includes a creation unit 18c that uses image data and reference data to create differential data of the contour Wa of the outer peripheral edge of the substrate (wafer W). Furthermore, the detection unit 18d detects the positional deviation in the rotational direction of the substrate (wafer W) after substrate processing based on the differential data. This allows for accurate detection of slippage in the rotational direction of the wafer W.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the detection unit detects the positional deviation of the substrate in the rotational direction after substrate processing based on the pattern shape of the substrate surface shown in the image data and the pattern shape of the substrate surface shown in the reference data. This makes it possible to detect slippage in the rotational direction of the wafer W.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the control unit 18 further includes a notification unit 18e that notifies the operator that a positional deviation has occurred in the substrate (wafer W) when the calculated positional deviation angle is equal to or greater than a given threshold value. This allows the operator to recognize an abnormal state of the substrate holder 31.

Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the detection unit 18d stores the positional deviation angle in the memory unit 19 when the calculated positional deviation angle is less than a given threshold value. This allows the change in the positional deviation angle over time to be stored in the memory unit 19.

Furthermore, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the control unit 18 further includes a prediction unit 18f that predicts the holding state of the substrate holding unit 31 based on changes over time in the stored multiple positional deviation angles. This allows the holding state of the substrate holding unit 31 to be predicted with high accuracy.

In addition, in the substrate processing apparatus (substrate processing system 1) according to the embodiment, the acquisition unit 18b acquires image data of a substrate (wafer W) held by the substrate holding unit 31 before or after substrate processing. The detection unit 18d detects the rotational position (absolute position) of the substrate (wafer W) relative to the substrate holding unit 31 based on the acquired image data and stored reference data. This allows the rotational alignment of the wafer W to be performed without using a dedicated alignment adjustment device, thereby reducing the cost of the substrate processing system 1.

<Control process procedure>
Next, the procedure of the control process according to the embodiment will be described with reference to Fig. 10 to Fig. 13. Fig. 10 is a flowchart showing an example of the procedure of the control process executed by the substrate processing system 1 according to the embodiment.

In the control process of the embodiment, first, the control unit 18 holds the wafer W loaded into the processing unit 16 using the substrate holding unit 31 (step S101).

Next, the control unit 18 stores the reference data (step S102). For example, the control unit 18 images the wafer W before substrate processing using the imaging device 60 and stores the image data of this wafer W as reference data. This reference data is stored, for example, in the reference data storage unit 19a of the storage unit 19.

Next, the control unit 18 rotates the wafer W held by the substrate holding unit 31 while supplying processing liquid, rinsing liquid, etc. to the wafer W, thereby performing a given process on the wafer W (step S103).

Next, the control unit 18 performs a positional deviation detection process to detect the positional deviation in the rotational direction of the wafer W held by the substrate holding unit 31 (step S104). Details of this positional deviation detection process will be described later.

Finally, the control unit 18 performs a time-dependent change detection process to detect changes over time in the holding state of the wafer W held by the substrate holding unit 31 (step S105), and ends the series of control processes. Details of this time-dependent change detection process will be described later.

Figure 11 is a flowchart showing an example of the procedure for a positional deviation detection process performed by the substrate processing system 1 according to the embodiment. In this positional deviation detection process, the control unit 18 first acquires image data of the processed wafer W held by the substrate holding unit 31 using the imaging device 60 (step S201).

Next, the control unit 18 creates differential data of the contour Wa of the outer peripheral edge of the wafer W using image data of the wafer W after substrate processing and the reference data stored in the reference data memory unit 19a (step S202).

Next, the control unit 18 determines whether two peaks P1 and P2 are detected in the difference data of the created contour Wa (step S203). If two peaks P1 and P2 are not detected in the difference data (step S203, No), the control unit 18 determines that no slippage in the rotational direction has occurred on the wafer W (step S204), and terminates the series of positional deviation detection processes.

On the other hand, if two peaks P1 and P2 are detected in the differential data (step S203, Yes), the control unit 18 calculates the positional deviation angle of the wafer W based on the two detected peaks P1 and P2 (step S205).The control unit 18 then determines whether the calculated positional deviation angle of the wafer W is within a given range (step S206).

If the positional deviation angle of the wafer W is within a given range (step S206, Yes), the series of positional deviation detection processes is terminated. On the other hand, if the positional deviation angle of the wafer W is not within the given range (step S206, No), the control unit 18 notifies the fact that a positional deviation has occurred in the wafer W held by the substrate holding unit 31 (step S207).

Then, the control unit 18 stores the captured image of the wafer W during substrate processing captured by the imaging device 60 in the captured image memory unit 19b of the memory unit 19 (step S208), and completes the series of positional deviation detection processes.

Figure 12 is a flowchart showing an example of the procedure for detecting changes over time performed by the substrate processing system 1 of the embodiment.

In this time-dependent change detection process, first, the control unit 18 stores the positional deviation angle of the wafer W detected in the processing of the above-mentioned step S205 in the positional deviation angle memory unit 19c of the memory unit 19 (step S301).

In addition, if it is determined in the processing of the above-mentioned step S203 that no slippage in the rotational direction has occurred on the wafer W, the positional deviation angle of the wafer W is stored as zero in the positional deviation angle memory unit 19c of the memory unit 19.

Next, the control unit 18 performs linear regression analysis of the change in positional deviation angle over time in the XY space in which the change in positional deviation angle over time for multiple wafers W is plotted (step S302).

Next, the control unit 18 determines whether there is a significant difference in the slope of the line created by the linear regression analysis (step S303). If it is determined that there is a significant difference in the slope of the line created by the linear regression analysis (step S303, Yes), the control unit 18 predicts the timing at which the positional deviation angle of the wafer W will deviate from the allowable range (step S304).

Furthermore, the control unit 18 notifies the operator of the predicted deviation timing (step S305) and terminates the series of time-dependent change detection processes. On the other hand, if it is determined that there is no significant difference in the slope of the line created by the linear regression analysis (step S303, No), the series of time-dependent change detection processes terminates.

Figure 13 is a flowchart showing another example of the procedure of the control process executed by the substrate processing system 1 according to the embodiment. In this control process, alignment processing of the wafer W is performed in the processing unit 16.

In another example of control processing, the control unit 18 first holds the wafer W that has been loaded into the processing unit 16 in the substrate holding unit 31 (step S401). Then, the control unit 18 acquires image data of the wafer W held in the substrate holding unit 31 using the imaging device 60 (step S402).

Next, the control unit 18 uses the image data of the wafer W after substrate processing and the reference data stored in the reference data storage unit 19a to create differential data of the contour Wa of the outer peripheral edge of the wafer W (step S403). In this case, for example, an elliptical approximation curve O is used as the reference data.

Next, the control unit 18 detects the absolute position in the rotational direction of the wafer W held by the substrate holding unit 31 based on the created difference data (step S404).The control unit 18 then determines whether the absolute position in the rotational direction of the wafer W is within a given range (step S405).

If the absolute position of the wafer W in the rotational direction is within the given range (step S405, Yes), the control process ends. On the other hand, if the absolute position of the wafer W in the rotational direction is not within the given range (step S405, No), the control unit 18 returns the wafer W from the substrate holding unit 31 to the substrate transfer device 17 (step S406).

Furthermore, the control unit 18 adjusts the rotational position of the substrate holder 31 based on the absolute rotational position of the wafer W detected in step S404 so that the absolute rotational position of the wafer W is within a given range (step S407). Then, the process returns to step S401.

The substrate processing method according to the embodiment includes a holding step (step S101), an execution step (step S103), an acquisition step (step S201), and a detection step (steps S203 to S205). In the holding step (step S101), a substrate (wafer W) carried in from outside is held by the substrate holder 31. In the execution step (step S103), a series of substrate processes are performed on the substrate (wafer W). In the acquisition step (step S201), the substrate (wafer W) after the substrate processing is imaged by the imaging device 60 to acquire image data. In the detection step (steps S203 to S205), misalignment in the rotational direction of the substrate (wafer W) after the substrate processing is detected based on the acquired image data and stored reference data. This makes it possible to detect slippage in the rotational direction of the wafer W.

In addition, in the substrate processing method according to the embodiment, the detection process (steps S203 to S205) calculates the rotational misalignment angle of the substrate (wafer W) after substrate processing based on the image data and reference data. This allows for accurate detection of rotational slippage of the wafer W.

The substrate processing method according to the embodiment further includes a storing step (step S102). In the storing step (step S102), the substrate (wafer W) that has been brought in from outside and held by the substrate holder 31 is imaged by the imaging device 60 before a series of substrate processing steps to obtain separate image data, and the obtained separate image data is stored as reference data. This makes it possible to detect slippage in the rotational direction of the wafer W that occurs during substrate processing.

The substrate processing method according to the embodiment further includes a notification step (step S207). The notification step (step S207) notifies the operator that a positional deviation has occurred in the substrate (wafer W) if the calculated positional deviation angle is equal to or greater than a given threshold value. This allows the operator to recognize the abnormal state of the substrate holder 31.

Furthermore, in the substrate processing method according to the embodiment, the detection process (steps S203 to S205) stores the positional deviation angle in the memory unit 19 if the calculated positional deviation angle is less than a given threshold value. This allows the change in the positional deviation angle over time to be stored in the memory unit 19.

The substrate processing method according to the embodiment further includes a prediction step (step S304). The prediction step (step S304) predicts the holding state of the substrate holding unit 31 based on the changes over time in the stored multiple positional deviation angles. This allows the holding state of the substrate holding unit 31 to be predicted with high accuracy.

The above describes an embodiment of the present disclosure, but the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the spirit thereof. For example, the above embodiment describes an example in which reference data, captured images, changes in positional deviation angle over time, etc. are stored in the memory unit 19 provided in the control device 4 of the substrate processing system 1, but the present disclosure is not limited to such an example. For example, in the present disclosure, reference data, captured images, changes in positional deviation angle over time, etc. may be stored in a separate storage device connected to the control device 4 via a network.

The embodiments disclosed herein should be considered in all respects as illustrative and not restrictive. Indeed, the above-described embodiments may be embodied in a variety of forms. Furthermore, the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

W: Wafer (an example of a substrate)
Wa Outline 1 Substrate processing system (an example of a substrate processing apparatus)
4 Control device 16 Processing unit 18 Control unit 18a Execution unit 18b Acquisition unit 18c Creation unit 18d Detection unit 18e Notification unit 18f Prediction unit 19 Storage unit 19a Reference data storage unit 19b Captured image storage unit 19c Position deviation angle storage unit 31 Substrate holding unit 60 Imaging device

Claims (15)

a substrate holder that holds and rotates a substrate to be processed;
an imaging device that images the substrate held by the substrate holding unit;
a control unit that controls each unit;
Equipped with
The control unit
an execution unit that executes a series of substrate processing operations on the substrate that is carried in from outside and held by the substrate holder;
an acquisition unit that acquires image data by capturing an image of the substrate after the substrate processing using the imaging device;
a detection unit that detects a positional deviation in a rotational direction of the substrate after the substrate processing based on the acquired image data and stored reference data;
A substrate processing apparatus having: The substrate processing apparatus according to claim 1 , wherein the detection unit calculates a positional deviation angle of the substrate in a rotational direction after the substrate processing based on the image data and the reference data. The substrate processing apparatus according to claim 1 , wherein the acquisition unit acquires another image data by capturing an image of the substrate carried in from outside and held in a substrate holding unit before a series of substrate processing operations, and stores the acquired another image data as the reference data. The control unit
a creating unit that creates difference data of the contour of the outer peripheral edge of the substrate using the image data and the reference data,
4. The substrate processing apparatus according to claim 1, wherein the detection unit detects a positional deviation of the substrate in a rotational direction after the substrate processing based on the difference data. 4. The substrate processing apparatus according to claim 1, wherein the detection unit detects a positional deviation in the rotational direction of the substrate after substrate processing based on a pattern shape of the surface of the substrate shown in the image data and a pattern shape of the surface of the substrate shown in the reference data. The control unit
The substrate processing apparatus according to claim 2 , further comprising a notification unit that notifies the user that a positional deviation has occurred in the substrate when the calculated positional deviation angle is equal to or greater than a given threshold value. The substrate processing apparatus according to claim 2 , wherein the detection unit stores the calculated positional deviation angle in a storage unit when the calculated positional deviation angle is less than a given threshold value. The control unit
The substrate processing apparatus according to claim 7 , further comprising a prediction unit that predicts a holding state of the substrate holder based on changes over time of the stored plurality of positional deviation angles. the acquisition unit acquires image data of the substrate held by the substrate holder before or after substrate processing;
The substrate processing apparatus according to claim 1 , wherein the detection unit detects the position of the substrate in the rotational direction relative to the substrate holder based on the acquired image data and the stored reference data. a step of holding a substrate carried in from outside by a substrate holding unit;
performing a series of substrate processes on the substrate;
a step of capturing an image of the substrate after the substrate processing using an imaging device to acquire image data;
detecting a positional deviation in a rotational direction of the substrate after substrate processing based on the acquired image data and stored reference data;
A substrate processing method comprising: The substrate processing method according to claim 10 , wherein the detecting step calculates a positional deviation angle of the substrate in a rotational direction after the substrate processing based on the image data and the reference data. The substrate processing method according to claim 10, further comprising the step of capturing an image of the substrate, which has been brought in from outside and held in a substrate holding unit, with the imaging device before a series of substrate processing operations to obtain different image data, and storing the obtained different image data as the reference data. The substrate processing method according to claim 11 , further comprising the step of notifying the occurrence of positional deviation of the substrate when the calculated positional deviation angle is equal to or greater than a given threshold value. The substrate processing method according to claim 11 or 13, wherein the detecting step stores the calculated positional deviation angle in a storage unit when the calculated positional deviation angle is less than a given threshold value. The substrate processing method according to claim 14 , further comprising the step of predicting a holding state of the substrate holder based on changes over time of the stored plurality of positional deviation angles.