Information acquisition system for substrate processing apparatus, arithmetic device, and information acquisition method for substrate processing apparatus

Abstract

To prevent the occurrence of processing defects caused by a nozzle or a cup being placed at an inappropriate position relative to a substrate in a substrate processing apparatus that performs liquid processing on the substrate. [Solution] In an information acquisition system for acquiring information about a substrate processing apparatus comprising a substrate holding unit that holds and rotates a substrate, a nozzle that supplies processing liquid to the surface of the rotating substrate, and a cup that surrounds the substrate held in the substrate holding unit, the information acquisition system is configured to comprise an information acquisition body that is held by the substrate holding unit in place of the substrate, an imaging unit that is provided on the information acquisition body for imaging the cup and acquiring image data, and an acquisition unit that acquires information about the height of the cup based on the image data.

Description

[Technical Field]

[0001] The present disclosure relates to an information acquisition system for a substrate processing apparatus, a computing device, and an information acquisition method for a substrate processing apparatus. [Background technology]

[0002] In the manufacturing process of semiconductor devices, semiconductor wafers (hereinafter referred to as wafers) are stored in a carrier and transported to a substrate processing apparatus for processing. Examples of such processing include liquid processing such as forming a coating film by supplying a coating liquid and developing. During such liquid processing, a processing liquid is supplied from a nozzle to the wafer stored in a cup. Patent Document 1 describes a developing apparatus that includes a cup with an annular protrusion facing the underside of the wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-13932 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure aims to prevent processing defects caused by a nozzle or cup being positioned in an inappropriate position relative to a substrate in a substrate processing apparatus that performs liquid processing on a substrate. [Means for solving the problem]

[0005] The present disclosure provides an information acquisition system for acquiring information about a substrate processing apparatus including a substrate holding unit that holds and rotates a substrate, a nozzle that supplies a processing liquid to a surface of the rotating substrate, and a cup that surrounds the substrate held by the substrate holding unit, the information acquisition system comprising: an information-acquiring body held by the substrate holding unit in place of the substrate; an imaging unit provided in the information acquisition body for capturing an image of the cup and acquiring image data; an acquisition unit that acquires information about the height of the cup based on the image data; Equipped with.

[0006] Another information acquisition system of the present disclosure is an information acquisition system for acquiring information about a substrate processing apparatus including a substrate holding unit that holds and rotates a substrate, a nozzle that supplies a processing liquid to a surface of the rotating substrate, and a cup that surrounds the substrate held by the substrate holding unit, an information-acquiring body held by the substrate holding unit in place of the substrate; an imaging unit provided in the information acquisition body for capturing an image of the nozzle and acquiring image data; an acquisition unit that acquires a second distance between the substrate and the nozzle based on the number of pixels between the nozzle in the image data and a predetermined reference height of the image data; Equipped with. [Effects of the Invention]

[0007] The present disclosure can prevent processing defects caused by a nozzle or cup being placed in an inappropriate position relative to a substrate in a substrate processing apparatus that performs liquid processing on a substrate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view of a substrate processing apparatus that constitutes an information acquisition system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a vertical sectional front view of a resist film forming module included in the substrate processing apparatus. [Figure 3] FIG. 2 is a plan view of the resist film forming module. [Figure 4] FIG. 2 is a side view showing a cup and a thinner supply nozzle that constitute the resist film forming module. [Figure 5] FIG. 2 is an explanatory diagram showing an inspection wafer and a computing device that constitute the information acquisition system. [Figure 6] FIG. 2 is a plan view of the test wafer. [Figure 7] FIG. 10 is an explanatory diagram showing an image of the top surface of the annular protrusion provided on the cup. [Figure 8] FIG. 10 is an explanatory diagram for explaining a preparation process for performing an inspection. [Figure 9] FIG. 10 is a graph showing data obtained in the preparation step. [Figure 10] FIG. 10 is an explanatory diagram for explaining a preparation process for performing an inspection. [Figure 11] FIG. 10 is an explanatory diagram showing an image acquired in a preparation step. [Figure 12] FIG. 10 is an explanatory diagram showing an image of a side surface of a nozzle provided in the resist film forming module. [Figure 13] FIG. 10 is a vertical cross-sectional side view showing another example of the configuration of the cup. [Figure 14] FIG. 10 is a vertical cross-sectional side view showing another configuration example of the resist film forming module. [Figure 15] FIG. 10 is an explanatory diagram for explaining a preparation process for performing an inspection. [Figure 16] FIG. 10 is an explanatory diagram for explaining a preparation process for performing an inspection. [Figure 17] FIG. 10 is an explanatory diagram for explaining a preparation process for performing an inspection. [Figure 18] 10 is an explanatory diagram for explaining detection of the height of an intermediate guide part constituting the resist film forming module. FIG. [Figure 19] FIG. 10 is a plan view showing another example of the test wafer and the cup. DETAILED DESCRIPTION OF THE INVENTION

[0009] [First embodiment] FIG. 1 shows an information acquisition system 1 according to an embodiment of the present disclosure. The information acquisition system 1 is composed of a substrate processing apparatus 2, an inspection wafer 6, and a computing device 8. First, an overview of each component of the information acquisition system 1 will be described. The substrate processing apparatus 2 performs processing by transporting a wafer W, which is a circular substrate, between processing modules using a transport mechanism. This processing includes supplying a resist to the wafer W stored in a cup in a processing module for forming a resist film, and forming the resist film.

[0010] The inspection wafer 6 is transported through the substrate processing apparatus 2 by the transport mechanism in place of the wafer W. Images of the annular protrusions and nozzles that make up the cup are then captured to obtain image data. The nozzles are used for EBR (Edge Bead Removal). EBR is a process in which a solvent is ejected from a nozzle to selectively remove a portion of a film (a resist film in this embodiment) that covers the peripheral edge of the wafer W, formed over the entire surface of the wafer W.

[0011] The computing device 8 acquires information on the distance between the wafer W and the annular protrusion when the wafer W is placed in the processing module, and the distance between the wafer W and the EBR nozzle, from the image data and data acquired in advance. By acquiring information on these distances before processing the wafer W by the substrate processing device 2, abnormalities in the processing when forming a resist film on the wafer W can be prevented.

[0012] The substrate processing apparatus 2 will be described in detail below. The substrate processing apparatus 2 is composed of a carrier block D1 and a processing block D2. The carrier block D1 and the processing block D2 are aligned on the left and right and connected to each other. Wafers W are stored in carriers C, which are transfer containers, and are transferred to the carrier block D1 by a transfer mechanism for the carriers C (not shown). The carrier block D1 is equipped with a stage 21 on which the carriers C are placed. The carrier block D1 is also equipped with an opening / closing unit 22 and a transfer mechanism 23. The opening / closing unit 22 opens and closes a transfer port formed in a sidewall of the carrier block D1. The transfer mechanism 23 transfers the wafers W to the carriers C on the stage 21 through the transfer port.

[0013] The processing block D2 includes a wafer W transfer path 24 extending in the left-right direction and a transfer mechanism 25 provided on the transfer path 24. The transfer mechanism 25 and the transfer mechanism 23 transfer wafers W between the carrier C and each processing module provided in the processing block D2. A plurality of processing modules are arranged side by side on both the front and rear sides of the transfer path 24. The processing module on the rear side is a heating module 26, which performs a heat treatment to remove solvent from the resist film. The processing module on the front side is a resist film forming module 3. A transfer module TRS on which wafers W are temporarily placed is provided at a position on the transfer path 24 near the carrier block D1. Wafers W are transferred between the carrier block D1 and the processing block D2 via the transfer module TRS.

[0014] Next, the resist film formation module 3 will be described with reference to the longitudinal side view of Fig. 2 and the plan view of Fig. 3. The resist film formation module 3 includes a spin chuck 31 serving as a substrate holder, which horizontally holds the wafer W by suction at the center of the backside of the wafer W. The spin chuck 31 is connected to a rotation mechanism 33 via a vertically extending shaft 32, and the rotation mechanism 33 rotates the wafer W held by the spin chuck 31 about the vertical axis. A shroud 34 is provided surrounding the shaft 32, and three lift pins 35 (only two are shown in Fig. 2) extend vertically and penetrate the shroud 34. The lift pins 35 are raised and lowered by a lift mechanism 36, and the wafer W is transferred between the spin chuck 31 and the transfer mechanism 25 described above.

[0015] A circular cup 4 is provided around the wafer W held by the spin chuck 31, extending from below the peripheral edge of the wafer W to the sides, and the cup 4 is made up of a cup body 41 and a guide portion 42. The cup body 41 is made up of an outer cylindrical portion 41A, an inclined portion 41B, a bottom body 41C, and an inner cylindrical portion 41D. The outer cylindrical portion 41A stands upright and is disposed outside the wafer W, and the upper edge of the outer cylindrical portion 41A extends obliquely upward toward the center of the cup 4, forming an inclined portion 41B. The inclined portion 41B surrounds the side periphery of the wafer W.

[0016] The lower end of outer cylindrical portion 41A extends toward the center of cup 4 to form bottom body 41C, and the inner peripheral edge of bottom body 41C extends upward to form inner cylindrical portion 41D. Inner cylindrical portion 41D is located closer to the outside of cup 4 than the peripheral edge of shroud 34. Outer cylindrical portion 41A, bottom body 41C, and inner cylindrical portion 41D formed in this manner form an annular recess that follows the circumference of wafer W, and this recess can receive processing liquid that drops or splashes from wafer W. Bottom body 41C is provided with exhaust pipe 43A for evacuating the inside of cup 4, and is also provided with exhaust port 43B for draining processing liquid from the recess.

[0017] Next, the guide portion 42, which is the lower member, will be described. The guide portion 42 is formed so as to widen from above the peripheral edge of the shroud 34 toward the outer cylindrical portion 41A, and is a member that forms a ring in a plan view, and is located below the wafer W held by the spin chuck 31. A lower annular protrusion 40 that contacts the inner peripheral surface of the inner cylindrical portion 41D is provided below the guide portion 42, so that no gap is formed between the inner cylindrical portion 41D and the guide portion 42, and the processing liquid does not leak out of the cup 4.

[0018] The upper surface of guide portion 42 is formed as inclined surfaces 44, 45, with inclined surface 44 located closer to the center of cup 4 than inclined surface 45. Inclined surface 44 rises toward the outside of cup 4, and inclined surface 45 descends toward the outside of cup 4, so that the longitudinal cross section of guide portion 42 is formed in a mountain shape. The periphery of guide portion 42 is located away from the inner circumferential surface of outer cylindrical portion 41A and protrudes downward, forming vertical portion 46. This vertical portion 46 and inclined surface 45 serve to guide the processing liquid (resist and solvent) that has fallen or scattered from wafer W and adheres to it so that it flows downward toward bottom body 41C.

[0019] The inclined surface 44 has a steeper slope at the peripheral edge thereof near the outside of the cup 4, and the inclined surface 45 has a steeper slope at the peripheral edge thereof near the center of the cup 4, thereby forming an annular protrusion 47. That is, the annular protrusion 47 protrudes upward and follows the periphery of the wafer W placed on the spin chuck 31, and is close to the peripheral edge of the wafer W. The annular protrusion 47 prevents the processing liquid supplied to the front surface of the wafer W from flowing around to the back surface of the wafer W and depositing at a position near the center of the wafer W, and prevents mist of the processing liquid from depositing at a position near the back surface of the wafer W. For example, as shown in FIG. 4, the height at which the guide portion 42 is attached relative to the cup body 41 is adjustable. Therefore, the height of the annular protrusion 47 relative to the wafer W and the spin chuck 31 supporting the wafer W is adjustable. The distance between the back surface of the wafer W and the upper end of the annular protrusion 47 is indicated as a cup clearance distance H0 in FIG. 4.

[0020] Next, the resist supply mechanism 5A and EBR processing mechanism 5B provided in the resist film forming module 3 will be described. The resist supply mechanism 5A includes a resist supply nozzle 51A, a resist supply unit 52A, an arm 53A, a moving mechanism 54A, and a waiting unit 55A. The resist supply nozzle 51A discharges resist pressure-fed from the resist supply unit 52A vertically downward. The arm 53A supports the resist supply nozzle 51A and is configured to be freely raised and lowered and moved horizontally by the moving mechanism 54A. A waiting unit 55A with an upward opening is provided outside the cup 4, and the resist supply nozzle 51A is moved between the opening of the waiting unit 55A and the inside of the cup 4 by the moving mechanism 54A. Once inside the cup 4, the resist supply nozzle 51A discharges resist onto the center of the rotating wafer W, forming a resist film over the entire surface of the wafer W by spin coating.

[0021] The EBR processing mechanism 5B includes a solvent supply nozzle 51B, a solvent supply unit 52B, an arm 53B, a moving mechanism 54B, and a standby unit 55B. The solvent supply nozzle 51B is a nozzle for EBR, and discharges the solvent pressure-fed from the solvent supply unit 52B diagonally downward from the center of the wafer W toward the peripheral edge. In other words, the solvent is discharged in a direction tilted relative to the vertical. The arm 53B supports the solvent supply nozzle 51B and is configured to be freely raised and lowered and moved horizontally by the moving mechanism 54B. A standby unit 55B with an upward opening is provided outside the cup 4. The moving mechanism 54B moves the solvent supply nozzle 51B between the opening of the standby unit 55B and a processing position above the wafer W in the cup 4. Note that FIG. 3 shows the solvent supply nozzle 51B in the processing position with a solid line. The previously described EBR is performed by discharging the solvent from the solvent supply nozzle 51B at the processing position onto the rotating wafer W.

[0022] For example, the height of the solvent supply nozzle 51B is adjustable relative to the arm 53B. Therefore, the distance H1 (referred to as the nozzle separation distance) between the solvent supply nozzle 51B and the surface of the wafer W at the processing position shown in FIG. 4 is adjustable, and changing the nozzle separation distance H1 changes the landing position on the wafer W of the solvent discharged from the solvent supply nozzle 51B. Although shown only in FIG. 3, an illumination unit 48 capable of irradiating light toward the cup 4 is provided near the cup 4. When an image of the solvent supply nozzle 51B is captured, as will be described later, the illumination unit 48 irradiates the solvent supply nozzle 51B with light.

[0023] The substrate processing apparatus 2 includes a control unit 20 configured by a computer (see FIG. 1), into which a program stored in a storage medium such as a compact disc, a hard disk, a memory card, or a DVD is installed. The installed program contains instructions (steps) so that control signals are output to each unit of the substrate processing apparatus 2. These control signals then cause the transfer mechanisms 23 and 25 to transfer the wafer W, and each processing module to process the wafer W.

[0024] However, due to an error made by an operator when assembling or adjusting the resist film formation module 3, the first distance, the cup separation distance H0, and / or the second distance, the nozzle separation distance H1, may fall outside the appropriate range. If the wafer W is processed with the cup separation distance H0 inappropriate, the annular protrusion 47 may come into contact with the wafer W and damage the backside of the wafer W, or the annular protrusion 47 may be too far away from the wafer W and fail to fully perform its function. Furthermore, if the wafer W is processed with the nozzle separation distance H1 inappropriate, the width of the area from which the resist film is removed may be abnormal. To prevent these problems from occurring, the information acquisition system 1 acquires image data of the annular protrusion 47 and the solvent supply nozzle 51B, as described above, and acquires the cup separation distance H0 and the nozzle separation distance H1 as distance information from the image data.

[0025] The configuration of the inspection wafer 6, which is an information acquisition body used to acquire image data, will be described below with reference to the side view of FIG. 5 and the plan view of FIG. 6. The inspection wafer 6 includes a main body 60, a first camera 61, a second camera 62, a mirror 64, an illumination unit 65, an equipment mounting board 71, and a battery 72. The main body 60 is a circular substrate the same size as the wafer W in a plan view, and the first camera 61, the second camera 62, the mirror 64, the illumination unit 65, the equipment mounting board 71, and the battery 72 are mounted on the main body 60. The main body 60 is transported by the transport mechanisms 23 and 25 and the module lift pins 35, just like the wafer W. The underside of the main body 60 is flat, just like the underside of the wafer W, so that the central portion of the backside is held by suction on the spin chuck 31. FIGS. 5 and 6 show the inspection wafer 6 held by the spin chuck 31 in this state.

[0026] Through holes 66A and 66B are formed at the periphery of the main body 60 at positions spaced apart in the circumferential direction of the main body 60. Upstanding substrates 67A and 67B are attached to the periphery of the through holes 66A and 66B at positions closer to the center of the main body 60 within the through holes 66A and 66B. The substrates 67A and 67B protrude above the through holes 66A and 66B, respectively. A first camera 61 and a second camera 62 are mounted on the substrates 67A and 67B so as to be able to capture images of the main body 60, respectively. The fields of view of the first camera 61 and the second camera 62, which are the imaging units, are directed toward the periphery of the main body 60.

[0027] A mirror 64 is disposed on the optical axis of the first camera 61, and the mirror 64 captures an image of the area below the main body 60 via the through-hole 66A. Therefore, the first camera 61 can capture an image of the area below the main body 60 via the through-hole 66A and the mirror 64. When the inspection wafer 6 is held by the spin chuck 31, the mirror 64 is positioned above the annular protrusion 47, and the first camera 61 can capture an image of a portion of the upper surface of the annular protrusion 47 in the circumferential direction. FIG. 7 schematically shows an example of image data acquired by this imaging, and the frame surrounded by a dotted line in the figure represents one pixel.

[0028] Two lighting units 65 are embedded in the main body 60. The lighting units 65 are positioned on either side of the through-hole 66A in the circumferential direction of the main body 60 and irradiate light downward. When an image is captured by the first camera 61, light is irradiated from each lighting unit 65 onto an object below. The first camera 61, the second camera 62, and the mirror 64 are located closer to the center of the main body 60 than the solvent supply nozzle 51B so as not to interfere with the solvent supply nozzle 51B when the inspection wafer 6 is rotated to capture an image of the solvent supply nozzle 51B at the processing position, as described below.

[0029] A device mounting board 71 is provided in the center of the main body 60. The boards 67A and 67B are connected to the device mounting board 71 via cables (not shown), and image data acquired by the first camera 61 and the second camera 62 is transmitted to the device mounting board 71 via these boards 67A and 67B and the cables. The device mounting board 71 is composed of multiple boards, including a DSP (digital signal processor) board, but is shown as a single board for convenience, and has various devices mounted thereon. These devices include a device that captures images using the first camera 61 and the second camera 62 by wirelessly receiving a signal from the arithmetic unit 8, a device that switches on and off light irradiation by the illumination unit 68, and a device (transmitter) that wirelessly transmits acquired image data to the arithmetic unit 8. A battery 72 is provided in the center of the main body 60 and supplies power to the first camera 61, the second camera 62, the devices included in the device mounting board 71, and the illumination unit 68.

[0030] Next, the arithmetic unit 8 will be described with reference to Fig. 5. The arithmetic unit 8 is a computer and includes a bus 81. A program storage unit 82, a wireless transmission / reception unit 83, a memory 84, a display unit 85, and an operation unit 86 are connected to the bus 81. A program 80 stored on a storage medium such as a compact disc, a hard disk, a memory card, or a DVD is installed in the program storage unit 82.

[0031] The wireless transceiver 83 is a device for wirelessly transmitting a signal that serves as a trigger for acquiring image data to the inspection wafer 6 and for wirelessly receiving the acquired image data. The memory 84, which serves as the first and second storage units, stores the acquired image data and advance preparation data, which will be described in detail later. The display unit 85 is a display that displays the acquired cup separation distance H0 and nozzle separation distance H1. The operation unit 86 is composed of a mouse, keyboard, etc., and the user of the information acquisition system 1 can use the operation unit 86 to instruct the execution of processes that can be performed by the program 80, such as sending the trigger signal described above.

[0032] Furthermore, for example, the arithmetic device 8 is connected to the control unit 20 of the substrate processing apparatus 2, and can transmit and receive data and signals necessary to acquire the cup separation distance H0 and the nozzle separation distance H1. For example, when the inspection wafer 6 is placed on the spin chuck 31, the control unit 20 transmits a signal to the arithmetic device 8 indicating that image data can be acquired.

[0033] A supplementary explanation will be given for the program 80 of the computing device 8. The program 80 is structured so as to transmit and receive the aforementioned data and signals, store image data in memory 84, acquire the cup separation distance H0 and nozzle separation distance H1 based on the image data and advance preparation data, and display the acquired cup separation distance H0 and nozzle separation distance H1 on a display unit 85. Therefore, the program 80 constitutes an acquisition unit that acquires the distance (height) between the wafer W and the object to be imaged by the camera. The program 80 also identifies predetermined pixels in the image data for acquiring the cup separation distance H0 and nozzle separation distance H1, detects the number of pixels in a predetermined area, and performs various calculations, as will be described later.

[0034] Next, the preparation data stored in the memory 84 of the calculation device 8 as described above will be explained, along with a method for obtaining the cup separation distance H0 and the nozzle separation distance H1 from the preparation data. The preparation data includes data for obtaining the cup separation distance H0 and data for obtaining the nozzle separation distance H1, and first the data for obtaining the cup separation distance H0 will be explained with reference to FIG. 8.

[0035] Outside the substrate processing apparatus 2, a jig 91 is placed below the inspection wafer 6 in an area where imaging by the first camera 61 is possible. There are no restrictions on the shape of the jig 91, but it may be, for example, a thin, elongated member that extends horizontally (in the direction from the front to the back of the paper in FIG. 8 ) similar to the annular protrusion 47. The width L1 of the upper end face of this jig 91 is known, for example, 1 mm. The separation distance between the jig 91 and the lower face of the main body 60 of the inspection wafer 6 is set to H2 (unit: mm). This separation distance H2 is changed, and each time it is changed, the jig 91 is imaged and image data is obtained. In other words, multiple image data for the jig 91 are obtained. Imaging

[0036] The number of pixels in the width of the upper end surface of the jig 91 in each image data is then obtained, and the correspondence between the number of pixels and the separation distance H2 is determined from the obtained results, as shown in the graph in FIG. 9. In this graph, the X-axis represents the number of pixels on the upper end surface of the jig 91, and the Y-axis represents the separation distance H2, with each point on the graph representing the obtained results. From each point, an approximation of a linear function, for example, Y=AX+B (A and B are constants) is obtained. This approximation represents the change in the number of pixels on the upper end surface of the jig 91 relative to the change in separation distance H2, and is shown as a straight line 92 in the figure. The width L2 of the upper end of the annular protrusion 47 (see FIG. 4) is also obtained. The approximation Y=AX+B and the width L2 are preliminary data for obtaining the cup separation distance H0.

[0037] The procedure for acquiring the cup separation distance H0 from the above-mentioned advance preparation data will be described. When the first camera 61 acquires image data of the annular protrusion 47 shown in FIG. 7 with the inspection wafer 6 held on the spin chuck 31 as shown in FIGS. 5 and 6, pixels at one end and the other end of the width L3 of the annular protrusion 47 in the image data are identified. Then, the number of pixels from the pixel at one end to the pixel at the other end is detected. That is, the number of pixels in the width L3 of the annular protrusion 47 in the image data is detected (step S1). In the example of the image shown in FIG. 7, the number of pixels is 14. Then, in the approximation formula Y=AX+B described above, the number of pixels in the width L3 is used as the value of X, thereby calculating the value of Y in the approximation formula (step S2).

[0038] As described above, this approximation formula was obtained using the jig 91 with a width L1 of 1 mm. Therefore, the value of Y calculated in this manner corresponds to the separation distance H2 between the annular protrusion 47 and the test wafer 6 when the width L2 of the annular protrusion 47 is 1 mm. The underside of the wafer W and the underside of the main body 60 of the test wafer 6 are both flat, and the heights of the underside of the main body 60 and the underside of the wafer W are the same when held by the spin chuck 31. Therefore, the value of Y is also the distance between the annular protrusion 47 and the underside of the wafer W when the width L2 is 1 mm (=cup separation distance H0). Therefore, Y is corrected to correspond to the actual width L2 of the annular protrusion 47 by multiplying it by the width L2 of the annular protrusion 47, and the multiplied value (=Y×L2) is determined as the cup separation distance H0 (step S3). The cup separation distance H0 calculated in this manner is displayed on the display unit 85 of the computing device 8 (step S4). Steps S1 to S4 described above are performed by the program 80. The above approximate formula Y=AX+B is correlation data that represents the correlation between the number of pixels in the width of the annular protrusion 47 when the width of the annular protrusion 47 is 1 mm and the distance between the wafer W and the annular protrusion 47. L2, which is multiplied by Y as described above, corresponds to correction data that corrects this correlation data.

[0039] Next, the preparation data for acquiring the nozzle separation distance H1 will be described with reference to FIGS. 10 and 11. The image acquired by the second camera 62 is assumed to be a VGA image, i.e., 640 pixels horizontally and 480 pixels vertically. As shown in FIG. 10, a jig 93 is placed adjacent to the side of the inspection wafer 6, and the second camera 62 captures an image of the jig 93 to acquire image data. The shape of the jig 93 is not limited, but it may be, for example, a rod-shaped member extending vertically. The relative height between the jig 93 and the inspection wafer 6 is changed so that the top end of the jig 93 is positioned at a reference height H3, which is the vertical center of the image, i.e., so that it appears at the 240th pixel counting from the bottom of the image. In other words, the top end of the jig 93 is aligned with the reference height. FIG. 11 schematically illustrates the image acquired by the second camera 62 when changing the relative height. In the example shown in Figure 10, when the jig 93 is raised relative to the inspection wafer 6 and the jig 93 is positioned at the position shown by the dotted line in Figure 10, the upper end of the jig 93 is shown to be positioned at the reference height H3 in the image, as shown in the lower part of Figure 11.

[0040] Once the upper end of the jig 93 is positioned at the reference height H3, a height H4 between the upper end of the jig 93 and the underside of the test wafer 6 is obtained. The method for obtaining this fourth distance, height H4, is arbitrary; for example, a tool such as a caliper may be used to measure the distance between the upper end of the jig 93 and a position on the jig 93 at the same height as the underside of the test wafer 6. In the above example, the upper end of the jig 93 is aligned with the reference height H3. Alternatively, a marking may be provided on the side of the jig 93, the marking may be aligned with the reference height H3, and the distance between the marking and the underside of the test wafer 6 may be measured to obtain height H4. In this way, height H4 can be obtained by aligning any position on the jig 93 with the reference height H3.

[0041] The thickness of the wafer W is subtracted from the height H4 thus obtained to obtain a height H5. As described above, the height of the underside of the wafer W placed on the spin chuck 31 is the same as that of the underside of the inspection wafer 6 placed on the spin chuck 31. Therefore, this height H5 is the height difference between the surface of the wafer W placed on the spin chuck 31 and the actual height position of the inspection wafer 6 placed on the spin chuck 31, which corresponds to the height shown as the reference height H3 in the image acquired by the second camera 62 (see FIG. 10). This H5, which is the third distance, is defined as the wafer reference height. In addition, the width L4 of the solvent supply nozzle 51B (see FIG. 4) is acquired. This width L4 is conversion information used to convert the number of pixels in the image data into an actual distance, as will be described later. The wafer reference height H5 and the width L4 of the solvent supply nozzle 51B are pre-prepared data for acquiring the nozzle separation distance H1.

[0042] The procedure for acquiring the nozzle separation distance H1 from the above-mentioned advance preparation data will now be described. With the inspection wafer 6 held on the spin chuck 31 as shown in FIGS. 5 and 6, the second camera 62 acquires image data of the side surface of the solvent supply nozzle 51B as shown in FIG. 12. The bottom end of the solvent supply nozzle 51B is identified in this image data. The number of pixels corresponding to the width L4 of the solvent supply nozzle 51B is also detected in the image data (Step T1). More specifically, the detection of the number of pixels corresponding to the width L4 involves identifying a pixel at one end of the width direction of the solvent supply nozzle 51B (referred to as the first pixel) and a pixel at the other end (referred to as the second pixel), and detecting the number of pixels between these first and second pixels. Specifically, if the first pixel and the second pixel are separated by, for example, three pixels vertically and four pixels horizontally, the number of pixels corresponding to the width L4 is (3 2 +4 2 ) 1 / 2 = 5 pixels.

[0043] Next, in the image data, the number of pixels at a height H6 between the bottom end of the solvent supply nozzle 51B identified in step T1 and the reference height H3 (i.e., the pixels at a height preset in the image data) is detected (step T2). This H6 is set as the nozzle reference height. Then, a calculation is performed on the width L4 of the solvent supply nozzle 51B (preparation data) divided by the number of pixels corresponding to the width L4 acquired in step T1, and this calculated value is set as the distance per pixel (step T3). Then, the number of pixels at the nozzle reference height H6 calculated in step T2 is multiplied by the distance per pixel calculated in step T3. In other words, the nozzle reference height H6, which is the number of pixels in the image data, is converted to an actual height (distance) (step T4).

[0044] When the lower end of the solvent supply nozzle 51B is located below the reference height H3 in the image data, the calculation is performed by subtracting the actual nozzle reference height H6 obtained in step T4 from the wafer reference height H5 (preparatory data). Also, when the lower end of the solvent supply nozzle 51B is located above the reference height H3 in the image data, as shown in FIG. 12, the calculation is performed by subtracting or adding the wafer reference height H5 (preparatory data) from the actual nozzle reference height H6 obtained in step T4. The calculated value obtained by subtracting or adding H6 from H5 is determined as the nozzle separation distance H1 (step T5) and displayed on the display unit 85 of the computing device 8 (step T6). Steps T1 to T6 are performed by the program 80.

[0045] As described above, the height H5 between the surface of the wafer W and the reference height H3 of the image is acquired as advance preparation data. Then, by capturing an image of the solvent supply nozzle 51B, the height H6 between the bottom end of the nozzle 51 and the reference height H3 of the image is acquired, and H6 is added to or subtracted from H5. In other words, the nozzle separation distance H1 between the surface of the wafer W and the bottom end of the solvent supply nozzle 51B is calculated in stages by dividing the distance based on the reference height H3. The nozzle separation distance H1 is calculated in this manner because the field of view of the second camera 62 is limited.

[0046] The reason for calculating the nozzle separation distance H1 as described above will be described in detail below. Let us assume that the second camera 62 can capture images of the solvent supply nozzle 51B and a position directly below the solvent supply nozzle 51B on the main body 60 of the inspection wafer 6. In this case, the height between the main body 60 and the solvent supply nozzle 51B is calculated from the number of pixels between the position directly below and the solvent supply nozzle 51B and the distance per pixel calculated in step T3 above, and the nozzle separation distance H1 can be calculated by taking into account the difference in thickness between the wafer W and the main body 60.

[0047] However, because the inspection wafer 6 is transported by the transport mechanisms 23 and 25, the second camera 62 is disposed on the main body 60 of the inspection wafer 6, as described above. This placement constraint limits the field of view of the second camera 62, and it may not be possible to capture the position directly below the solvent supply nozzle 51B on the main body 60. Therefore, as described above, the nozzle separation distance H1 is calculated in stages by dividing the reference height H3 into heights H5 and H6. This method therefore has the advantage of enabling the inspection wafer 6 to be transported by the transport mechanisms 23 and 25 while accurately calculating the nozzle separation distance H1. Note that although the vertical center of the image is set as the reference height H3, any height other than the center may be set as the reference height. For example, the reference height may be set to a height that is ¼ of the entire image from the bottom edge of the image (i.e., 120 pixels from the bottom edge). Furthermore, in step T1, the number of pixels for the width L4 of the solvent supply nozzle is obtained, but this number of pixels does not necessarily have to be obtained each time the nozzle separation distance H1 is calculated, and may be stored in the memory 84 of the calculation device 8 as a fixed value, for example.

[0048] The following describes the operating procedure of the information acquisition system 1 described above. First, as a preparation step, images of the jigs 91 and 93 described in Figures 8 and 10 are taken, and the approximation formula and wafer reference height H5 described in Figure 9 are obtained. In addition to these approximation formulas and wafer reference height H5, the width L2 of the annular protrusion 47 and the width L4 of the solvent supply nozzle 51B are stored in the memory 84 of the computing device 8 as advance preparation data.

[0049] After the above preparation steps are completed, the carrier C storing the inspection wafer 6 is transported to the stage 21 of the substrate processing apparatus 2. The inspection wafer 6 is transported in the order of the transport mechanism 23 → transfer module TRS → transport mechanism 25 → resist film forming module 3, and is placed on the spin chuck 31 via the lift pins 35 and is adsorbed and held thereon. Thereafter, the solvent supply nozzle 51B moves from the standby section 55B to the processing position.

[0050] When the user issues a predetermined instruction from the arithmetic unit 8, the spin chuck 31 rotates intermittently, for example, at predetermined angular intervals, and when the rotation stops, the second camera 62 captures an image to acquire image data. The acquired image data is sequentially transmitted wirelessly to the arithmetic unit 8. When image data of the entire circumference of the peripheral portion of the inspection wafer 6 has been acquired, the intermittent rotation and the capture of images by the second camera 62 stop, and the solvent supply nozzle 51B returns to the standby section 55B. Then, the first camera 61 captures an image of the top surface of the annular protrusion 47, and the image data shown in FIG. 7 is transmitted wirelessly to the arithmetic unit 8.

[0051] The above-described steps S1 to S4 are performed on the image data acquired by the first camera 61, and the cup separation distance H0 is calculated and displayed on the screen of the display unit 85 of the arithmetic device 8. Furthermore, from the plurality of image data acquired by the second camera 62, for example, the image that shows the solvent supply nozzle 51B as shown in FIG. 12 is selected by the program 80 of the arithmetic device 8. Then, the above-described steps T1 to T6 are performed on the selected image data, and the nozzle separation distance H1 is calculated and displayed on the screen of the display unit 85 of the arithmetic device 8.

[0052] After the imaging, the inspection wafer 6 is transferred to the transport mechanism 25 via the lift pins 35 and loaded into another resist film forming module 3. The inspection wafer 6 is then imaged in the same manner as when it was loaded into the previous resist film forming module 3. The cup separation distance H0 and nozzle separation distance H1 are then calculated for the relevant resist film forming module 3 and displayed on the screen. Once the cup separation distance H0 and nozzle separation distance H1 have been acquired for all resist film forming modules 3, the inspection wafer 6 is returned to the carrier C via the transport mechanism 25, the transfer module TRS, and the transport mechanism 23 in that order. The operator looks at the cup separation distance H0 and nozzle separation distance H1 displayed on the screen for each resist film forming module 3 and adjusts the height of the guide portion 42 of the cup 4 equipped with the annular protrusion 47 or the solvent supply nozzle 51B in the resist film forming module 3 that is deemed to require adjustment.

[0053] Thereafter, the carrier C storing the wafer W is transferred to the stage 21 of the substrate processing apparatus 2. The wafer W is transferred in the following order: transfer mechanism 23 → transfer module TRS → transfer mechanism 25 → resist film forming module 3 → transfer mechanism 25 → heating module 26 → transfer mechanism 25 → transfer module TRS, and then returned to the carrier C by the transfer mechanism 23. In the resist film forming module 3, resist is discharged from the resist supply nozzle 51A onto the center of the surface of the wafer W rotated by the spin chuck 31. The resist spreads toward the peripheral edge of the wafer W, forming a resist film over the entire surface of the wafer W. Thereafter, the solvent supply nozzle 51B moves from the standby section 55B to the processing position, where a solvent is supplied to the peripheral edge of the rotating wafer W, thereby removing the resist film from the peripheral edge.

[0054] In this way, the information acquisition system 1 acquires the cup separation distance H0 and the nozzle separation distance H1, and an operator can adjust the resist film formation module 3 based on the acquired data. This prevents defective processing of the wafer W in the resist film formation module 3. As a result, it is possible to prevent a decrease in the yield of semiconductor products manufactured from the wafer W. Note that, although the operating procedure of the above system involves performing the preparation process to acquire advance preparation data before acquiring image data, the preparation process may be performed after acquiring image data.

[0055] 13 shows another example of the configuration of cup 4. In this cup 4, the upper end of support 38 is connected to the lower part of guide portion 42 having an annular protrusion 47. The lower end of support 38 penetrates bottom portion 41C of cup body 41 and is connected to lifting mechanism 39, which is a first lifting mechanism, and this lifting mechanism 39 can raise and lower guide portion 42. Even when guide portion 42 is raised and lowered in this manner, no gap is formed between inner cylindrical portion 41D of cup body 41 and guide portion 42 due to lower annular protrusion 40 of guide portion 42, and the processing liquid and its mist in cup 4 do not leak out of cup 4.

[0056] If the acquired cup separation distance H0 is outside the allowable range, for example, a control signal is output by the control unit 20, and the height of the guide part 42 is adjusted by the lifting mechanism 39 so that the cup separation distance H0 falls within the allowable range. In other words, the relative height between the spin chuck 31 and the annular protrusion 47 is changed according to the cup separation distance H0.

[0057] Furthermore, if the acquired nozzle separation distance H1 is outside the allowable range, for example, the control unit 20 may output a control signal, and the movement mechanism 54B may adjust the height of the solvent supply nozzle 51B at the processing position so that it falls within the allowable range (see FIG. 13). In other words, the movement mechanism 54B is a second lifting mechanism that changes the relative height between the solvent supply nozzle 51B and the spin chuck 31 in accordance with the nozzle separation distance H1. Note that, to ensure that the cup separation distance H0 and the nozzle separation distance H1 each fall within the allowable range, the lifting mechanism 39 and the movement mechanism 54B are configured to be able to change the height of the guide unit 42 and the solvent supply nozzle 51B in multiple stages.

[0058] This automatic adjustment of the cup separation distance H0 and the nozzle separation distance H1 eliminates the need for an operator to adjust the heights of the guide unit 42 and the solvent supply nozzle 51B. This prevents the need to stop processing of wafers W in the substrate processing apparatus 2 to perform the height adjustments, thereby improving the productivity of the substrate processing apparatus 2. When the cup separation distance H0 and the nozzle separation distance H1 are automatically adjusted, the cup separation distance H0 and the nozzle separation distance H1 do not need to be displayed on the display unit 85. Therefore, a system configuration without the display unit 85 may be used. Alternatively, the rotation mechanism 33 connected to the spin chuck 31 may be connected to an elevation mechanism, and the spin chuck 31 and the rotation mechanism 33 may be elevated and elevated relative to the cup 4 and the solvent supply nozzle 51B to adjust the cup separation distance H0 and the nozzle separation distance H1.

[0059] For ease of explanation, the cup 4 in one resist film forming module 3 in the substrate processing apparatus 2 is referred to as 4A, and the cup 4 in the other resist film forming module 3 is referred to as 4B. The cups 4A and 4B are configured so that the width L2 of the upper surface of each annular protrusion 47 is different from each other. In this case, the width L2 of cup 4A and the width L2 of cup 4B are stored in the memory 84 of the calculation device 8 as advance preparation data, and calculations are performed using L2 corresponding to the cup 4 for which the cup separation distance H0 is to be obtained. In other words, the width L2 as advance preparation data may be stored for each cup 4, and may be selected according to the cup 4 for which the cup separation distance H0 is to be obtained, to perform the above-described calculations.

[0060] The selection of the width L2, which is the correction data used in this calculation, may be performed by an operator using the calculation device 8. Alternatively, for example, the correspondence between the resist film forming modules 3 and the width L2 in each module may be stored in the memory 84 of the calculation device 8. When the test wafer 6 is transferred to one of the multiple resist film forming modules 3, information about that resist film forming module 3 is sent from the control unit 20 of the substrate processing apparatus 2 to the calculation device 8, and the program 80 of the calculation device 8 may select the width L2 corresponding to that resist film forming module 3 in accordance with the information, and calculate the cup separation distance H0. In other words, the width L2 of the cup 4 of the resist film forming module 3 may be automatically selected depending on the resist film forming module 3 to which the test wafer 6 is transferred.

[0061] In the above example, only one circumferential location of the annular protrusion 47 is imaged and the cup separation distance H0 is calculated. However, multiple circumferential locations may be imaged by the first camera 61, and the cup separation distance H0 may be calculated from each image data. By acquiring the cup separation distance H0 at multiple locations in this manner, an abnormality such as the guide portion 42 being installed at an angle can be detected. That is, if the circumferential location of the annular protrusion 47 is within the allowable range at some locations but not at other locations, this can be detected as an abnormality. When imaging is performed multiple times by the first camera 61, imaging may be performed simultaneously with imaging by the second camera 62, for example. That is, the inspection wafer 6 may be rotated intermittently, and when imaging by the second camera 62 is performed while the rotation is stopped, imaging by the first camera 61 may also be performed.

[0062] In the information acquisition system 1 described above, the control unit 20 and the arithmetic device 8 are provided separately. However, the control unit 20 may also serve as the arithmetic device 8. Furthermore, while the image data is wirelessly transmitted to the arithmetic device 8 in the example described above, the image data may be stored in a removable memory mounted on the main body of the inspection wafer 6. In this case, after imaging, an operator removes the memory from the inspection wafer 6 returned to the carrier C and transfers the image data to the arithmetic device 8, thereby acquiring the cup separation distance H0 and the nozzle separation distance H1. Therefore, the inspection wafer 6 does not need to be configured to wirelessly transmit image data. Alternatively, the inspection wafer 6 and the arithmetic device 8 may be connected by a wire, and the image data may be transmitted to the arithmetic device 8. However, because components such as cables connecting them may interfere with the transport of the inspection wafer 6, it is more advantageous to wirelessly transmit the image data or store it in a memory mounted on the inspection wafer 6, as described above.

[0063] Furthermore, only one of the first camera 61 and the second camera 62 may be mounted on the main body 60, and image data may be acquired using only one of the annular protrusion 47 and the solvent supply nozzle 51B as the imaged object, thereby acquiring only one of the cup separation distance H0 and the nozzle separation distance H1. The object imaged by the first camera 61 is not limited to the annular protrusion 47. For example, the upper surface of the guide portion 42 may be a flat surface, and a nozzle may be provided on the flat surface as an upward protrusion. The nozzle discharges a cleaning liquid toward the peripheral portion of the underside of the wafer W. The first camera 61 may capture an image of the nozzle, and the separation distance between the nozzle and the underside of the wafer W may be acquired using the method described above. Furthermore, the processing liquid supplied from the nozzle to the peripheral portion of the wafer W is not limited to a solvent and may be, for example, a coating liquid for forming a coating film. The height between the nozzle and the surface of the wafer W can be calculated using the method described above.

[0064] The following provides additional information regarding the placement of the second camera 62 on the inspection wafer 6. Images captured by cameras typically suffer from distortion, with the peripheral portion being more distorted than the central portion. Therefore, if the lower end of the solvent supply nozzle 51B is positioned at the upper or lower end of the image captured by the second camera 62, an error may occur in the calculated nozzle separation distance H1 relative to the actual distance. To minimize this error, the second camera 62 is mounted on the main body 60 of the inspection wafer 6 so that the lower end of the solvent supply nozzle 51B positioned at the center of the image height when the solvent supply nozzle 51B is moved to the predetermined processing position. Therefore, in the image illustrated in FIG. 12, if the solvent supply nozzle 51B is positioned at the normal height, the upper end of the arrow H6 is positioned at the center of the image height. If the height of the captured image is X pixels, the center of the image height is, for example, a height shifted X / 10 pixels upward from the center of the image height to a height shifted X / 10 pixels downward from the center of the image height.

[0065] To capture the solvent supply nozzle 51B in the image, the second camera 62 may be positioned so that its lower portion enters a through-hole 66B formed in the main body 60, as shown in FIG. 5, or may be mounted on a platform provided on the main body 60. That is, a height adjustment unit, such as a through-hole or platform, may be provided to change the height between the surface (top surface) of the main body 60 and the lower end of the second camera 62. Furthermore, to facilitate adjusting the height of the solvent supply nozzle 51B in the image, the height of the second camera 62 on the main body 60 may be configured to be adjustable. To cite a specific example, in the above-described example, the second camera 62 is mounted on a vertically oriented board 67B. However, a bar screw protrudes from the main body 60 and a nut is threaded onto the board 67B, and the board 67B is positioned horizontally on the nut. The second camera 62 is placed on the board 67B, and an operator can turn the nut to change its height, thereby changing the height of the second camera 62 along with the board 67B.

[0066] Alternatively, the substrate 67B may be connected to the main body 60 via a slide rail extending vertically, allowing an operator to adjust the height of the substrate 67B relative to the main body 60. A height adjustment unit, such as a screw, nut, or slide rail, may be provided to change the height of the second camera 62 relative to the main body 60. Note that, when the lower end of the solvent supply nozzle 51B is not positioned at the center of the image height, as described above, in the image acquired by the second camera 62, it may be determined that the height of the solvent supply nozzle 51B is abnormal without acquiring the nozzle separation distance H1.

[0067] Although the second camera 62 is configured to capture an image of the solvent supply nozzle 51B, it may also be configured to capture an image of the resist supply nozzle 51A, thereby acquiring the distance between the resist supply nozzle 51A and the surface of the wafer W. The liquid processing module installed in the substrate processing apparatus 2 is not limited to the resist film formation module 3. It may be a module that supplies a processing liquid for forming a coating film other than a resist film, such as an anti-reflection film or an insulating film, from a nozzle onto the surface of the wafer W to form a film, or a module that supplies a cleaning liquid, a developer, or an adhesive for bonding multiple wafers W to the surface of the wafer W from a nozzle onto the surface of the wafer W. The distance between the nozzle that supplies a processing liquid other than a resist and the surface of the wafer W can also be acquired using the present technology. The inspection wafer 6 is not necessarily transported from the outside to the substrate processing apparatus 2 by the carrier C. For example, a module for storing the inspection wafer 6 may be installed within the substrate processing apparatus 2, and the inspection wafer 6 may be transported between the module and the resist film formation module 3.

[0068] Second Embodiment Next, an example of an inspection using an inspection wafer 6 according to the second embodiment will be described. To this end, the configuration of the cup 4 of the resist film forming module 3 will first be described in more detail with reference to the vertical cross-sectional side view of FIG. 14. The cup 4 includes an intermediate guide portion 101 and an upper guide portion 111. Note that in FIG. 2, the intermediate guide portion 101 is shown simply as an inclined portion 41B, and the upper guide portion 111 is omitted.

[0069] The intermediate guide portion 101 includes a vertical wall 102 attached to the inner peripheral surface of the outer cylindrical portion 41A that constitutes the cup 4, and an inclined wall 103 that extends obliquely upward from the upper end of the vertical wall 102 toward the center of the cup 4. The inclined wall 103 is configured in a circular ring shape in a plan view. The inclined wall 103 is provided with a through-hole 104 in the vertical direction for discharging liquid.

[0070] The upper guide part 111 includes an upper vertical wall 112 attached to the inner peripheral surface of the outer cylindrical part 41A, an upper wall 113 extending generally horizontally from the upper end of the upper vertical wall 112 toward the center of the cup 4, and a cylindrical opening wall 114 extending vertically upward from the tip of the upper wall 113. The upper vertical wall 112 is provided above the vertical wall 102 of the intermediate guide part 101, and the upper wall 113 is located above the inclined wall 103 of the intermediate guide part 101.

[0071] As configured as described above, the side wall of the cup 4 is made up of the outer cylindrical portion 41A, the vertical wall 102 of the intermediate guide portion 101, and the upper vertical wall 112. An inclined wall 103 protrudes from a position lower than the upper end of the side wall, and an upper wall 113 protrudes from the upper end of the side wall toward the center of the cup 4. The inclined wall 103 and the upper wall 113 form an annular protrusion protruding from the side wall in this manner, and form a circular ring that is coaxial with the central axis of the spin chuck 31 in a plan view and surrounds the wafer W placed on the spin chuck 31.

[0072] The upper guide portion 111, which is the upper annular body, and the intermediate guide portion 101, which is the intermediate annular body, may be attached to the outer cylindrical portion 41A of the cup 4 at an abnormal height due to an error during assembly or adjustment of the cup 4. This abnormal height may occur when the upper guide portion 111 is attached to the cup body 41 at an angle, resulting in an abnormal height in only a portion of the circumferential direction. In such an abnormal height state, the desired exhaust performance may not be achieved in each portion of the cup 4, resulting in poor processing of the wafer W, or mist of the processing liquid may be scattered outside the cup 4. Furthermore, if the height of the upper guide portion 44 is abnormal, it may interfere with the nozzles passing over the cup 4.

[0073] In the second embodiment, image data acquired by the second camera 62 on the inspection wafer 6 is used to acquire information about the heights of the solvent supply nozzle 51B, the intermediate guide portion 101, and the upper guide portion 111. More specifically, the second camera 62 is positioned so that it can capture images of not only the side surface of the solvent supply nozzle 51B but also the inner peripheral end of the intermediate guide portion 101 (i.e., the inner peripheral end of the inclined wall 103) and the inner peripheral end of the upper guide portion 111 (i.e., the inner peripheral end of the opening wall 114). The presence or absence of an abnormality is then determined for the solvent supply nozzle 51B, the intermediate guide portion 101, and the upper guide portion 111 based on the height information. This prevents processing of the wafer W with an abnormality present, thereby preventing a decrease in yield. Note that in the figures illustrating the second embodiment, the components mounted on the main body 60 of the inspection wafer 6, other than the second camera 62, are not shown.

[0074] The preparations for the above-mentioned inspection (abnormality determination) will be described with reference to FIGS. 15 to 17. This preparation, which is a calibration operation, involves setting a reference height in the image acquired by the second camera 62 and acquiring the pixel pitch in the vertical direction of the image for each of the solvent supply nozzle 51B, the intermediate guide portion 101, and the upper guide portion 111, which are the objects to be detected for abnormality. Note that the pixel pitch is the correspondence between the number of pixels and the actual distance, and more specifically, the actual distance per pixel. For this preparation, a scale 94 is used as a jig, for example. The linear edge of this scale 94 on the side where the scale is provided is indicated as 95.

[0075] As described above, the diameter of the main body 60 of the inspection wafer 6 is the same as the diameter of the wafer W. An arbitrary position on the circumferential edge of the main body 60 is set as the reference position A0. This reference position A0 is a position where imaging can be performed by shifting the scale 94 in the radial direction of the main body 60 with respect to the reference position A0, as will be described later, and is, for example, a point that overlaps with the optical axis of the second camera 62 in a plan view.

[0076] FIG. 15 shows the preparations for inspecting the solvent supply nozzle 51B. Assuming that the lower end of the solvent supply nozzle 51B in the processing position is positioned A1 mm away from the reference position A0 toward the center of the wafer W in the radial direction of the wafer W, an operator first places the main body 60 of the inspection wafer 6 on an arbitrary horizontal surface 105. Then, a scale 94 is vertically positioned on the surface of the main body 60 at a position A1 mm away from the reference position A0 along the radial direction of the main body 60. More specifically, the scale 94 is positioned so that the graduations of the scale 94 are aligned vertically and the edge 95 of the scale 94 extends vertically at a position A1 mm away from the reference position A0 in the radial direction of the main body 60. The scale 94 positioned in this manner is then imaged by the second camera 62 to obtain image data.

[0077] Next, the operator determines the pixel at the height indicated by a specific mark on the scale 94 in the image data as the reference height pixel B1. The height indicated by this specific mark is the height of the bottom end of the solvent supply nozzle 51B when the solvent supply nozzle 51B is positioned at the normal processing position, and is designated as the reference height C1. In addition, the operator obtains the pixel pitch (designated pixel pitch 1) from the number of pixels between adjacent marks on the scale 94 in the image data.

[0078] The preparation for inspecting the intermediate guide portion 101 and the upper guide portion 111 is similar to the preparation for the solvent supply nozzle 51B, except for the placement of the scale 94. The preparation for the intermediate guide portion 101 will be described in detail with reference to FIG. 16 , focusing on the differences from the preparation for the solvent supply nozzle 51B. When the cup 4 is properly assembled in the intermediate guide portion 101, its upper end is positioned A2 mm away from the reference position A0, radially outward from the wafer W. In this case, the operator positions the scale 94 at the position A2 mm away from the reference position A0 so that the edge 95 extends vertically. The operator then acquires image data of the scale 94 using the second camera 62. The operator detects the scale marking in the image data, which indicates the height (reference height C2) of the upper end of the intermediate guide portion 101 when the cup 4 is properly assembled, and determines the pixel at the height where the scale marking is captured as the reference height pixel B2. Also, the pixel pitch (assumed to be pixel pitch 2) is obtained from the scale 94 in the image data.

[0079] Furthermore, when the cup 4 is assembled correctly with respect to the upper guide portion 111, the lower end of the opening wall 114 is positioned A3 mm away from the reference position A0 in the radial direction of the wafer W. In this case, the worker positions the scale 94 so that the edge 95 extends vertically at a position A3 mm away from the reference position A0, as shown in FIG. 17 . The worker then acquires image data of this scale 94 using the second camera 62. The worker detects a scale in this image data that indicates the height (reference height C3) of the lower end of the opening wall 114 when the cup 4 is assembled correctly, and determines the pixel at the height where this scale is captured as the reference height pixel B3. The worker also acquires a pixel pitch (pixel pitch 3) from the scale 94 in the image data.

[0080] The reference height pixels B1 to B3 and pixel pitches 1 to 3 obtained as described above are stored in the memory 84 of the computing device 8 by an operator. The memory 84 corresponds to a first storage unit, with pixel pitches 1 and 2 corresponding to conversion information for the cup, and pixel pitch 3 corresponding to conversion information for the nozzle. Furthermore, if multiple inspection wafers 6 are used, it is preferable to obtain the reference height pixels B1 to B3 and pixel pitches 1 to 3 for each inspection wafer 6 and store them in the memory 84, taking into consideration differences in operation accuracy and assembly accuracy between the inspection wafers 6.

[0081] Furthermore, while pixel pitches 1 to 3 were calculated using a method based on the number of pixels between adjacent graduations on the scale 94 in the image, this method is not limited to this. Another example of a method is to use the structure of the cup 4 in the image. This method uses the actual position of the test object as a reference, thereby further improving the accuracy of the measurement results. Specifically, the control unit 20 controls the lift mechanism 36 so that the lift pins 35 are raised by 1 mm while the test wafer 6 is placed on them. It also controls the second camera 62 to capture images of the upper end 106 of the intermediate guide portion 101 before and after this lifting operation. Then, by determining how many pixels the position of the upper end 106 has changed in the two images acquired before and after the lifting operation, pixel pitch 2 can be calculated. While the acquisition of pixel pitch 2 has been described as a representative example, other pixel pitches can also be similarly obtained from images acquired by changing the height of the test wafer 6 relative to the test object.

[0082] The inspection performed after the above-described preparations will be described, focusing on the differences from the inspection described in the first embodiment. First, the inspection wafer 6 is transported to the resist film forming module 3 and adsorbed onto the spin chuck 31. Then, the solvent supply nozzle 51B moves to the processing position, and the spin chuck 31 is intermittently rotated, and when the rotation is stopped, the second camera 62 takes an image.

[0083] The following explanation will be made using the schematic diagram in Fig. 18. Fig. 18 is a schematic diagram showing one of the acquired image data, in which the intermediate guide portion 101 in the image is indicated by a dot. Components other than the intermediate guide portion 101 are not shown. First, the upper end 106 of the intermediate guide portion 101 in the image data is detected, and the number of pixels between the pixel in which the upper end 106 appears and the reference height pixel B2 (shown as H10 in the figure) is detected.

[0084] The detected number of pixels is then multiplied by pixel pitch 2 to calculate the height difference between the upper end 106 and reference height C2. This height difference (the distance between the upper end 106 and reference height C2) is calculated from each piece of acquired image data, and it is determined whether or not it falls within a preset tolerance range. Then, for example, if it is determined that all of the height differences fall within the tolerance range, the height of the intermediate guide portion 101 is determined to be normal, and if any of the height differences does not fall within the tolerance range, the height of the intermediate guide portion 101 is determined to be abnormal.

[0085] Furthermore, the lower end of the opening wall 114 of the upper guide portion 111 is detected in each image data, the number of pixels between the pixel of this lower end and the reference height pixel B3 is detected, and the number of pixels is multiplied by pixel pitch 3 to calculate the height difference between the lower end of the opening wall 113 and the reference height C3. If it is determined that all of the height differences obtained from each image data for the upper guide portion 111 in this way fall within the allowable range, the height of the upper guide portion 111 is considered to be normal, and if any of the height differences does not fall within the allowable range, the height of the upper guide portion 111 is considered to be abnormal.

[0086] Then, from each of the acquired image data, an image of the solvent supply nozzle 51B is selected. The number of pixels between the pixel at the bottom of the solvent supply nozzle 51B and the reference height pixel B1 in the selected image data is multiplied by pixel pitch 1 to calculate the height difference between the bottom of the solvent supply nozzle 51B and the reference height C1. If this height difference is not within the allowable range, it is determined that the height of the solvent supply nozzle 51 is abnormal.

[0087] As described above, according to the second embodiment, the reference height and pixel pitch are acquired in advance as advance preparation data for each inspection object. Then, inspection is performed based on this advance preparation data and image data acquired when the inspection wafer 6 is transported to the resist film formation module 3, thereby making it possible to accurately determine whether there is an abnormality in the height of each of the inspection objects, namely, the solvent supply nozzle 51B, the intermediate guide portion 101, and the upper guide portion 111.

[0088] In the above inspection example, the upper end of the inner periphery of the inclined wall 103 of the intermediate guide portion 101 is the detection target in the image, and the lower end of the inner periphery of the opening wall 114 of the upper guide portion 111 is the detection target in the image, and these detection targets are compared with the reference height. However, the detection target may be any portion that is relatively easy to detect in the acquired image. Therefore, the detection target is not limited to the above-mentioned portions. For example, with respect to the upper guide portion 111, the upper end of the inner periphery of the opening wall 114 may be the detection target, and an abnormality may be determined by comparing the upper end with the reference height corresponding to that upper end.

[0089] The plan view of Fig. 19 shows another example of the configuration of the inspection wafer 6 used in the second embodiment. The plan view of Fig. 19 shows an example in which three second cameras 62 are provided in the main body 60 of the inspection wafer 6, and for convenience of explanation, these are distinguished from one another as cameras 62A, 62B, and 62C. The cameras 62A to 62C have the same focal length. The cameras 62A to 62C are located at different radial positions in the main body 60, and in plan view, the cameras 62A, 62B, and 62C are closer to the center P1 of the main body 60 of the inspection wafer 6 in this order.

[0090] Image data from cameras 62A, 62B, and 62C is used to determine whether there are any abnormalities in the heights of the solvent supply nozzle 51B, the intermediate guide portion 101, and the upper guide portion 111. That is, cameras 62A, 62B, and 62C are positioned to obtain an appropriate depth of field depending on the respective positions of the solvent supply nozzle 51B, the intermediate guide portion 101, and the opening wall 114 of the upper guide portion 111, which are the objects of inspection. In this manner, a camera may be provided for each object of inspection. Note that in FIG. 19, for ease of understanding, the inclined wall 103 of the intermediate guide portion 101 is indicated by dots, and the opening wall 114 of the upper guide portion 111 is indicated by hatching.

[0091] As described in the configuration of the second camera 62 in the first embodiment, each of the cameras 62A to 62C may be provided with a height adjustment unit that appropriately adjusts the height of the camera relative to the main body 60 so that the imaged target is positioned at the center of the image when the target is at a normal height. When the height of the upper end of the intermediate guide 101 is compared with the reference height pixel B2 as described in FIGS. 16 and 18, the camera 62B may be positioned at a height where the reference height pixel B2 is located at the center of the image. When the height of the lower end of the opening wall 114 of the upper guide 111 is compared with the reference height pixel B3 as described in FIG. 17, the camera 62C may be positioned at a height where the reference height pixel B3 is located at the center of the image.

[0092] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, modifications, and combinations may be made to the above-described embodiments without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0093] W wafer 1. Information Acquisition System 2. Substrate processing equipment 31 Spin Chuck 4 cups 51B Solvent supply nozzle 6 Test wafer 6 61 First Camera 62 Second Camera 80 Programs

Claims

1. a substrate holder that holds and rotates the substrate; a cup surrounding the substrate held by the substrate holding unit, an information-acquiring body held by the substrate holding unit in place of the substrate; an imaging unit provided in the information acquisition body for capturing an image of the cup and acquiring image data; an acquisition unit that acquires information about the height of the cup based on the image data; Equipped with the cup having a sidewall and an intermediate annular body projecting from the sidewall at a height below the top end; obtaining a first distance related to a height of the intermediate annular body as information regarding the height of the cup; a first storage unit is provided that stores conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding unit and an inner peripheral end of the intermediate annular body into a distance; The acquisition unit acquires the first distance based on the conversion information for the cup.

2. a substrate holder that holds and rotates the substrate; a cup surrounding the substrate held by the substrate holding unit, an information-acquiring body held by the substrate holding unit in place of the substrate; an imaging unit provided in the information acquisition body for capturing an image of the cup and acquiring image data; an acquisition unit that acquires information about the height of the cup based on the image data; Equipped with the cup includes a lower member provided below the substrate held by the substrate holding part, and a protrusion provided on the lower member so as to protrude upward; the imaging unit images the top surface of the protrusion, the acquisition unit acquires a second distance between the substrate and the protrusion as information related to the height of the cup; a first storage unit is provided that stores conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding unit and the lower member into a distance; The acquisition unit acquires the second distance based on the conversion information for the cup.

3. 3. The information acquisition system for a substrate processing apparatus according to claim 2, further comprising a first lifting mechanism for changing the relative height between the substrate holder and the cup in accordance with the second distance.

4. The cup has a side wall and an annular protrusion formed to protrude from the side wall toward the center of the cup, 3. An information acquisition system for a substrate processing apparatus as described in claim 1 or 2, wherein the imaging unit is provided on the information acquisition body so that the inner end of the annular protrusion at the position set for imaging by the imaging unit is positioned at the center height of the image acquired by the imaging unit.

5. 3. The information acquiring system for a substrate processing apparatus according to claim 1, wherein the imaging unit is provided so that the height of the imaging unit is adjustable on the information acquiring body.

6. 1. A computing device for acquiring information related to a substrate processing apparatus including a substrate holder that holds and rotates a substrate, and a cup that surrounds the substrate held by the substrate holder, a storage unit in which image data acquired by an imaging unit included in an information acquisition body held by the substrate holding unit instead of the substrate in order to image the cup; and an acquisition unit that acquires information about the height of the cup based on the image data; Equipped with the cup having a sidewall and an intermediate annular body projecting from the sidewall at a height below the top end; obtaining a first distance related to a height of the intermediate annular body as information regarding the height of the cup; a first storage unit is provided that stores conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding unit and an inner peripheral end of the intermediate annular body into a distance; The acquisition unit is a calculation device that acquires the first distance based on conversion information for the cup.

7. 1. A computing device for acquiring information related to a substrate processing apparatus including a substrate holder that holds and rotates a substrate, and a cup that surrounds the substrate held by the substrate holder, a storage unit in which image data acquired by an imaging unit included in an information acquisition body held by the substrate holding unit instead of the substrate in order to image the cup; and an acquisition unit that acquires information about the height of the cup based on the image data; Equipped with the cup includes a lower member provided below the substrate held by the substrate holding part, and a protrusion provided on the lower member so as to protrude upward; the imaging unit images the top surface of the protrusion, acquiring a second distance between the substrate and the protrusion as information about the height of the cup; a first storage unit is provided that stores conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding unit and the lower member into a distance; The acquisition unit is a calculation device that acquires the second distance based on conversion information for the cup.

8. 1. An information acquisition method for acquiring information about a substrate processing apparatus including a substrate holder that holds and rotates a substrate, a nozzle that supplies a processing liquid to a surface of the rotating substrate, and a cup that surrounds the substrate held by the substrate holder, a holding step of holding an information-acquiring object instead of the substrate by the substrate holding unit; an imaging unit provided in the information acquisition body capturing an image of the cup to acquire image data; acquiring information about the height of the cup based on the image data by an acquisition unit; Equipped with the cup having a sidewall and an intermediate annular body projecting from the sidewall at a height below the top end; obtaining information about the height of the cup includes obtaining a first distance related to the height of the intermediate annular body; An information acquisition method for a substrate processing apparatus, comprising: a step of acquiring the first distance based on conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding portion and the inner end of the intermediate annular body into a distance.

9. 1. An information acquisition method for acquiring information about a substrate processing apparatus including a substrate holder that holds and rotates a substrate, a nozzle that supplies a processing liquid to a surface of the rotating substrate, and a cup that surrounds the substrate held by the substrate holder, a holding step of holding an information-acquiring object instead of the substrate by the substrate holding unit; an imaging unit provided in the information acquisition body capturing an image of the cup to acquire image data; acquiring information about the height of the cup based on the image data by an acquisition unit; Equipped with the cup includes a lower member provided below the substrate held by the substrate holding part, and a protrusion provided on the lower member so as to protrude upward; the step of acquiring information about the height of the cup is a step of acquiring a second distance between the substrate and the protrusion, An information acquisition method for a substrate processing apparatus, comprising a step of acquiring the second distance based on conversion information for a cup for converting the number of pixels between a reference height in image data acquired by the information acquisition body held by the substrate holding portion and the lower member into a distance.

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