JP7153521B2 - SUBSTRATE PROCESSING APPARATUS AND INSPECTION METHOD - Google Patents

Description

The present disclosure relates to a substrate processing apparatus and an inspection method.

Patent Literature 1 discloses a flow-down determination method for determining a flow-down state of a liquid flowing down from a nozzle positioned above an object to be processed toward the upper surface of the object to be processed. In this method, imaging is performed with the flow path of the liquid from the nozzle to the upper surface of the object to be processed included in the imaging field of view. Next, in the captured image, the total value of the pixel values of the pixels belonging to each pixel row composed of pixels arranged in one row along the liquid flowing direction in the evaluation target area corresponding to the flow path is calculated. Then, it is determined whether or not the liquid is flowing down based on the variation of the total value along the orthogonal direction perpendicular to the flowing direction.

JP 2017-29883 A

A technique according to the present disclosure improves the quality of a captured image used for inspection during processing in a substrate processing apparatus that processes a substrate to be processed.

One aspect of the present disclosure is a substrate processing apparatus for processing a substrate to be processed, comprising: a rotation holding unit that holds and rotates the substrate to be processed; a light source for irradiating the imaging region of the imaging unit with light; an inspection unit for performing an inspection based on an imaging result of the imaging unit; and a selection unit that selects based on the orientation of the substrate to be processed when it is received.

According to the present disclosure, it is possible to improve the quality of a captured image used for inspection during processing in a substrate processing apparatus that processes a substrate to be processed.

1 is a plan view schematically showing the outline of the configuration of a substrate processing system provided with a resist film forming apparatus as a substrate processing apparatus according to the first embodiment; FIG. 1 is a front view schematically showing the outline of the configuration of a substrate processing system provided with a resist film forming apparatus as a substrate processing apparatus according to the first embodiment; FIG. 1 is a rear view schematically showing the outline of the configuration of a substrate processing system provided with a resist film forming apparatus as a substrate processing apparatus according to the first embodiment; FIG. 1 is a vertical cross-sectional view showing the outline of the configuration of a resist film forming apparatus; FIG. 1 is a cross-sectional view showing an outline of a configuration of a resist film forming apparatus; FIG. 3 is a block diagram showing an outline of a configuration of a control section regarding inspection of the resist film forming apparatus; FIG. FIG. 4 is an explanatory diagram of an inspection target area of imaging results of a camera used for inspection during processing by the resist film forming apparatus; It is a figure explaining that disturbance light affects an imaging result according to the direction of a to-be-processed substrate. 4 is a timing chart showing an example of exposure timing of an imaging element of a camera and output timing of an imaging result from the imaging element; FIG. 10 is a diagram showing the relationship between each imaging result obtained when the direction of the substrate to be processed is shifted by a predetermined angle and the luminance value; FIG. 4 is a diagram for explaining the relationship between the number of rotations of the substrate to be processed, the frame rate of the camera, and the light emission timing of the light source during inspection. FIG. 11 is an explanatory diagram of an inspection target area according to the second embodiment; FIG. 5 is a vertical cross-sectional view showing the outline of the configuration of a resist film forming apparatus according to a second embodiment; FIG. 11 is a block diagram showing the outline of the configuration of a control unit for inspection of a resist film forming apparatus as a substrate processing apparatus according to a third embodiment;

In the photolithography process in the manufacturing process of semiconductor devices, etc., a series of processes including a resist coating process for forming a resist film by supplying a resist solution onto a semiconductor wafer (hereinafter referred to as "wafer") is performed. A predetermined resist pattern is formed on the . The series of processes includes, in addition to the resist coating process described above, a development process for developing a resist film exposed to a predetermined pattern. This series of processes is performed by a coating and developing system equipped with various processing apparatuses for processing wafers, a transfer apparatus for transferring wafers, and the like.

In this coating and developing system, the liquid processing apparatus for performing processing using a processing liquid such as a resist liquid among the above-described processing apparatuses includes a spin chuck that holds and rotates a wafer, and a wafer held by the spin chuck for processing. and a processing liquid supply nozzle for supplying the liquid. In this liquid processing apparatus, for example, a rotation process is performed in which the spin chuck is rotated while the processing liquid is supplied from the processing liquid supply nozzle to the center of the wafer held by the spin chuck.

In the rotation process, it may be necessary to take an image of the vicinity of the ejection port of the treatment liquid supply nozzle, analyze the imaged result, and determine the ejection state from the treatment liquid supply nozzle. A technique for this determination is disclosed in Japanese Unexamined Patent Application Publication No. 2002-200013. In Japanese Patent Laid-Open No. 2004-100001, an imaging field of view includes an image of a liquid flow path from a nozzle to the upper surface of an object to be processed, and the state of liquid flow from the nozzle is determined based on the imaging result.

By the way, there is a demand for higher precision in inspections of substrate processing apparatuses, such as inspections for determining ejection states from processing liquid supply nozzles. In order to improve the accuracy, it is necessary to acquire high-quality captured images when using captured images for inspection. Regarding this point, Patent Document 1 does not disclose or suggest anything.

Therefore, the technology according to the present disclosure improves the quality of captured images used for inspection during processing in a substrate processing apparatus that processes substrates to be processed.

A substrate processing apparatus and an inspection method according to the present embodiment will be described below with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

(First embodiment)
FIG. 1 is an explanatory diagram schematically showing the outline of the internal configuration of a substrate processing system 1 including a resist film forming apparatus as a substrate processing apparatus according to the first embodiment. 2 and 3 are a front view and a rear view, respectively, schematically showing the outline of the internal configuration of the substrate processing system 1. FIG. In the present embodiment, an example will be described in which the substrate processing system 1 is a coating and developing system that performs coating processing and development processing on a wafer W as a substrate to be processed.

As shown in FIG. 1, the substrate processing system 1 includes a cassette station 10 into which a cassette C containing a plurality of wafers W is loaded and unloaded, and a processing station equipped with a plurality of various processing apparatuses for performing predetermined processing on the wafers W. 11 and. The substrate processing system 1 has a configuration in which a cassette station 10, a processing station 11, and an interface station 13 for transferring wafers W between an exposure apparatus 12 adjacent to the processing station 11 are connected integrally. is doing.

A cassette mounting table 20 is provided in the cassette station 10 . The cassette mounting table 20 is provided with a plurality of cassette mounting plates 21 on which the cassettes C are mounted when the cassettes C are carried in and out of the substrate processing system 1 .

The cassette station 10 is provided with a wafer transfer device 23 which is movable on a transfer path 22 extending in the X direction in the figure. The wafer transfer device 23 is movable in the vertical direction and around the vertical axis (.theta. direction), and is arranged between the cassette C on each cassette mounting plate 21 and the transfer device of the third block G3 of the processing station 11, which will be described later. The wafer W can be transported between

The processing station 11 is provided with a plurality of, for example, four blocks G1, G2, G3, and G4 each having various devices. For example, a first block G1 is provided on the front side of the processing station 11 (negative direction in the X direction in FIG. 1), and a second block G1 is provided on the back side of the processing station 11 (positive direction in the X direction in FIG. 1). A block G2 of is provided. A third block G3 is provided on the cassette station 10 side of the processing station 11 (negative Y direction side in FIG. 1), and the interface station 13 side of the processing station 11 (positive Y direction side in FIG. 1). is provided with a fourth block G4.

In the first block G1, as shown in FIG. 2, a plurality of liquid processing devices such as a developing processing device 30, a lower antireflection film forming device 31, a resist film forming device 32, and an upper antireflection film forming device 33 are arranged from below. arranged in this order.
The development processing device 30 develops the wafer W. As shown in FIG.
The lower antireflection film forming apparatus 31 forms an antireflection film (hereinafter referred to as “lower antireflection film”) on the wafer W under the resist film.
The resist film forming device 32 supplies a resist liquid to the wafer W to form a resist film.
The upper antireflection film forming apparatus 33 forms an antireflection film (hereinafter referred to as “upper antireflection film”) on the resist film of the wafer W. As shown in FIG.

For example, three development processing devices 30, lower antireflection film forming devices 31, resist film forming devices 32, and upper antireflection film forming devices 33 are arranged horizontally. The number and arrangement of the developing device 30, the lower antireflection film forming device 31, the resist film forming device 32, and the upper antireflection film forming device 33 can be arbitrarily selected.

In the development processing device 30, the lower antireflection film forming device 31, the resist film forming device 32, and the upper antireflection film forming device 33, for example, spin coating is performed on the wafer W using a predetermined processing liquid. In spin coating, for example, the processing liquid is discharged onto the wafer W from a processing liquid supply nozzle, and the wafer W is rotated to spread the processing liquid on the surface of the wafer W. FIG.

In the second block G2, as shown in FIG. 3, a heat treatment device 40, an adhesion device 41, and a peripheral exposure device 42 are arranged vertically and horizontally.
The heat treatment apparatus 40 performs heat treatment such as heating and cooling of the wafer W. FIG.
The adhesion device 41 is for enhancing the fixability between the resist liquid and the wafer W. As shown in FIG.
The periphery exposure device 42 exposes the periphery of the wafer W to light.
The number and arrangement of these heat treatment devices 40, adhesion devices 41, and edge exposure devices 42 can be arbitrarily selected.

For example, in the third block G3, a plurality of transfer devices 50, 51, 52, 53, 54, 55 and 56 are provided in order from the bottom. In addition, a plurality of delivery devices 60, 61, 62 are provided in order from the bottom in the fourth block G4.

As shown in FIG. 3, a wafer transfer area D is formed in an area surrounded by first block G1 to fourth block G4. A wafer transfer device 70 is arranged in the wafer transfer area D. As shown in FIG.

Each of the wafer transfer devices 70 has a transfer arm 70a movable in, for example, the Y direction, the X direction, the .theta. direction, and the vertical direction. A plurality of wafer transfer devices 70 are arranged vertically, and each wafer transfer device 70 moves within the wafer transfer region D and, for example, transfers the wafer W to a predetermined device at approximately the same height in each of the blocks G1 to G4. can be transported.

Further, in the wafer transfer area D, a shuttle transfer device 80 is provided for transferring the wafer W linearly between the third block G3 and the fourth block G4.

The shuttle transport device 80 is linearly movable in the Y direction of FIG. 3, for example. The shuttle transfer device 80 moves in the Y direction while supporting the wafer W, and can transfer the wafer W between the transfer device 52 of the third block G3 and the transfer device 62 of the fourth block G4.

As shown in FIG. 1, a wafer transfer device 90 is provided next to the third block G3 on the positive side in the X direction. The wafer transfer device 90 has a transfer arm 90a movable in, for example, the X direction, the θ direction, and the vertical direction. The wafer transfer device 90 can move up and down while supporting the wafer W to transfer the wafer W to each transfer device in the third block G3.

The interface station 13 is provided with a wafer transfer device 100 and a transfer device 101 . The wafer transfer device 100 has a transfer arm 100a movable in, for example, the Y direction, the θ direction, and the vertical direction. The wafer transfer device 100 supports the wafer W on, for example, a transfer arm 100a, and can transfer the wafer W between the transfer devices, the transfer device 101, and the exposure device 12 in the fourth block G4.

A controller 200 is provided in the substrate processing system 1 described above.
The control unit 200 is configured by a computer including, for example, a CPU and memory, and has a program storage unit (not shown). The program storage unit stores programs for controlling various processes in the substrate processing system 1 . The program may be recorded in a computer-readable storage medium and installed in the control unit 200 from the storage medium.

Here, the configuration of the resist film forming apparatus 32 described above will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a longitudinal sectional view showing an outline of the structure of the resist film forming apparatus 32, and FIG. 5 is a transverse sectional view showing an outline of the structure of the resist film forming apparatus 32. As shown in FIG.

The resist film forming apparatus 32 has a processing container 110 whose inside can be sealed as shown in FIG. As shown in FIG. 5 , a loading/unloading port 111 for the wafer W is formed on the side surface of the processing container 110 , and the loading/unloading port 111 is provided with an opening/closing shutter 112 .

A spin chuck 120 is provided in the central portion of the processing container 110 as a rotation holding portion that holds and rotates the wafer W. As shown in FIG. The spin chuck 120 has a horizontal upper surface, and the upper surface is provided with a suction port (not shown) for sucking the wafer W, for example. The wafer W can be sucked and held on the spin chuck 120 by suction from this suction port.

The spin chuck 120 can be rotated at a predetermined speed by a chuck drive unit 121 having a motor or the like, for example. Further, the chuck drive unit 121 is provided with a lift drive mechanism (not shown) such as a cylinder, and the spin chuck 120 can be lifted up and down. Note that, below the spin chuck 120, lifting pins (not shown) are provided for supporting the wafer W from below and lifting it up and down.

A cup 122 is provided for the spin chuck 120 so as to surround the wafer W held by the spin chuck 120 in the processing container 110 . The cup 122 receives and collects the liquid that scatters or drops from the wafer W.

As shown in FIG. 5, a rail 130 extending along the Y direction (horizontal direction in FIG. 5) is formed on the negative side of the cup 122 in the X direction (downward in FIG. 5). The rail 130 is formed, for example, from the outside of the cup 122 in the negative direction in the Y direction (left direction in FIG. 5) to the outside in the positive direction in the Y direction (right direction in FIG. 5). An arm 131 is provided on the rail 130 .

Arm 131 supports a resist liquid supply nozzle 132 as a processing liquid supply unit that supplies resist liquid to wafer W. As shown in FIG. The arm 131 is movable on the rail 130 by the nozzle driving section 133 . As a result, the resist liquid supply nozzle 132 can move from a standby section 134 installed outside the cup 122 in the positive direction in the Y direction to above the central portion of the wafer W in the cup 122, It can move in the radial direction of the wafer W above. Further, the arm 131 can be moved up and down by the nozzle driving section 133, and the height of the resist liquid supply nozzle 132 can be adjusted. The resist liquid supply nozzle 132 is connected to a resist liquid supply device M that supplies the resist liquid.

In addition, a camera 140 as an imaging unit is provided in the processing container 110 so as to include the surface of the wafer W held by the spin chuck 120 in an imaging area. The imaging area of the camera 140 may be set so as to include only a part of the surface of the wafer W instead of the entire surface of the wafer W as long as the imaging range necessary for inspection is included. The camera 140 is mounted, for example, on the top wall 113 of the processing container 110 via a fixing member (not shown) so as to be disposed at a position that does not interfere with loading/unloading of the wafer W and movement of the resist solution supply nozzle 132. Fixed. A CCD camera, for example, can be used as the camera 140 .
The camera 140 captures images at a predetermined frame rate during inspection. Note that the imaging interval and the exposure time of the imaging element of the camera 140 are different between the time of inspection and the time of pre-inspection performed prior to the inspection, which will be described later.

Furthermore, a light source 150 is provided in the processing container 110 to irradiate the imaging area of the camera 140 with light. The light source 150 is arranged at a position where the wafer W held by the spin chuck 120 is sandwiched between the camera 140 and the wafer W in a plan view, and which does not interfere with loading/unloading of the wafer W and movement of the resist liquid supply nozzle 132 . ing. This light source 150 is fixed above the inner wall of the cup 122, for example.

The timing of imaging by the camera 140 and the timing of light emission of the light source 150 are controlled by the control unit 200, and the imaging results of the camera 140 are output to the control unit 200 and used for inspection and the like.

In the resist film forming apparatus 32 configured as described above, the camera 140 and the light source 150 are controlled, and the resist film forming apparatus 32 under processing is inspected based on the imaging result of the camera 140 .

Next, the configuration of the control unit 200 regarding inspection of the resist film forming apparatus 32 will be described. FIG. 6 is a block diagram showing an outline of the configuration of the control section 200 relating to the inspection. FIG. 7 is an explanatory diagram of an inspection target area in the imaging result of the camera 140 used for inspection, and shows an example of an image captured by the camera 140. As shown in FIG. FIGS. 8A and 8B are diagrams for explaining how ambient light affects imaging results depending on the orientation of the wafer W, and schematically show captured images of the wafer W. FIG. 8(B), the orientation of the wafer W is different. In FIG. 8, the symbol N indicates a notch that serves as a reference for the orientation of the wafer W. As shown in FIG.

The control unit 200 has a storage unit 201, an inspection unit 202, a selection unit 203, a pre-acquisition unit 204, and a determination unit 205, as shown in FIG.
The storage unit 201 stores various information regarding inspection of the resist film forming apparatus 32 .

The inspection unit 202 inspects the resist film forming apparatus 32 being processed based on the imaging result of the camera 140 selected by the selection unit 203 . For example, the inspection unit 202 cuts out an inspection target area from the imaging result, and inspects the resist film forming apparatus 32 based on the cut-out imaging result. For example, as shown in FIG. 7, the inspection target area P is set to an area corresponding to the vicinity of the center of the surface of the wafer W. As shown in FIG. When the inspection target area P is set in this way, the control unit 200 determines whether or not the liquid film at the center of the wafer W has a desired outer peripheral shape ( inspection). The peripheral shape of the liquid film can be obtained based on the difference in brightness (brightness/darkness) in the captured image, and the above determination is performed, for example, by pattern matching with a reference image. A reference image is acquired in advance and stored in the storage unit 201 . Note that the area to be inspected and the contents of the inspection are not limited to those described above.

The selection unit 203 selects the result of imaging by the camera 140 to be used for inspection by the inspection unit 202 . The selection of the imaging result in the selection unit 203 is based on the orientation of the rotating wafer W held by the spin chuck 120 when the imaging result was obtained (hereinafter, sometimes abbreviated as "orientation of the wafer W"). based on The reason for selecting the imaging results in this manner is as follows.

The imaging area of camera 140 includes the surface of wafer W held on spin chuck 120 as described above. When an IC (Integrated Circuit) pattern is formed on the surface of the wafer W, the influence of the light emitted from the light source 150 and reflected by the IC pattern, that is, ambient light, on the imaging result changes depending on the orientation of the wafer W. For example, assume that when the orientation of the wafer W is as shown in FIG. 8A, the luminance near the center of the wafer W increases in the captured image due to ambient light. In this case, when the orientation of the wafer W is rotated by 90 degrees from the state shown in FIG. 8A to the state shown in FIG. Then, in the imaged result, when the portion where the brightness is increased due to the disturbance light overlaps with the inspection target region P, the inspection based on the imaged result cannot be accurately performed.

Therefore, as described above, the selection unit 203 selects the imaging result used for inspection based on the orientation of the wafer W when the imaging result was obtained. Specifically, the selection unit 203 selects the orientation of the wafer W in which the brightness of the inspection target region is high even in a normal state (for example, a state in which the resist liquid is not discharged or a liquid film of the resist liquid is not formed). Select to exclude imaging results. A pre-acquisition unit 204 and a determination unit 205 are provided to enable such selection.

The pre-acquisition unit 204 controls the spin chuck 120, the camera 140, the light source 150, and the like, and acquires imaging results in a plurality of states in which the orientations of the wafer W held by the spin chuck 120 are different from each other prior to inspection.
Based on the imaging results obtained by the pre-acquisition unit 204 in a plurality of states in which the orientation of the wafer W held by the spin chuck 120 is highly different, the determination unit 205 selects the wafer in which the brightness of the inspection target area in the imaging results is high. The orientation of W, ie, the orientation of the wafer W that is inappropriate for imaging for inspection, is determined prior to inspection. Selection is made by the selection unit 203 based on the determination result of the determination unit 205 . A method of judging the inappropriate orientation of the wafer W at the time of imaging for inspection will be described later. In addition, hereinafter, "inappropriate orientation of the wafer W at the time of imaging for inspection" may be omitted as "inappropriate" or the like.

Next, wafer processing performed using the substrate processing system 1 configured as described above will be described. First, a cassette C containing a plurality of wafers W is loaded into the cassette station 10 of the substrate processing system 1, and the wafers W in the cassette C are successively transferred to the transfer device 53 of the processing station 11 by the wafer transfer device 23. .

Next, the wafer W is transported to the heat treatment apparatus 40 of the second block G2 and subjected to temperature control processing. After that, the wafer W is transferred by the wafer transfer device 70 to, for example, the lower antireflection film forming device 31 of the first block G1, and a lower antireflection film is formed on the wafer W. FIG. After that, the wafer W is transferred to the heat treatment apparatus 40 of the second block G2, heat-treated, and temperature-controlled.

Next, the wafer W is conveyed to the adhesion device 41 and subjected to adhesion processing. After that, the wafer W is transferred to the resist film forming device 32 of the first block G1, and a resist film is formed on the wafer W. As shown in FIG. After that, the wafer W is transferred to the heat treatment apparatus 40 and pre-baked. In the pre-baking process, the same process as the heat treatment after the formation of the lower anti-reflection film is performed, and in the heat treatment after the formation of the upper anti-reflection film, the post-exposure bake process, and the post-bake process, which will be described later, the same processes are performed. will be However, the heat treatment apparatuses 40 used for each heat treatment are different from each other.

Next, the wafer W is transferred to the upper antireflection film forming apparatus 33, and an upper antireflection film is formed on the wafer W. FIG. After that, the wafer W is transferred to the heat treatment apparatus 40, heated, and temperature-controlled. After that, the wafer W is transported to the edge exposure device 42 and subjected to edge exposure processing.

Next, the wafer W is transferred to the exposure device 12 and exposed in a predetermined pattern.

The wafer W is then transported to the heat treatment apparatus 40 and subjected to post-exposure baking. After that, the wafer W is transported to, for example, the developing device 30 and developed. After the development process is completed, the wafer W is transported to the heat treatment apparatus 40 and post-baked. Then, the wafer W is transferred to the cassette C on the cassette mounting plate 21 to complete a series of photolithography processes.

Here, processing in the resist film forming apparatus 32 will be described in detail.
In the resist film forming apparatus 32 , the resist film is formed while the inspection unit 202 conducts an inspection based on the result of imaging by the camera 140 . Prior to the inspection and the formation of the resist film, as preprocessing performed for each wafer W, a process of determining an inappropriate orientation of the wafer W at the time of imaging for inspection is performed.

In this process, when the wafer W is sucked and held on the upper surface of the spin chuck 120, the pre-acquisition unit 204 retracts the resist liquid supply nozzle 132 in order to acquire the imaging result used for determining the inappropriate orientation described above. The camera 140 and the like are controlled while the state is maintained. Specifically, the pre-acquisition unit 204 controls the spin chuck so that light is emitted from the light source 150 and an image is captured by the camera 140 in each of a plurality of states in which the orientation of the wafer W held by the spin chuck 120 is different from each other. 120 , camera 140 and light source 150 . More specifically, the pre-acquisition unit 204 shifts the orientation of the wafer W held by the spin chuck 120 by a predetermined angle (division angle) around the rotation axis of the spin chuck 120 from the light source 150 in each of a plurality of states. Control is performed so that light is emitted and an image is captured.

This control is performed, for example, based on an output signal from an encoder (not shown) provided in the chuck driving section 121 while the spin chuck 120 rotates the wafer W at a low rotational speed. The output signals from the encoder used here are the Z-phase signal that is output each time the spin chuck 120 rotates once, and the A-phase signal (or B-phase signal) that is output a predetermined number of times while the spin chuck 120 rotates once. signal). For example, when the orientation of the wafer W is represented by the deviation of the spin chuck 120 from the reference angle, the controller 200 determines that the orientation of the wafer W is 0 degrees when the Z-phase signal from the encoder rises. do. Further, every time the encoder receives a number of A-phase signals (or B-phase signals) corresponding to the division angle, the control unit 200 exposes the imaging element of the camera 140 for a predetermined period of time, and outputs the imaging result from the imaging element. output. FIG. 9 is a timing chart showing an example of the exposure timing of the imaging element of the camera 140 and the output timing of the imaging result from the imaging element. The timing chart in the figure is for the case where the A-phase signal and the B-phase signal are output 5400 times during one rotation of the spin chuck 120 and the division angle is 2 degrees. According to the control based on this timing chart, every time the A phase is input 30 times, the exposure of the imaging device and the output of the imaging result from the imaging device are performed, and the orientation of the wafer W is shifted by 2°. A total of 180 imaging results can be acquired for one rotation of the wafer W. FIG.

When the pre-acquisition unit 204 acquires the imaging result, the determination unit 205 determines whether or not the orientation of the wafer W corresponding to the imaging result is inappropriate for each imaging result. Specifically, first, the determination unit 205 extracts the brightness of the inspection target region (for example, refer to symbol P in FIG. 7) in each imaging result. The luminance to be extracted is, for example, the average luminance value of the pixels included in the inspection target area. The determination unit 205 determines whether or not the orientation of the wafer W corresponding to the imaging result is inappropriate based on the extracted brightness for each imaging result. For example, if the brightness extracted from the imaged result is greater than a predetermined threshold, the determination unit 205 determines that the orientation of the wafer W corresponding to the imaged result is inappropriate.

FIG. 10 is a diagram showing the relationship between each imaging result obtained when the orientation of the wafer W is shifted by 2° and the luminance value. When the imaging result and the luminance value of FIG. 10 are obtained, the determination unit 205 determines the imaging result in which the orientation of the wafer W is 136 to 144° or 316 to 324° where the luminance value exceeds the threshold value (150 in the example of the figure). , it is determined that the orientation of the wafer W corresponding to the imaging result is inappropriate.
Further, the determination unit 205 stores the determination result of whether or not the orientation of the wafer W is inappropriate for each imaging result as the determination result of whether or not the orientation of the wafer W is inappropriate in the storage unit 201 . be memorized.
This ends the preprocessing.

After the pretreatment, a resist film is formed and inspected. Since the inspection is performed in each process for forming the resist film, the formation of the resist film will be explained first.

When forming the resist film, the control unit 200 first moves the resist liquid supply nozzle 132 above the center of the wafer W, and rotates the wafer W at a low rotational speed (eg, 300 rpm) while depositing the resist on the wafer W. A liquid film forming process is performed to supply a liquid and form a liquid film.

When the supply time of the resist solution from the resist solution supply nozzle 132 reaches a predetermined length, the supply of the resist solution is stopped while the number of rotations of the wafer W is maintained. Next, the resist liquid supply nozzle 132 is retracted, and the wafer W is rotated at a high rotational speed (for example, 3000 rpm) to spread the resist liquid supplied to the center of the wafer W over the entire surface of the wafer W to apply a predetermined film thickness. Diffusion treatment is performed to form a film. Next, the wafer W is rotated at a predetermined rotation speed (for example, 1500 rpm), and a drying process for drying the coating film on the wafer W is performed. After that, the wafer W sucked and held by the spin chuck 120 is unloaded from the resist film forming apparatus 32, and the next wafer W is loaded.

In each of the liquid film forming process, the diffusion process, and the drying process described above, an inspection is performed based on the results of imaging by the camera 140 .
During inspection in each process, the control unit 200 causes the camera 140 to capture an image at a predetermined frame rate.
Then, the selection unit 203 selects the imaging result to be used for the inspection based on the determination result of the inappropriate orientation of the wafer W obtained in the preprocessing. Specifically, the imaging result for inspection in each process is selected based on the determination result as to whether or not the orientation of the wafer W is inappropriate for each orientation of the wafer W, which is stored in the pre-processing. be. More specifically, the imaging result used for the inspection is determined based on the determination result, the number of revolutions of the wafer W at the time of imaging for inspection, and the frame rate of the camera 140 at the time of imaging for inspection.

FIG. 11 is a diagram for explaining the relationship between the number of revolutions of the wafer W during inspection imaging, the frame rate of the camera during inspection imaging, and the imaging results used for inspection.
Here, for example, it is assumed that the imaging results and luminance values shown in FIG. 10 have been obtained in the preprocessing, the rotation speed of the wafer W is 900 rpm, and the frame rate is 60 fps. At this time, as shown in FIG. 11, there is no time during which the orientation of the wafer W is inappropriate in the n-th frame and the n+2-th frame, and the orientation of the wafer W is in the intermediate time zone in the n+1-th frame and the n+3-th frame. There may be times when
In this case, the selection unit 203 selects the imaging results of the nth frame and the n+2th frame as the imaging results used for the inspection, and does not select the imaging results of the n+1th frame and the n+3th frame.

Then, the inspection unit 202 performs inspection based on the imaging result selected by the selection unit 203 . As a result, the inspection can be performed accurately regardless of the number of rotations of the wafer W and the frame rate of the camera 140 during imaging for inspection.

If the result of the inspection is that the wafer W is defective, the process corresponding to the inspection is stopped, and the wafer W is unloaded from the resist film forming apparatus 32 without the subsequent processes being performed.

During imaging for inspection, the light source 150 may be turned on all the time, or may be turned on only during a part of each frame. Also, when taking an image for inspection, the exposure time of the imaging device of the camera 140 may be 1/f seconds or less, where f is the frame rate.

According to this embodiment, the imaging result of the camera 140 used for inspection during processing by the resist film forming apparatus 32 is selected based on the orientation of the wafer W when the imaging result is obtained. Therefore, it is possible to limit the imaging results used for the inspection to those that are less affected by ambient light in the inspection target portion. That is, it is possible to improve the quality of the captured image used for the inspection. Therefore, the inspection based on the imaging results can be accurately performed.

Further, according to the present embodiment, in the above-described preprocessing, the camera 140 captures an image while actually irradiating light from the light source 150 in each of a plurality of states in which the orientation of the wafer W held by the spin chuck 120 is different from each other. conduct. Then, an inappropriate orientation of the wafer W is determined based on the imaging result, and an imaging result to be used for inspection is selected based on the determination result. Therefore, as an imaging result used for the inspection, it is possible to accurately obtain an image that is less affected by ambient light in the inspection target area.

(Modified example of the first embodiment)
In the above embodiment, the pretreatment is performed for each wafer W, and the inappropriate orientation of the wafer W is determined. However, when the IC patterns formed on the wafers W of the same lot are common and the following conditions (A) and (B) are satisfied, only the first wafer W of the lot is preliminarily processed. Processing may be performed to determine an inappropriate wafer W orientation. Then, another wafer W in the same lot may be inspected based on the determination result.
(A) The orientation of the wafer W when it is carried into the resist film forming apparatus 32 and placed on the spin chuck 120 is common within the same lot. (B) It is carried into the resist film forming apparatus 32 and placed on the spin chuck 120. The orientation of the spin chuck 120 is always constant when

The case where the above condition (A) is satisfied is, for example, the case where the orientation and transfer route of the wafers W within the lot are common. Further, instead of making the orientation of the wafers W common within the lot, a mechanism may be provided that aligns the orientation of the wafers W by aligning the notch positions of the wafers W in the middle of the transfer path.

(Second embodiment)
FIG. 12 is an explanatory diagram of an inspection target area according to the second embodiment. FIG. 13 is a vertical cross-sectional view showing the outline of the configuration of the resist film forming apparatus according to the second embodiment.

In the first embodiment, the inspection target area P is set at one location. A plurality of areas P to be inspected may be provided. For example, as shown in FIG.
When there are a plurality of inspection target regions P, the selection of the imaging result by the selection unit 203 and the determination of the inappropriate orientation of the wafer W by the determination unit 205 are performed for each inspection target region P.

Further, when there are a plurality of inspection target areas P, inspection may be made different for each inspection target area P. FIG. In other words, the inspection performed by the inspection unit 202 may be of a plurality of types.
In this way, when there are a plurality of inspection types, different light sources may be used for each inspection type, that is, for each inspection target area P.

In the resist film forming apparatus 32 of FIG. 13, in addition to the light source 150 for inspection whose inspection target area is the surface of the wafer W, another light source 160 for inspection whose inspection target area is the resist liquid supply nozzle 132 is provided. It is provided inside the processing container 110 . Both the light source 150 and the light source 160 irradiate the imaging area of the camera 140 with light. The light source 150 mainly irradiates the wafer W, and the light source 160 mainly irradiates the resist liquid supply nozzle 132 . do.
Like the light source 150 , the light source 160 is arranged at a position that does not interfere with loading/unloading of the wafer W and movement of the resist liquid supply nozzle 132 . The light source 160 is, for example, fixed to the ceiling wall 113 of the processing container 110 via a fixing member (not shown).

In the inspection based on the imaging result using the light source 160, the selection unit 203 selects the imaging result to be used for the inspection based on the orientation of the wafer W, similarly to the inspection based on the imaging result using the light source 150. .
However, when an inspection based on imaging results using the light source 160 and an inspection based on imaging results using the light source 150 are performed, the control unit 200 controls the camera 140 so that imaging is performed separately for each inspection.

When performing a plurality of inspections as described above, the control unit 200 switches the type of inspection and the light source used for each imaging frame of the camera 140, for example. Specifically, for example, when imaging an odd-numbered frame, the light source 150 is used as in the first embodiment, and the surface region of the wafer W as the inspection target region is cut out from the imaging result and inspected. Then, when imaging an even-numbered frame, the light source 160 is used, and the area of the resist liquid supply nozzle 132 as the inspection target area is cut out from the imaging result and inspected.

Note that when a plurality of light sources are switched and used as described above, acquisition of imaging results prior to inspection by the pre-acquisition unit 204 and determination of an inappropriate orientation of the wafer W by the determination unit 205 are performed for each light source. will be
Further, when the wavelength of light from each light source is the same, when the pre-acquisition unit 204 acquires the imaging result prior to the inspection, the emission timing of light from each light source is set to be different from each other.
However, when the wavelengths of the light from each light source are different from each other, the light emission timing may be the same for each light source. Then, based on the same imaging result, it is possible to determine the inappropriate orientation of the wafer W at the time of light emission from each light source. As a result, it is possible to shorten the time required for preprocessing when there are a plurality of inspection types and light sources.

(Modification of Second Embodiment)
In the above example, when there are multiple light sources and multiple inspection types, multiple inspection target areas are set with different inspection target areas for each light source and each inspection type. Not limited to this example, when there are a plurality of light sources and inspection types, one inspection target area may be used.

(Third embodiment)

FIG. 14 is a block diagram showing the outline of the configuration of a control unit for inspection of a resist film forming apparatus as a substrate processing apparatus according to the third embodiment.
In the first and second embodiments, the inspection target area P was fixed. In contrast, in the present embodiment, the inspection target region P moves during inspection. The case where the inspection target area P moves during inspection is, for example, the case where the inspection target is the resist liquid supply nozzle 132 that moves during processing.

In the present embodiment, the determination unit 210 determines the orientation of the wafer W that is inappropriate at the time of imaging for inspection at least for each area that can be the inspection target area P. FIG.

Further, the selection unit 211 acquires all the imaging results obtained by the camera 140 when selecting imaging results of the camera 140 used for inspection. At that time, the selection unit 211 determines an inspection target region for each imaging result. For example, when the object to be inspected is the resist liquid supply nozzle 132 that moves during processing, the positional information of the resist liquid supply nozzle 132 when the imaging result is obtained is used to determine the inspection target area. For the positional information of the resist liquid supply nozzle 132, an output pulse signal from a stepping motor (not shown) provided in the nozzle driving section 133 can be used. Information on the elapsed time from the start of the inspection to the acquisition of the imaging result may be used to determine the inspection target region described above.
Then, for each imaging result, the selecting unit 211 determines whether to use the wafer W for inspection based on the determination result of the inappropriate orientation of the wafer W in the determination unit 210 related to the inspection target region P determined for the imaging result. It is determined whether or not, and based on the determination result, the imaging result to be used for the inspection is selected.
In this manner, the selection unit 211 determines whether or not to use the imaging result in which the inspection target area is set for each inspection target area at each time point during the inspection, and based on the determination result, the image is used for the inspection. Select the imaging result.

According to this embodiment, inspection can be performed even when the inspection target area P moves.
Further, in this embodiment, the positional information of the resist liquid supply nozzle 132 when the imaging result was obtained was used when determining the inspection target area for each imaging result. As a result, regardless of process conditions such as the movement speed of the resist liquid supply nozzle 132, the inspection target area can be appropriately determined.

In the above description, the process to be inspected is the process of supplying the resist liquid on the wafer W to form a liquid film, etc., but the process to be inspected is not limited to this. Other treatments, such as a cleaning treatment for removing the above unnecessary matter, may also be used.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments described above may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Note that the following configuration also belongs to the technical scope of the present disclosure.
(1) A substrate processing apparatus for processing a substrate to be processed,
a rotation holding unit that holds and rotates the substrate to be processed;
an imaging unit including, in an imaging area, the surface of the substrate to be processed held by the rotation holding unit;
a light source that irradiates the imaging region of the imaging unit with light;
an inspection unit that performs an inspection based on the imaging result of the imaging unit;
and a selection unit that selects an imaging result to be used for the inspection based on the orientation of the substrate to be processed when the imaging result is obtained.

(2) a pre-acquisition unit that acquires imaging results of a plurality of states in which orientations of the substrate to be processed held by the rotary holding unit are different from each other, prior to the inspection;
a determining unit that determines an inappropriate orientation of the substrate to be processed at the time of imaging for inspection based on imaging results of the plurality of states;
The substrate processing apparatus according to (1), wherein the selection unit selects an imaging result to be used for the inspection based on a determination result of the determination unit.

(3) The selection unit determines the inappropriate orientation of the substrate to be processed by the determination unit, the number of revolutions of the substrate to be processed when the inspection image is captured, and the rotation speed of the image capturing unit when the inspection image is captured. The substrate processing apparatus according to (2) above, wherein an imaging result to be used for the inspection is selected based on a frame rate.

(4) The substrate processing apparatus according to any one of (1) to (3) above, wherein the inspection unit performs the inspection based on the information of the inspection target area of the imaging result.

(5) the inspection target area is plural;
The substrate processing apparatus according to (14), wherein the selection unit selects an imaging result to be used for the inspection for each inspection target area.

(6) the inspection target area moves during the inspection;
The selection unit determines, for each inspection target area at each point in time during the inspection, whether or not to use an imaging result in which the inspection target area is set for the inspection, and performs the inspection based on the determination result. The substrate processing apparatus according to (4) or (5) above, which selects an imaging result to be used for.

(7) the inspection unit performs a plurality of types of inspection;
The light source is provided for each type of inspection,
The substrate processing apparatus according to any one of (1) to (6) above, wherein the inspection type and the light source type are set for each imaging frame.

(8) An inspection method for inspecting a substrate processing apparatus that processes a substrate to be processed,
The substrate processing apparatus is
a rotation holding unit that holds and rotates the substrate to be processed;
an imaging unit including, in an imaging area, the surface of the substrate to be processed held by the rotation holding unit;
a light source that irradiates the imaging area of the imaging unit with light;
The inspection method is
a step of selecting an imaging result to be used for the inspection based on the orientation of the substrate to be processed when the imaging result was obtained;
and a step of performing an inspection based on the imaging result of the imaging unit.

32 resist film forming apparatus 140 camera 150 light source 202 inspection unit 203 selection unit W wafer

Claims (8)

A substrate processing apparatus for processing a substrate to be processed,
a rotation holding unit that holds and rotates the substrate to be processed;
an imaging unit including, in an imaging area, the surface of the substrate to be processed held by the rotation holding unit;
a light source that irradiates the imaging region of the imaging unit with light;
an inspection unit that performs an inspection based on the imaging result of the imaging unit;
and a selection unit that selects an imaging result to be used for the inspection based on the orientation of the substrate to be processed when the imaging result is obtained. a pre-acquisition unit that acquires imaging results of a plurality of states in which orientations of the substrate to be processed held by the rotary holding unit are different from each other, prior to the inspection;
a determining unit that determines an inappropriate orientation of the substrate to be processed at the time of imaging for inspection based on imaging results of the plurality of states;
2. The substrate processing apparatus according to claim 1, wherein said selection unit selects an imaging result used for said inspection based on a determination result of said determination unit. The selection unit selects the result of determination of the inappropriate orientation of the substrate to be processed by the determination unit, the number of revolutions of the substrate to be processed during imaging for inspection, and the frame rate of the imaging unit during imaging for inspection. 3. The substrate processing apparatus according to claim 2, wherein the imaging result to be used for said inspection is selected based on. The substrate processing apparatus according to any one of claims 1 to 3, wherein the inspection unit performs inspection based on information of the inspection target area of the imaging result. The inspection target areas are plural,
The substrate processing apparatus according to claim 4 , wherein the selection unit selects imaging results used for the inspection for each inspection target area. the inspection target area moves during the inspection;
The selection unit determines, for each inspection target area at each point in time during the inspection, whether or not to use an imaging result in which the inspection target area is set for the inspection, and performs the inspection based on the determination result. 6. The substrate processing apparatus according to claim 4, wherein the imaging result used for is selected. The inspection unit performs a plurality of types of inspections,
The light source is provided for each type of inspection,
7. The substrate processing apparatus according to claim 1, wherein said inspection type and said light source type are set for each imaging frame. An inspection method for inspecting a substrate processing apparatus for processing a substrate to be processed, comprising:
The substrate processing apparatus is
a rotation holding unit that holds and rotates the substrate to be processed;
an imaging unit including, in an imaging area, the surface of the substrate to be processed held by the rotation holding unit;
a light source that irradiates the imaging area of the imaging unit with light;
The inspection method is
a step of selecting an imaging result to be used for the inspection based on the orientation of the substrate to be processed when the imaging result was obtained;
and a step of performing an inspection based on the imaging result of the imaging unit.

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