JP2021128977A - Device for end point judgment, and method for end point judgment - Google Patents

Abstract

To provide a device for end point judgment and a method for end point judgment which allow an end point of a removal process to be determined correctly without depending on the level of skill of an operator.SOLUTION: A device for end point judgment is arranged to make judgment about an end point of a removal process. The removal process is a process to remove a reaction product left in a process chamber of a substrate-processing device after a substrate process on a substrate in the substrate-processing device. The device for end point judgment comprises: a detector unit operable to detect, on light from a low-temperature plane lower, in temperature, than a plane to put the substrate on, a light intensity for each of 10 or more wavelength bands included in the light during the removal process in the process chamber; a generator unit operable to generate, on a result of detection by the detector unit for each of the 10 or more wavelength bands, a photographic image of the low-temperature plane showing an intensity distribution of light of the wavelength band; and an image-processing unit operable to assign a color depending on a pixel value to each pixel of the photographic image of the low-temperature plane for a wavelength band corresponding to the reaction product, included in the 10 or more wavelength bands, and generate a pseudo-color image.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an end point determination device and an end point determination method.

Patent Document 1 discloses a cleaning end point detecting device that detects the end point of a cleaning process. In the cleaning treatment in Patent Document 1, the deposits on the inner wall of the reaction chamber are removed as follows. That is, a cleaning gas is introduced into the reaction chamber to generate a cluster cloud due to the reaction between a part of the deposit and the cleaning gas in the reaction chamber, and the remaining part of the deposit is peeled from the inner wall as peeling particles to form a cluster. This is done by exhausting the clouds and exfoliated particles from the reaction chamber together with the cleaning gas. The cleaning end point detection device disclosed in Patent Document 1 irradiates a cluster cloud and separated particles in a reaction chamber with a laser beam to generate scattered laser light by the cluster cloud and separated particles, and a two-dimensional image of the scattered laser light. It has a measuring means for measuring as information and a determining means for determining the end point of the cleaning process based on the two-dimensional image information. In this apparatus, the determination means determines from the two-dimensional image information that the end point of the cleaning process is the time when the density of particles of a predetermined size, which is substantially equal to the particle size of the cluster cloud, drops to a predetermined density.

Japanese Patent No. 3535785

The technique according to the present disclosure provides an end point determination device and an end point determination method capable of accurately determining the end point of the removal process regardless of the skill level of the operator.

One aspect of the present disclosure is an end point determination device for determining the end point of the removal process, and the removal process remains in the processing container of the substrate processing apparatus after the substrate is processed on the substrate by the substrate processing apparatus. It is a process of removing a reaction product, and the end point determination device is based on the light from a low temperature surface which is lower than the surface on which the substrate is placed during the removal process in the processing container. A detection unit that detects light intensity for each of the 10 or more wavelength bands included, and a detection unit that shows the distribution of light intensity in each of the 10 or more wavelength bands based on the detection results of the detection unit. Colors corresponding to pixel values for each pixel of the captured image of the low temperature surface for the generation unit that generates the captured image of the low temperature surface and the wavelength band corresponding to the reaction product contained in the 10 or more wavelength bands. To generate a pseudo-color image, and an image processing unit.

According to the present disclosure, there is provided an end point determination device and an end point determination method capable of accurately determining the end point of the removal process regardless of the skill level of the operator.

It is explanatory drawing which shows the outline of the structure of the processing system including the end point determination apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the outline of the structure of the film forming apparatus as a substrate processing apparatus which the processing system of FIG. 1 has. It is a figure for demonstrating the captured image group generated by the generation part. It is a flowchart for demonstrating an example of the flow of processing performed using the processing system of FIG. It is a figure for demonstrating the generation process of a pseudo color image. It is a figure for demonstrating the generation process of a pseudo color image. It is explanatory drawing which shows typically the outline of the structure of the processing system including the end point determination apparatus which concerns on 2nd Embodiment. It is explanatory drawing which shows the outline of the structure of the processing system including the end point determination apparatus which concerns on the reference embodiment schematically.

For example, in the manufacturing process of a semiconductor device, a substrate processing such as a film forming process is performed on a substrate such as a semiconductor wafer (hereinafter, referred to as “wafer”) by using a substrate processing apparatus.
Since unnecessary reaction products remain in the processing container of the substrate processing apparatus for accommodating the substrates after the substrate treatment, a removal treatment, that is, a cleaning treatment for removing the reaction products has been conventionally performed. The cleaning process is performed by supplying a cleaning gas such as _{NF 3} gas into the processing container after the substrate processing. If this cleaning process is too short, the reaction product remains in the processing container and is mixed as an impurity in the film formed in the next film forming process, for example, and the quality of the film deteriorates. Further, if the cleaning process is too long, the productivity deteriorates in the mass production process of the semiconductor device in which the substrate process such as the film forming process is continuously performed. Therefore, it is necessary to appropriately set the end point of the cleaning process.

By the way, in the substrate processing apparatus, the mounting surface of the substrate is heated, and the portion of the processing container far from the mounting surface is lower than the mounting surface. The reaction product adhering to the low temperature portion does not easily react with the cleaning gas, so that the reaction product is slowly removed by the cleaning process. Therefore, as disclosed in Patent Document 1, when it is determined that the end point of the cleaning process is the time when the density of particles of a predetermined size generated during the cleaning process drops to a predetermined density, the density of the particles generated during the cleaning process is determined. Depending on the measurement position, reaction products may remain in the low temperature part of the processing container even after the cleaning process is completed.

In addition, there is also a method in which an operator opens the processing container and visually confirms whether or not the reaction product remains in the low temperature portion of the processing container, and determines the end point of the cleaning process from the confirmation result. Conceivable. However, in this case, depending on the skill level of the operator, it is not possible to accurately determine whether or not the reaction product remains, so that the end point of the cleaning process cannot be accurately determined.

Therefore, the technique according to the present disclosure provides an end point determination device and an end point determination method capable of accurately determining the end point of the removal process regardless of the skill level of the operator.

Hereinafter, the end point determination device and the end point determination method according to the present embodiment will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

(First Embodiment)
FIG. 1 is an explanatory diagram schematically showing an outline of a configuration of a processing system including an end point determination device according to the first embodiment. FIG. 2 is a cross-sectional view schematically showing an outline of the configuration of a film forming apparatus as a substrate processing apparatus included in the processing system of FIG. FIG. 3 is a diagram for explaining a group of captured images generated by a generation unit described later.

The processing system 1 of FIG. 1 includes a film forming apparatus 2, an imaging apparatus 3, a control apparatus 4, a display apparatus 5, and a printing apparatus 6. The hyperspectral camera 3a described later of the imaging device 3 and the control device 4 constitute an end point determination device according to the present embodiment.

The film forming apparatus 2 performs a film forming process as a substrate process, specifically, a film forming process using plasma on a wafer as a substrate.

As shown in FIG. 2, the film forming apparatus 2 is configured to be decompressible and includes a processing container 10 for accommodating the wafer W.
The processing container 10 has a container body 11 formed in a bottomed cylindrical shape.
A carry-in outlet 11a for the wafer W is provided on the side wall of the container main body 11, and a gate valve 12 for opening and closing the carry-in outlet 11a is provided at the carry-in outlet 11a. Further, an exhaust duct 17, which will be described later, is provided above the carry-in outlet 11a of the container body 11 so as to form a part of the side wall of the processing container 10.

Further, in the processing container 10, a mounting table 20 on which the wafer W is horizontally mounted is provided. The upper surface 20a of the mounting table 20 is a mounting surface on which the wafer is mounted. A heater 21 for heating the wafer W is provided on the upper surface 20a side inside the mounting table 20, and the wafer W mounted on the mounting table 20 can be heated to a desired temperature. The heater 21 is, for example, a resistance heating heater.
The mounting table 20 constitutes a lower electrode. High-frequency power for bias is supplied to the mounting table 20 from the high-frequency power supply 30 provided outside the processing container 10 via the matching unit 30a.

Further, the upper end of the support column 22 extending in the vertical direction is connected to the central portion of the lower surface of the mounting table 20. The lower end of the support column 22 penetrates the opening 11b provided in the bottom wall of the container body 11 and extends to the outside of the processing container 10 and is connected to the elevating mechanism 23. By driving the elevating mechanism 23, the mounting table 20 can move up and down between the transport position indicated by the alternate long and short dash line and the processing position above it. The transfer position is defined when the wafer W is transferred between the transfer mechanism (not shown) of the wafer W entering the processing container 10 from the carry-in port 11a of the processing container 10 and the support pin 26a described later. This is the position where the stand 20 stands by. The processing position is a position where the film forming process is performed on the wafer W.

A flange 24 is provided on the outside of the processing container 10 on the support column 22. A bellows 25 is provided between the flange 24 and the penetrating portion of the support column 22 on the bottom wall of the container body 11 so as to surround the outer peripheral portion of the support column 22. As a result, the airtightness of the processing container 10 is maintained.

Below the mounting table 20 in the processing container 10, a wafer elevating member 26 having a plurality of, for example, three support pins 26a is provided. The wafer elevating member 26 can be moved up and down by the elevating mechanism 27. Further, by moving up and down, the support pin 26a protrudes from the upper surface of the mounting table 20 through the through hole 20b formed in the mounting table 20 for the transfer of the wafer W.

An annular insulating support member 13 is provided on the upper side of the exhaust duct 17 in the processing container 10. A shower head support member 14 made of, for example, quartz is provided on the lower surface side of the insulating support member 13. The shower head support member 14 supports a shower head 15 which is a gas introduction portion for introducing a processing gas into the processing container 10 and constitutes an upper electrode.

The shower head 15 has a disk-shaped head main body 15a and a shower plate 15b connected to the head main body 15a, and a gas diffusion space is provided between the head main body 15a and the shower plate 15b. S1 is formed. The head body portion 15a and the shower plate 15b are made of metal. A gas supply path 15c leading to the gas diffusion space S1 is formed in the head main body 15a, and a large number of gas discharge holes 15d communicating from the gas diffusion space S1 are formed in the shower plate 15b.
Further, high-frequency power for plasma formation is supplied to the shower head 15 from a high-frequency power supply 31 provided outside the processing container 10 via a matching device 31a.

Further, inside the processing container 10, an annular member 16 is provided above the carry-in outlet 11a. The annular member 16 is arranged so as to be close to the outer peripheral surface of the mounting table 20 at the processing position and surround the mounting table 20.

Further, an exhaust duct 17 formed by being curved in an annular shape is provided on the upper portion of the side wall of the processing container 10. The inner peripheral surface side of the exhaust duct 17 is opened in the circumferential direction so that a gap 18 is formed over the entire circumference with the upper surface of the annular member 16.

One end of the exhaust pipe 32 is connected to the exhaust duct 17, and the other end of the exhaust pipe 32 is connected to, for example, an exhaust device 33 configured by a vacuum pump. An APC valve 34 for adjusting the pressure in the processing space S2 is provided on the upstream side of the exhaust pipe 32 with respect to the exhaust device 33. By operating the exhaust device 33, the gas in the processing space S2 reaches the gas passage 17a of the exhaust duct 17 through the gap 18 and is discharged through the exhaust pipe 32.

Further, the processing container 10 is provided with an optical window 19. The optical window 19 is a member that enables imaging by the image pickup apparatus 3 from the outside of the processing container 10 without impairing the airtightness of the processing container 10. The optical window 19 is formed of a material that transmits light emitted from a light source 3b, which will be described later, of the image pickup apparatus 3, and is provided outside the opening 11b in the bottom wall of the container body 11, for example.

One end of the gas supply pipe 41 is connected to the gas supply passage 15c described above, and the other end of the gas supply pipe 41 is branched to supply the first gas supply source 42, the second gas supply source 43, and the third gas supply. The source 44 is connected. The first gas supply source 42 supplies the raw material gas, the second gas supply source 43 supplies the plasma excitation gas, and the third gas supply source 44 supplies the cleaning gas. On-off valves (not shown) for starting or stopping gas supply at positions corresponding to the first gas supply source 42, the second gas supply source 43, and the third gas supply source 44 in the gas supply pipe 41, respectively. ) And a flow rate adjustment mechanism (not shown) for adjusting the gas supply amount. The flow rate adjusting mechanism has, for example, a mass flow controller.

Returning to the description of FIG.
The image pickup apparatus 3 includes a hyperspectral camera 3a, a light source 3b, and a moving mechanism 3c.
The hyperspectral camera 3a is for generating an captured image showing the intensity of light for each of 10 or more wavelength bands (for example, 100 or more wavelength bands) included in the light based on the light from the imaging target. be. For example, the hyperspectral camera 3a decomposes light in the visible light region (400 to 750 nm) into 10 or more wavelength bands different from each other, and generates an captured image showing the intensity of light for each wavelength band.

The hyperspectral camera 3a images a portion (hereinafter, referred to as “low temperature portion”) in the processing container 10 including a low temperature surface that becomes lower than the upper surface (mounting surface) 20a of the mounting table 20 during the cleaning process. The low temperature surface is the back surface 20c of the mounting table 20 in this example. Since the back surface 20c of the mounting table 20 is separated from the heater 21 as compared with the upper surface 20a, the temperature is lower than that of the upper surface 20a.

The hyperspectral camera 3a has an imaging unit 3aa as a detection unit and a generation unit 3ab.
The image pickup unit 3aa is an element (wavelength filter, diffraction grating, etc.) that decomposes (spectralizes) the light from the low temperature portion, specifically, the reflected light reflected from the light source 3b in the low temperature portion into each wavelength band. It has an image sensor (for example, a CCD sensor or a CMOS sensor) in which light receiving elements that receive the decomposed light of each wavelength band are arranged. The image pickup unit 3aa has a moving mechanism of the image sensor when it is necessary to scan the image sensor.

The image pickup unit 3aa detects the light intensity for each of the 10 or more wavelength bands included in the light based on the light from the low temperature portion. Specifically, the image pickup unit 3aa decomposes light from each of the plurality of regions in the low temperature portion into 10 or more wavelength bands. Each of the above regions corresponds to each light receiving element included in the above-mentioned image sensor. Then, the image pickup unit 3aa receives the light of each wavelength band by the above-mentioned image sensor, and detects the light intensity for each wavelength band and for each of the above-mentioned regions in the low temperature portion.

The imaging timing of the imaging unit 3aa is controlled by the imaging control unit 4a described later, which is included in the control device 4.

The generation unit 3ab is realized by, for example, a microprocessor, a memory including a ROM or a RAM, or the like. The generation unit 3ab generates an image of a low temperature portion showing the distribution of the light intensity of the wavelength band for each wavelength band based on the detection result of the light intensity for each wavelength band by the imaging unit 3aa. More specifically, the captured image of the low temperature portion of each wavelength band shows the detection result of the light intensity of the corresponding wavelength band for each light receiving element of the image sensor, and the pixel value of the pixel at the position corresponding to the light receiving element. It is an image.

As shown in FIG. 3, the captured images I11 for each wavelength band generated by the generation unit 3ab are rectangular parallelepiped when arranged in the order of the lengths of the wavelength bands. Therefore, the captured images generated by the generation unit 3ab Group I1 is sometimes referred to as a data cube. In FIG. 3, the x-axis and the y-axis indicate the positions of the pixels of the captured image, and the λ-axis indicates the wavelength.

Returning to the description of FIG.
The light source 3b emits light in a wavelength band including a wavelength band received by the image pickup unit 3aa of the hyperspectral camera 3a. In this example, the light source 3b emits light in the visible light region (400 nm to 750 nm).
The light from the light source 3b illuminates the low temperature portion in the processing container 10 imaged by the hyperspectral camera 3a.

The light emission timing of the light source 3b is controlled by the imaging control unit 4a described later.

The moving mechanism 3c moves the imaging unit 3aa. The moving mechanism 3c allows the imaging unit 3aa to be aligned with the low temperature portion in the processing container 10 of the film forming apparatus 2. The moving mechanism 3c has, for example, a stage configured to be movable in the horizontal direction (XY direction) and the vertical direction. The moving mechanism 3c is fixed to the processing container 10 via a mounting member (not shown), for example.

The operation of the moving mechanism 3c for aligning the image pickup unit 3aa is controlled by, for example, the image pickup control unit 4a described later. However, the moving mechanism 3c may be manually operated by the operator.

The control device 4 controls the film forming device 2, controls the image pickup device 3, controls the display device 5, controls the printing device 6, and the like. The control device 4 is composed of, for example, a computer equipped with a CPU, a memory, a graphic board, and the like, and has a program storage unit (not shown). The program storage unit stores a program for realizing the processing of the wafer in the processing system 1. The program may be recorded on a storage medium readable by a computer and may be installed on the control device 4 from the storage medium. Further, a part or all of the program may be realized by dedicated hardware (circuit board).

The control device 4 includes an image pickup control unit 4a, a film formation control unit 4b, an image processing unit 4c, a display control unit 4d, a print control unit 4e, and a storage unit 4f.

The image pickup control unit 4a controls the image pickup device 3.

The film forming control unit 4b controls the film forming apparatus 2.

The image processing unit 4c processes the captured image of the low temperature portion for each wavelength band generated by the image pickup device 3. Specifically, the image processing unit 4c corresponds to the pixel value of each pixel with respect to the image captured in the low temperature portion for the wavelength band of interest, which will be described later, in the image group of the low temperature portion generated by the imaging device 3. A pseudo-color image is generated by performing the process of assigning the colors. The wavelength band of interest is a wavelength band corresponding to the reaction product generated during the film forming process and remaining in the processing container 10 after the film forming process.
The wavelength band of interest is set in advance, and the information is stored in the storage unit 4f. The wavelength band of interest may be set by the operator selecting the wavelength band. Further, a table showing the relationship between the processing conditions such as the film forming type and the wavelength band is stored in the storage unit 4f, and based on this table, the processing conditions such as the film forming species designated by the operator are met. The wavelength band of interest may be set.

Further, the wavelength band of interest may be one or a plurality.

The display control unit 4d controls the display device 5 to display various information. Under the control of the display control unit 4d, for example, a pseudo color image is displayed and output to the display device 5.

The print control unit 4e controls the printing device 6 to print various information. Under the control of the print control unit 4e, for example, the printing device 6 prints out a pseudo color image.

The storage unit 4f stores various information. For example, the storage unit 4f stores information on the wavelength band of interest, a group of captured images of a low temperature portion generated by the image pickup apparatus 3, a pseudo color image, and the like.

The display device 5 is a device that displays various types of information, and examples of such a device include a liquid crystal display device, a plasma display device, an EL display device, and the like.

The printing device 6 is a device that prints various types of information, and examples of such a device include a color laser printer, an inkjet printer, and the like.

Subsequently, an example of the flow of processing performed by using the processing system 1 will be described. FIG. 4 is a flowchart for explaining an example of the flow of processing performed by using the processing system 1. 5 and 6 are diagrams for explaining the generation process of the pseudo color image. Although the pseudo color images I2a and I6 and the composite images I3a, I4a and I5a in FIGS. 5 and 6 are shown in black and white in the drawings, they are actually color images.

First, as shown in FIG. 4, a film forming process is performed (step S1). Specifically, the wafer W is carried into the processing container 10 from the outside of the processing container 10 of the film forming apparatus 2 via the carry-in outlet 11a, and is placed on the upper surface 20a of the mounting table 20 via the support pin 26a. W is delivered. Next, the inside of the processing container 10 is adjusted to a predetermined pressure, the mounting table 20 is moved to the processing position by the elevating mechanism 23, the processing space S2 is formed, and the temperature of the wafer W is raised. When heated the wafer W via the susceptor 20 to the desired temperature (eg 300 ° C. to 600 ° C.), the processing space S2, for example, with SiH ₄ gas as a source gas from the first gas supply source 42 is supplied , For example, Ar gas is supplied as a plasma excitation gas from the second gas supply source 43. Further, high-frequency power is supplied from the high-frequency power supply 31 to the shower head 15 and from the high-frequency power supply 30 to the mounting table 20. As a result, Ar plasma is formed, SiH ₄ gas is decomposed by Ar plasma, and an amorphous silicon (a-Si) film is formed on the wafer W. After that, the wafer W is carried out from the processing container 10.

When the film forming process is completed, the cleaning process is started (step S2). Specifically, for example, NF ₃ gas is supplied as a cleaning gas and, for example, Ar gas is supplied as a plasma excitation gas into the processing container 10. Further, high-frequency power is supplied from the high-frequency power supply 31 to the shower head 15 and from the high-frequency power supply 30 to the mounting table 20. As a result, Ar plasma is formed and NF ₃ gas is decomposed to generate fluorine radicals. The reaction products adhering to the processing chamber 10 occurs during the film forming process may react with the fluorine radicals, become SiF ₄ gas is discharged from the processing chamber 10.

During the cleaning process, based on the light from a plurality of regions contained in the low temperature portion in the processing container 10, the light intensity is detected for each region for each of the 10 or more wavelength bands contained in the light (step S3). ). Specifically, under the control of the imaging control unit 4a, light in the visible light region is emitted from the light source 3b, and the light in the visible light region is emitted to a low temperature portion in the processing container 10 including the back surface 20c of the mounting table 20 through the optical window 19. Be irradiated. Further, under the control of the image pickup control unit 4a, the image pickup unit 3aa of the hyperspectral camera 3a obtains each of the 100 different wavelength bands in the visible light region based on the reflected light from each of the plurality of regions in the low temperature region. The reflected light intensity is detected. The detection result is output to the generation unit 3ab.
The temperature of the mounting table 20 during the cleaning process is substantially equal to that during the film forming process.
The detection of the reflected light intensity by the image pickup unit 3aa is performed, for example, every time a certain period of time elapses, for example, at a time when a predetermined time has elapsed from the start of the cleaning process, or after that point until the cleaning process is completed. It is done in. Further, the detection of the reflected light intensity by the image pickup unit 3aa may be performed when the operator receives an input of execution support during the cleaning process.

Subsequently, based on the detection result of the image pickup unit 3aa, an image of the low temperature portion is generated for each of the above 10 or more wavelength bands (step S4). Specifically, the generation unit 3ab generates an image of a low temperature portion for each of 100 different wavelength bands in the visible light region based on the detection result of the image pickup unit 3aa. The generated image group of the captured image of the low temperature portion is output to the control device 4 and stored in the storage unit 4f.

Next, among the image group of the low temperature part generated by the image pickup unit 3aa, the image of the low temperature part in the wavelength band of interest is subjected to a process of assigning a color according to the pixel value to each pixel, and a pseudo color image is obtained. Is generated (step S5).

Here, it is assumed that there is one wavelength band of interest, which is the wavelength band a. In step S5, for example, as shown in FIG. 5, the captured image I2 of the low temperature portion of the wavelength band a of the captured image group I1 of the low temperature portion composed of the captured images of each of the 100 wavelength bands is image-processed. Obtained from the storage unit 4f by the unit 4c. Then, the image processing unit 4c makes each pixel have an R (red) color corresponding to the pixel value (corresponding to the light intensity of the reflected light in the wavelength band a) with respect to the captured image I2 in the low temperature portion of the wavelength band a. A process of assigning an R value, which is color information in space, is performed. As a result, a pseudo color image I2a for the wavelength band a, which shows the distribution of the reflected light intensity in the wavelength band a with shades of red, is generated. The color information is information for determining a color, and includes, for example, information on the type of primary color and information on luminance.

The wavelength band of interest may be plural as described above. In this case, the image processing unit 4c assigns a color corresponding to the wavelength band of interest and the pixel value to each pixel of the captured image of the low temperature portion for each of the plurality of wavelength bands of interest, and generates an image for compositing. Composite images for each of the plurality of wavelength bands of interest are combined to generate a pseudo-color image.
For example, assume that there are three wavelength bands of interest, which are wavelength bands b, c, and d. In this case, for example, the processing is performed as follows. That is, as shown in FIG. 6, in the captured image group I1 of the low temperature portion, the captured image I3 of the low temperature portion of the wavelength band b, the captured image I4 of the low temperature portion of the wavelength band c, and the captured image of the low temperature portion of the wavelength band d. I5 is acquired from the storage unit 4f by the image processing unit 4c. Next, the image processing unit 4c makes each pixel have an R (red) color corresponding to the pixel value (corresponding to the light intensity of the reflected light in the wavelength band b) with respect to the captured image I3 in the low temperature portion of the wavelength band b. A process of assigning an R value, which is color information in space, is performed. As a result, a composite image I3a for the wavelength band b, which shows the distribution of the reflected light intensity in the wavelength band b with shades of red, is generated. Further, the image processing unit 4c has a G (green) color corresponding to the pixel value (corresponding to the light intensity of the reflected light in the wavelength band c) for each pixel with respect to the captured image I4 in the low temperature portion of the wavelength band c. A process of assigning a G value, which is color information in space, is performed. As a result, a composite image I4a for the wavelength band c, which shows the distribution of the reflected light intensity in the wavelength band c with shades of green, is generated. Further, the image processing unit 4c makes a B (blue) color corresponding to the pixel value (corresponding to the light intensity of the reflected light in the wavelength band d) for each pixel with respect to the captured image I5 in the low temperature portion of the wavelength band d. A process of assigning a B value, which is color information in space, is performed. As a result, a composite image I5a for the wavelength band c, which shows the distribution of the reflected light intensity in the wavelength band b with shades of blue, is generated. Then, the image processing unit 4c synthesizes the composite images I3a, I4a, and I5a, and generates a pseudo color image I6 showing the distribution of the reflected light intensity in the wavelength bands b, c, and d in RGB.

In the above example, the color information in the RGB color space is assigned, but the color information in other color spaces such as RGBA, CMY, CMYK, HSV, and HLS may be assigned.
Further, an image corresponding to an image captured by an RGB camera, such as a normal RGB image, may be combined with the pseudo color image.
Information indicating the correspondence between the pixel value of the captured image in the low temperature portion and the color information assigned to the pixel value is stored in advance in the storage unit 4f.

When the pseudo-color image is generated, the pseudo-color image is output (step S6). For example, the display control unit 4d displays the pseudo color image I2a (or the pseudo color image I6) on the display device 5. The print control unit 4e may print the pseudo color image I2a (or the pseudo color image I6) from the printing device 6.

Subsequently, it is determined whether or not to end the cleaning process based on the output pseudo-color image (step S7). For example, based on the display result and the print result of the pseudo color image I2a (or the pseudo color image I6), the operator determines whether or not to end the cleaning process. For example, if the position corresponding to the back surface 20c of the mounting table 20 in the pseudo color image I2a (or the pseudo color image I6) is not colored with a specific color, the reaction product is removed from the back surface 20c of the mounting table 20. Therefore, the operator determines that the cleaning process is completed. Since the reaction product is most likely to remain on the back surface 20c of the mounting table 20 which is a low temperature surface in the processing container 10, if the reaction product is removed from the back surface 20c of the mounting table 20, the cleaning process is completed at that point. However, no reaction product remains in other parts of the processing vessel 10.

If it is determined that the process does not end (NO), the process returns to step S3.
On the other hand, when it is determined that the process is completed (YES), the cleaning process is completed (step S8). Specifically, when it is determined that the cleaning process is completed, an instruction to end the cleaning process is input from the operator via an input means (not shown) such as a keyboard or a mouse of the control device 4. The cleaning process is stopped according to the input. The cleaning process stop process is, for example, a process of stopping the supply of cleaning gas, plasma excitation gas, and high-frequency power.
After that, the above-mentioned processes of steps S1 to S8 are performed on the next wafer W.

As described above, the processing system 1 including the end point determination device according to the present embodiment has light intensity for each of the 10 or more wavelength bands included in the light based on the light from the low temperature surface in the processing container 10. Is included in the generation unit 3ab that generates an image of a low-temperature surface and the wavelength bands of 10 or more for each of the 10 or more wavelength bands based on the detection results of the image pickup unit 3aa and the image pickup unit 3aa. It has an image processing unit 4c that generates a pseudo-color image by assigning a color corresponding to the pixel value to each pixel of the captured image on the low temperature surface in the wavelength band of interest corresponding to the reaction product.
The pseudo-color image generated as described above shows in color the detection result of light in the wavelength band of interest corresponding to the reaction product on the low temperature surface where the reaction product is most likely to remain. Therefore, according to the present embodiment, even an operator with a low skill level can accurately determine the end point of the cleaning process based on the pseudo-color image. Further, even an operator with a low skill level can determine at a glance whether or not the reaction product remains from the pseudo color image, so that the end point of the cleaning process can be determined in a short time. According to the present embodiment. Since the end point of the cleaning process can be accurately determined, the remaining reaction products do not become particles and affect the substrate process such as the film formation process, so that the yield can be prevented and the quality such as film quality can be improved. It can be prevented from decreasing. Further, since the end point of the cleaning process can be accurately determined, the time required for the cleaning process can be shortened as much as possible within the range where no reaction product remains. Therefore, productivity is improved.
Further, according to the present embodiment, when determining the end point of the cleaning process, it is not necessary to open the processing container 10 to the atmosphere, so that the throughput does not decrease.
In addition, the presence of particles reduces quality. Since there is no residual film, it can be obtained at a high quality position. Constant in high quality. The number of bad dots is reduced. Yield is improved.

Further, since the pseudo color image corresponds to the captured image of the low temperature surface, when the reaction product remains, the operator can easily determine the position where the reaction product remains based on the pseudo color image. be able to.
Further, since the operator can discriminate the portion where the reaction product is likely to remain from the pseudo color image, the discriminating result can be reflected in the processing conditions of the cleaning process, the structural design of the film forming apparatus 2, etc., and the result can be reflected. , The time required for the cleaning process can be shortened.

Further, in the present embodiment, a plurality of attention wavelength bands are set, and colors corresponding to the attention wavelength band and the pixel value are assigned to each pixel for the captured image of the low temperature portion for each of the plurality of attention wavelength bands, and the composite image is used. Is generated, the generated composite image is composited, and a pseudo-color image is generated. Therefore, even when a plurality of types of reaction products are present, the end point of the cleaning process can be accurately determined based on the pseudo-color image.

(Second Embodiment)
FIG. 7 is an explanatory diagram schematically showing an outline of the configuration of a processing system including the end point determination device according to the second embodiment.
In the processing system 1a according to the present embodiment, in addition to the configuration of the processing system 1 according to the first embodiment, the control device 4 has a determination unit 4g.
In this embodiment, for example, the detection result of the imaging unit 3aa for the wavelength band of interest is output to the control device 4. Then, the determination unit 4g determines the end point of the cleaning process based on the detection result of the imaging unit 3aa for the wavelength band of interest.
The detection results for all wavelength bands detected by the imaging unit 3aa are output to the control device 4 and stored in the storage unit 4f, from which the determination unit 4g detects the detection results for the wavelength band of interest. May be extracted and the end point of the cleaning process may be determined based on the extraction result.

According to this embodiment, the end point of the accurate cleaning process can be automatically determined.
Further, in the present embodiment, it is possible to output a pseudo color image while automatically determining the end point of the cleaning process based on the detection result of the imaging unit 3aa. Therefore, as in the first embodiment, the operator can discriminate the portion where the reaction product is likely to remain from the pseudo color image, and the discriminating result can be used for the processing conditions of the cleaning process, the structural design of the film forming apparatus 2, and the like. It can be reflected, and as a result, the time required for the cleaning process can be shortened.

Further, in the present embodiment, the operator determines the end point of the cleaning process based on the pseudo-color image, and the determination unit 4g automatically determines the end point of the cleaning process based on the detection result of the imaging unit 3aa for the wavelength band of interest. You can switch between the method of determining with and.

(Reference embodiment)
FIG. 8 is an explanatory diagram schematically showing an outline of a configuration of a processing system including an end point determination device according to a reference embodiment.
The processing system 100 according to the present embodiment is obtained by removing the image processing unit 4c from the processing system 1a according to the second embodiment.
Although the processing system 100 does not generate a pseudo-color image, the determination unit 4g can accurately determine the end point of the cleaning process based on the detection result of the imaging unit 3aa for the wavelength band of interest.

In the above, the low temperature surface was the back surface 20c of the mounting table 20, but instead of or in addition to this, the side peripheral surface of the mounting table 20 and the vicinity of the gap in the inner wall surface of the processing container 10. You may.

Further, in the above, the hyperspectral camera 3a has a generation unit 3ab. Instead of this, the control device 4 may have a generation unit 3ab.

In the above, the detection unit that detects the light intensity for each wavelength band is assumed to be the image pickup unit 3aa of the hyperspectral camera 3a, but the present invention is not limited to this, and elements such as filters and diffraction gratings that decompose light and an image sensor are used. A plurality of sets of and may be combined to form the detection unit. Further, the detection unit that detects the light intensity for each wavelength band may be an imaging unit of a multispectral camera. In the present specification, the hyperspectral camera means a camera having 16 or more wavelength bands capable of detecting light intensity, and the multispectral camera has 3 or more and 15 wavelength bands. Refers to the following.
The image pickup unit 3aa and the light source 3b may be separate or integrated.

In the above, the mounting table 20 does not rotate, but the mounting table 20 may be configured to be rotatable.
In this case, the captured image of the back surface 20c of the mounting table 20 may be acquired for each wavelength band while rotating the mounting table 20. As a result, it is possible to determine whether or not the reaction product remains on the entire back surface 20c of the mounting table 20, so that the end point of the cleaning process can be made more accurate.

In the above, the image pickup unit 3aa can detect the light in the visible light region, and the light source 3b emits the light in the visible light region. The detectable wavelength band of the image pickup unit 3aa and the band of light emitted by the light source 3b are not limited to the visible light region, and may be, for example, an infrared region or an ultraviolet region.

In the above, the a-Si film was formed, but the technique according to the present disclosure can also be applied to the formation of other film types.

In the above, a processing system including a film forming apparatus has been described as an example, but the technique according to the present disclosure is a film forming apparatus as long as it is a substrate processing apparatus that heats a substrate via a mounting table having a built-in heater during substrate processing. It can also be applied to other than. For example, it can also be applied to doping devices.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The above embodiments may be omitted, replaced or modified in various forms without departing from the scope of the appended claims and their gist.

2 Film formation device 3aa Image pickup unit 3ab Generation unit 4c Image processing unit 10 Processing container 20a Upper surface (mounting surface) of mounting table
20c Back side of mounting table I2 Captured image I2a Pseudo-color image I3 Captured image I4 Captured image I5 Captured image I6 Pseudo-color image I11 Captured image W wafer

Claims (9)

An end point determination device for determining the end point of the removal process.
The removal process is a process for removing the reaction product remaining in the processing container of the substrate processing apparatus after the substrate is processed on the substrate in the substrate processing apparatus.
The end point determination device is
A detection unit that detects light intensity for each of the 10 or more wavelength bands contained in the light based on the light from a low temperature surface that is lower than the surface on which the substrate is placed during the removal treatment in the processing container. When,
Based on the detection result of the detection unit, for each of the 10 or more wavelength bands, a generation unit that generates an image of the low temperature surface showing the distribution of light intensity in the wavelength band, and a generation unit.
Image processing for generating a pseudo-color image by assigning a color corresponding to a pixel value to each pixel of the image captured on the low temperature surface for the wavelength band corresponding to the reaction product contained in the 10 or more wavelength bands. A device for determining the end point, which comprises a unit and a unit. The end point determination device according to claim 1, further comprising a determination unit for determining the end point of the removal process based on the detection result of the detection unit for the wavelength band corresponding to the reaction product. The end point determination device according to claim 1 or 2, wherein the detection unit is an imaging unit of a hyperspectral camera or a multispectral camera. The image processing unit generates a composite image by assigning a color corresponding to the wavelength band and the pixel value to each pixel in the captured image of the low temperature surface for each of the plurality of wavelength bands corresponding to the reaction product. The end point determination device according to any one of claims 1 to 3, wherein the composite image for each of the plurality of wavelength bands is synthesized to generate the pseudo color image. The low temperature surface includes at least one of a surface of the mounting table on which the substrate is mounted, a surface opposite to the surface on which the substrate is mounted, a side surface of the above-mentioned stand, and an inner peripheral surface of the processing container. The end point determination device according to any one of claims 1 to 4. It has a light source that illuminates the low temperature surface.
The end point determination device according to any one of claims 1 to 5, wherein the light from the low temperature surface is reflected light of light from the light source. The end point determination device according to any one of claims 1 to 6, wherein the wavelength band corresponding to the reaction product is predetermined. The end point determination device according to any one of claims 1 to 7, wherein the substrate processing is performed while heating the substrate through a surface on which the substrate is placed. It is an end point determination method for determining the end point of the removal process.
The removal process is a process for removing the reaction product remaining in the processing container of the substrate processing apparatus after the substrate is processed on the substrate in the substrate processing apparatus.
The end point determination method is
A step of detecting the light intensity for each of the 10 or more wavelength bands contained in the light based on the light from the low temperature surface in the processing container, which is lower than the surface on which the substrate is placed during the removal treatment. ,
Based on the detection result in the detection step, for each of the 10 or more wavelength bands, a step of generating an image of the low temperature surface showing the distribution of light intensity in the wavelength band, and a step of generating an image.
A step of generating a pseudo-color image by assigning a color corresponding to a pixel value to each pixel of the image captured on the low temperature surface for the wavelength band corresponding to the reaction product contained in the 10 or more wavelength bands. ,
A method for determining an end point, which comprises a step of determining an end point of the removal process based on the pseudo-color image.

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