Plasma processing apparatus and plasma processing method

Abstract

Provided are a plasma processing apparatus and a plasma processing method capable of measuring reflected light reflected by a processing target region without depending on a pattern layout of a device. The plasma processing apparatus includes: a light irradiation unit including a plurality of irradiators that irradiate light to different positions on a surface of a wafer placed on a sample stage; a light receiving unit that receives reflected light obtained by reflecting the light irradiated from the plurality of irradiators by the wafer; and a processing amount detection unit that detects the processing amount of the wafer on the basis of information obtained from the reflected light received by the light receiving unit during the processing of the wafer, the processing amount detection unit detects the processing amount of the wafer on the basis of the difference between information of each reflection position of the wafer reflecting the light irradiated from each of the plurality of irradiators and information of the processing position of the wafer, and the difference between the information of each reflection position of the wafer reflecting the light irradiated from each of the plurality of irradiators and the information of the processing position of the wafer. The processing amount of the wafer is detected by determining the irradiator for light irradiation from among the plurality of irradiators, and using the determined irradiator.

Description

Technical Field

[0001] The technology disclosed herein relates to a plasma processing apparatus and a plasma processing method using the same. Background Art

[0002] A semiconductor device has various components on the surface of a wafer, wirings connecting them to each other, etc. Such a semiconductor device is formed by repeatedly forming films of various materials such as conductors, semiconductors, and insulators and removing unnecessary parts.

[0003] As a process for removing unnecessary parts, dry etching using plasma is widely used. In plasma etching, gas introduced into a processing chamber of an etching device is plasmatized by a high-frequency power supply or the like, and etching is performed by exposing a wafer to the plasmatized gas.

[0004] Anisotropic etching and isotropic etching are performed by sputtering of ions in plasma, chemical reaction of radicals, etc. By using these etching methods separately, components and wirings of various structures can be formed on the surface of the wafer.

[0005] When the processed shape of a wafer by plasma etching is different from the design, various components formed cannot fulfill their functions. Therefore, many technologies related to process monitors for monitoring and stabilizing the etching process of a wafer have been proposed.

[0006] For example, a process monitor that measures the thickness of a film formed on a wafer and the depth of a groove or hole formed on a wafer by measuring reflected light from a wafer during etching is also called a film thickness / depth monitor, and is used in determining the end point of etching, etc. In addition, hereinafter, the film thickness / depth monitor is omitted and referred to as a film thickness monitor.

[0007] Patent Document 1 describes a method for improving machining accuracy using a film thickness monitor. More specifically, Patent Document 1 describes a method for detecting the timing before the film to be processed is completely removed by using a film thickness measuring device equivalent to a thick film monitor using plasma light as a light source, thereby ending the etching process, and then switching to a condition for highly selectively etching the process target portion and the process non-target portion to perform the etching process.

[0008] In addition, a technique for improving the film thickness / depth measurement accuracy of a film thickness monitor is described in Patent Document 2. More specifically, Patent Document 2 describes that by using an external light source as a light source for irradiating a wafer instead of plasma light, light source fluctuations of the light source are reduced, and high-precision film thickness / depth measurement can be achieved.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Publication No. 2006-119145

[0012] Patent Document 2: JP 2004-507070 Summary of the invention

[0013] Problems to be solved by the invention

[0014] However, in the manufacture of semiconductor devices, electronic circuits, wiring parts, and boundary lines between devices that perform various functions are formed on the chip in a specific layout to produce devices that realize the desired functions. For example, in the memory device, there are memory parts that are responsible for data storage, circuit parts that implement the storage / deletion of data in these memories, etc. In addition, in the logic device, there are operation parts that are responsible for the calculation of digital data, memory parts that temporarily store the calculation results, etc. The layout of the parts that form these electronic circuits and the boundary lines of the devices varies depending on the device. In addition, from now on, the layout on these chips will be collectively referred to as pattern layout.

[0015] Since there are various pattern layouts, in the manufacturing process of the device, in order to perform endpoint determination by the film thickness monitor and realize high-precision processing, it is preferable to measure the reflected light reflected from the processing target area being processed in the process. For example, in the memory cell formation process in the memory device, it is preferable to obtain the reflected light of the processing target area, that is, the memory cell part, rather than the boundary part of the device or the circuit part for data recording / deletion.

[0016] Here, the film thickness monitor irradiates light from an external light source to the wafer via a light irradiation port (also called an irradiator), and measures the reflected light received via a light measurement port (also called a light receiving unit). In such a film thickness monitor, when the positions of the light irradiation port and the light measurement port are fixed, the position on the wafer where the reflected light is measured is uniquely determined and becomes a fixed position. Specifically, the position where the perpendicular bisector of the line segment connecting the two ports intersects with the wafer becomes the center of the monitor position where the reflected light is measured.

[0017] When using a film thickness monitor in which the positions of the light irradiation port and the light measurement port are fixed in this way, it is difficult to always measure the reflected light reflected from the processing target area of ​​the wafer in the manufacturing process of devices with various pattern layouts. Therefore, depending on the pattern layout of the device on the wafer, the film thickness / depth measurement accuracy of the film thickness monitor on the wafer will decrease, and it may be difficult to perform endpoint determination using the film thickness monitor with high accuracy.

[0018] The technology disclosed in the present invention has been proposed in view of such a situation, and an object of the present invention is to provide a plasma processing apparatus and a plasma processing method capable of measuring reflected light reflected from a processing target region without depending on a pattern layout of a device.

[0019] Means for solving problems

[0020] As a representative technology among the technologies disclosed in the present invention, a plasma processing device includes: a processing chamber inside a vacuum container; and a sample stage, which is arranged in the processing chamber and has a processing object, i.e., a wafer, placed on the upper surface. The plasma processing device includes: a light irradiation unit, which has a plurality of irradiators for irradiating light to different positions on the surface of the wafer placed on the sample stage; a light receiving unit, which receives reflected light obtained by reflecting the light irradiated from the plurality of irradiators by the wafer; and a processing amount detection unit, which detects the processing amount of the wafer based on information obtained from the reflected light received by the light receiving unit during the processing of the wafer, the processing amount detection unit determines an irradiator for light irradiation from among the plurality of irradiators based on the difference between information on each reflection position of the wafer that reflects the light irradiated from the plurality of irradiators and information on the processing position of the wafer, and uses the determined irradiator to detect the processing amount of the wafer.

[0021] Effects of the Invention

[0022] If the effects obtained by the representative technology among the technologies disclosed in the present invention are briefly described, they are as follows. According to the technology disclosed in the present invention, the reflected light from the processing object area can be always measured without relying on the pattern layout of the wafer. As a result, high-precision film thickness measurement and endpoint determination can be achieved. Furthermore, high-precision processing of the device can be achieved. The topics, structures and effects other than the above-mentioned are clarified by the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a diagram showing the overall structure of the plasma processing apparatus according to the first embodiment.

[0024] Figure 2 This is a diagram showing a schematic structure of a wafer processor according to the first embodiment.

[0025] Figure 3 This is a diagram schematically showing the structure of the optical system involved in Embodiment 1.

[0026] Figure 4 This is a diagram schematically showing an example of a pattern layout of a wafer in the first embodiment.

[0027] Figure 5 This is a diagram showing the functional blocks of the processing amount calculation unit involved in the first embodiment.

[0028] Fig. 6A This is a diagram showing the spectrum of reflected light from the electronic circuit portion of the wafer in the first embodiment.

[0029] Figure 6B This is a diagram showing the spectrum of reflected light from the peripheral portion of the wafer in the first embodiment.

[0030] Figure 7 This is a diagram schematically showing the positional relationship between the light irradiation unit and the light receiving unit according to the second embodiment.

[0031] Figure 8 This is a diagram showing the processing position of the wafer and the monitor position in the second embodiment.

[0032] Fig. 9 This is a diagram schematically showing the positional relationship between a light irradiation unit and a light receiving unit according to the third embodiment.

[0033] Fig.10 This is a diagram schematically showing an example of a wafer processing position and a monitor position in the third embodiment.

[0034] Fig.11 This is a diagram showing the spectrum of reflected light obtained by test irradiation in the fourth embodiment.

[0035] Fig.12 This is a diagram showing an example of calculation results of error values ​​between the spectrum of reflected light at each monitor position and the reference spectrum in the sixth embodiment. DETAILED DESCRIPTION

[0036] Hereinafter, the embodiments of the technology disclosed in the present invention will be described in detail with reference to the accompanying drawings. In addition, in the accompanying drawings, the same reference numerals are generally given to the same parts, and repeated descriptions are omitted. In the accompanying drawings, in order to make the invention easier to understand and compared with the actual method, the width, thickness, shape, etc. of each part are sometimes schematically represented, but this is only an example and does not limit the interpretation of the present invention.

[0037] (Implementation method 1)

[0038] Figure 1 This is a diagram schematically showing the overall structure of the plasma processing apparatus according to the first embodiment. Figure 2 This is a diagram showing a schematic structure of a wafer processor according to the first embodiment. Figure 3 This is a diagram schematically showing the structure of the optical system involved in Embodiment 1.

[0039] like Figure 1As shown, the plasma processing apparatus 100 according to the present embodiment includes: a wafer processor 200 for performing etching processing (plasma processing) on ​​a wafer 500 as a processing target; and a processing amount measuring device 300 for measuring a processing amount (etching amount) of the wafer 500 by the wafer processor 200 .

[0040] <Chip Processor>

[0041] First, the schematic structure of the wafer processor 200 is described. As an example, the wafer processor 200 involved in this embodiment uses the electric field of microwaves as the electric field for forming plasma, causes ECR (Electron Cyclotron Resonance) of the electric field and magnetic field of microwaves to form plasma, and uses the plasma to etch a processing object such as a semiconductor wafer (hereinafter simply referred to as a wafer). That is, the wafer processor 200 can also be called a plasma etching device.

[0042] like Figure 2 As shown, the wafer processor 200 has a container, for example, a vacuum container 205, having a processing chamber 203 in which plasma 201 is formed. In the processing chamber 203, below the space in which the plasma 201 is formed, a sample stage 207 is arranged on which a wafer 500 to be processed is placed.

[0043] The upper part of the processing chamber 203 is blocked by, for example, a disc-shaped dielectric window member 209. Below the window member 209, a shower plate 211 constituting a circular ceiling surface of the processing chamber 203 is provided. The shower plate 211 has a disc shape having a plurality of gas introduction holes 211a arranged through the center portion, and a gas for etching processing is introduced into the processing chamber 203 through the gas introduction holes 211a.

[0044] An exhaust port 213 connected to the processing chamber 203 is provided at the bottom of the vacuum container 205. In addition, a vacuum pump 215 such as a turbomolecular pump for exhausting the gas in the processing chamber 203 to reduce the pressure is provided below the processing chamber 203, and an exhaust volume regulating valve 217 for increasing or decreasing the area of ​​the flow path to adjust the flow rate or speed of the exhaust is provided.

[0045] An electric field / magnetic field forming unit 219 for forming an electric field and a magnetic field for generating plasma 201 in the processing chamber 203 is arranged above the vacuum container 205. The electric field / magnetic field forming unit 219 includes a waveguide 221 and an electric field generating power supply 223. The high-frequency electric field oscillated from the electric field generating power supply 223 is transmitted inside the waveguide 221 and introduced into the processing chamber 203.

[0046] Magnetic field generating coils 225 are disposed around the lower end of the waveguide 221 and around the vacuum container 205. The magnetic field generating coils 225 are composed of an electromagnet and a yoke that generate a magnetic field when a direct current is supplied.

[0047] In the wafer processor 200 having such a structure, microwaves are oscillated by the electric field generating power supply 223 while the processing gas is introduced into the processing chamber 203 from the gas inlet hole 211a of the shower plate 211. The electric field of the microwaves is supplied downward from the top to the processing chamber 203 through the window member 209 and the shower plate 211. Furthermore, the magnetic field caused by the direct current supplied to the magnetic field generating coil 225 is supplied to the processing chamber 203, and interacts with the electric field of the microwaves to cause ECR. Through this ECR, the atoms or molecules of the processing gas are excited, dissociated or ionized, and a high-density plasma 201 is generated in the processing chamber 203. Then, the semiconductor wafer 500 set on the sample stage 207 is etched (plasma processing) by the plasma 201.

[0048] <Overall Control Section>

[0049] In addition, if Figure 1 As shown, the plasma processing apparatus 100 includes an overall control unit 150 that comprehensively controls the operation of the plasma processing apparatus 100 .

[0050] The overall control unit 150 is composed of, for example, a computing unit such as a CPU (Central Processing Unit), a RAM (Random Access Memory) unit such as a semiconductor memory, a storage unit such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive), a communication unit, etc. In addition, the overall control unit 150 may use an ASIC (Application Specific Integrated Circuit) or a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) instead of a CPU.

[0051] The overall control unit 150 controls the operation of the wafer processor 200, which is a plasma etching device, as one of the controls of the plasma processing device 100. The overall control unit 150, for example, performs the introduction of gas into the processing chamber 203, the generation and control of the plasma 201, and the application of voltage to the wafer 500 by a high-frequency power supply (not shown). In other words, the overall control unit 150 performs synchronization / timing adjustment between various devices, so that the desired etching process on the wafer 500 is achieved in the processing chamber 203.

[0052] Furthermore, when the plasma 201 is pulsed, the control of the pulse is also performed by the overall control unit 150. At this time, the voltage application, microwave irradiation, etc. performed by the high-frequency power supply for plasma-forming the etching gas are modulated, and their On / Off are switched to pulse the plasma 201. In addition, the plasma 201 is also pulsed by modulating the introduction time of the etching gas.

[0053] <Processing volume measuring device>

[0054] Furthermore, as described above, the plasma processing apparatus 100 includes a processing amount measuring device 300 for measuring the processing amount (etching amount) of the wafer 500 by the wafer processor 200. The processing amount measuring device 300 may also be referred to as a so-called film thickness monitor for measuring the thickness of a film formed on the wafer 500 and the depth of a groove or a hole formed on the wafer 500.

[0055] The processing amount measuring device 300 includes a light source unit 310, an optical system 320, and a detection unit 330. In addition, as an example, the light source unit 310, the optical system 320, and the detection unit 330 are arranged in the space between the waveguide 221 and the window member 209 of the wafer processor 200, that is, in the cavity 227. For example, the optical system 320 is arranged on the window member 209.

[0056] The light source unit 310 emits continuous light from ultraviolet to infrared. When the processing amount measuring device 300 uses a specific wavelength to measure the processing amount, in other words, to measure the film thickness / depth, the light source unit 310 may emit a light source of a specific wavelength.

[0057] The light emitted from the light source unit 310 is introduced into the processing chamber 203 via the optical system 320 , and is irradiated onto the semiconductor wafer 500 as irradiation light 311 .

[0058] More specifically, if Figure 3 As shown, the optical system 320 includes a light irradiation unit (also called a multi-point irradiation port) 321. The light irradiation unit 321 includes a plurality of irradiators (also called irradiation optical ports) 323 for irradiating the processing chamber 203 with light emitted from the light source unit 310 as irradiation light 311.

[0059] Furthermore, the plurality of irradiators 323 are disposed above the processing chamber 203 (eg, in the cavity 227) as described above, and are disposed at different positions in the in-plane direction of the wafer 500. As an example, the plurality of irradiators 323 are arranged in a row in the radial direction of the wafer 500.

[0060] Although not shown in the figure, each irradiator 323 is composed of a collimator lens and an optical fiber connecting the collimator lens and the light source unit 310. When the irradiation light 311 is irradiated to the wafer 500, the light emitted by the light source unit 310 is introduced into one or more specific optical fibers. Thus, the irradiation light 311 is irradiated to the wafer 500 via one or more irradiators 323.

[0061] The optical input from the light source unit 310 to each irradiator 323 is switched by an optical fiber switch (not shown). The structure of the irradiator 323 is not particularly limited as long as it can irradiate the wafer 500 in the processing chamber 203 with the light emitted from the light source unit 310 as the irradiation light 311.

[0062] In addition, in this embodiment, the example in which the plurality of irradiators 323 are arranged linearly on a plane parallel to the wafer 500 is described, but the arrangement of the irradiators 323 is not limited thereto. The irradiators 323 may be arranged, for example, in a two-dimensional plane or in a three-dimensional space above the wafer 500.

[0063] Furthermore, the optical system 320 includes at least one light receiving unit (light receiving port) 325 for inputting the reflected light 312 reflected by the wafer 500 to the detection unit 330. In the present embodiment, the optical system 320 includes one light receiving unit 325. Although not shown in the figure, the light receiving unit 325 is composed of a collimating lens and an optical fiber connecting the collimating lens and the detection unit 330.

[0064] In addition, the optical system 320 may include a plurality of light receiving units 325. In this case, each light receiving unit 325 is configured to include a collimating lens and an optical fiber. In addition, in the detection of the reflected light 312 from the wafer 500, the light received by a specific light receiving unit 325 is input to the detection unit 330. That is, the light from the specific optical fiber constituting the light receiving unit 325 is input to the detection unit 330.

[0065] Here, the reflected light 312 detected by the detection unit 330 is light reflected with the position where the perpendicular bisector of the straight line connecting the irradiator 323 for irradiating light and the light receiving unit 325 connected to the detection unit 330 intersects with the wafer 500. The reflection position on the wafer 500 of the reflected light 312 input to the light receiving unit 325 is referred to as a "monitor position".

[0066] In addition, in this embodiment, the processing amount measuring device 300 is illustrated as having a structure with a light source unit 310 and an optical system 320 that are independent of each other, but the structure of the processing amount measuring device 300 is not limited to this. In the processing amount measuring device 300, the light source unit 310 can be integrated with the optical system 320. For example, it is also possible to set a structure in which each irradiator 323 provided in the optical system 320 is provided with an LED that serves as a light source. In this case, in the processing amount measuring device 300, the light source unit 310 becomes a structure included in the optical system 320.

[0067] Furthermore, in order to efficiently irradiate the wafer 500 with the irradiation light 311 , each irradiator 323 may be configured as a combination of an LED and a collimator lens.

[0068] Furthermore, the processing amount measuring device 300 may include, for example, a display-type light source having a specific size and number of pixels as the light irradiation unit 321. In this case, the light source unit 310 is also included in the optical system 320.

[0069] The detection unit 330 includes, for example, a spectrometer, which splits the introduced light and detects the light quantity of each wavelength. When the processing amount of the wafer 500 (film thickness / depth on the wafer 500) is measured using a specific wavelength, the detection unit 330 is not limited to a spectrometer, and may also be a structure including a photodetector or the like.

[0070] In this case, if the light introduced into the detection unit 330 is only the desired specific wavelength, the detection unit 330 may be composed of only the photodetector. In addition, when continuous light is introduced, the detection unit 330 has a device such as a monochromator that selects only the specific wavelength in the front stage of the photodetector.

[0071] The detection of light by the detection unit 330 is continuously performed at a certain interval, for example, 2 Hz, 10 Hz, etc. during the plasma processing of the wafer 500 . Then, the detection data detected by the detection unit 330 is sent to the processing amount detection unit 340 .

[0072] The processing amount detection unit 340 is similar to the overall control unit 150, and is composed of a computing unit such as a CPU, a RAM unit, a storage unit, a communication unit, etc., and performs calculation of the processing amount (etching amount) of the wafer 500. In this embodiment, the processing amount detection unit 340 includes a processing position information acquisition unit 341, an optical system condition determination unit 343, and a processing amount calculation unit 345.

[0073] The processing position information acquisition unit 341 acquires information (hereinafter also referred to as processing position information) related to the processing position (also referred to as processing position) of the processing target wafer 500. As an example, the processing position information acquisition unit 341 acquires the processing position information of the wafer 500 from a processing information management unit (not shown) before etching processing.

[0074] Here, the information related to the processing position of the wafer 500 is, for example, information such as the coordinates of the processing position in the pattern layout of the wafer 500 or the coordinates that specify the processing target area including the processing position.

[0075] Figure 4 FIG. 1 is a diagram schematically showing an example of a pattern layout of a wafer in Embodiment 1. Figure 4 As shown, the wafer 500 to be processed has a single pattern 505 as a pattern layout, wherein the single pattern 505 includes an electronic circuit portion 501 and its peripheral portion 503. The single pattern 505 is repeatedly present on the wafer 500.

[0076] As an example, the size of the electronic circuit portion 501 is about 5 mm in length and 15 mm in width. In addition, the size of the individual pattern 505, that is, the size to the boundary between adjacent individual patterns 505, is about 30 mm in length and 30 mm in width.

[0077] In the individual pattern 505 of the wafer 500, the electronic circuit portion 501 is etched. Figure 4 In the example shown, the electronic circuit portion 501 becomes a processing position or a processing target area.

[0078] Therefore, the information supplied from the processing position information acquisition unit 341 to the optical system condition determination unit 343 is the coordinates of the processing position in the electronic circuit unit 501. The processing position information acquisition unit 341 supplies information on the coordinates of the processing positions P11 to P14 in each electronic circuit unit 501 to the optical system condition determination unit 343, for example.

[0079] The processing positions P11 to P14 can be set at any positions in the electronic circuit portion 501 , but are preferably set near the center of the electronic circuit portion 501 , for example.

[0080] The information acquired by the processing position information acquisition unit 341 is supplied to the optical system condition determination unit 343 . The optical system condition determination unit 343 determines the conditions of the optical system 320 based on the processing position information on the wafer 500 supplied from the processing position information acquisition unit 341 .

[0081] As one of the conditions of the optical system 320, the optical system condition determination unit 343 determines an irradiator 323 for light irradiation from among the multiple irradiators 323 based on the difference between the information of each reflection position (monitor position) of the chip 500 that reflects the light irradiated from the multiple irradiators 323 and the information of the processing position of the chip 500, and uses the determined irradiator 323 to detect the processing volume of the chip 500.

[0082] In this embodiment, the optical system condition determination unit 343 selects an irradiator 323 among the plurality of irradiators 323, the distance between the reflection position (monitor position) of the wafer 500 that reflects the light irradiated from the irradiator 323 and the processing position of the wafer 500 being closer than a preset setting distance. The setting distance may be set arbitrarily, but is preferably set to the shortest possible distance.

[0083] The optical system condition determination unit 343 determines the conditions of the optical system 320 by comparing the coordinates of the processing position or the processing target area of ​​the wafer 500 sent from the processing position information acquisition unit 341 with the coordinates of the selectable monitor position in the optical system 320 .

[0084] For example, in Figure 3 312A is the reflected light obtained by reflecting the irradiation light 311A ​​irradiated from the irradiator 323 farthest from the light receiving unit 325 on the wafer 500. In addition, the reflected light 312B is the reflected light obtained by reflecting the irradiation light 311B irradiated from the irradiator 323 closest to the light receiving unit 325 on the wafer 500.

[0085] As can be seen from the figure, by changing the position where light is irradiated in the light irradiation unit 321 , that is, by changing the irradiator 323 used, the reflection position (monitor position) of the reflected light 312 received by the light receiving unit 325 on the wafer 500 changes.

[0086] In addition, Figure 3 In the example shown, twelve irradiators 323 are arranged at intervals of about 10 mm. In this case, by switching the irradiator 323 that irradiates light, the monitor position of the reflected light 312 detected by the light receiving unit 325 can be controlled at intervals of about 5 mm. That is, the optical system condition determination unit 343 can determine a desired irradiator 323 from a plurality of irradiators 323 that have different monitor positions at intervals of about 5 mm.

[0087] In the present embodiment, the optical system condition determination unit 343 determines, for example, a monitor position having coordinates closest to the coordinates of the processing position of the wafer 500 , and determines the irradiator 323 corresponding to the determined monitor position.

[0088] As an example, Figure 4 As shown in FIG. 5 , it is assumed that there are monitor positions P21 to P26 that can be selected in the optical system 320 in the individual pattern 505. In this case, the optical system condition determination unit 343 extracts the combination of the coordinates of the processing positions P11 to P15 as the processing position information and the coordinates of the monitor positions P21 to P25 that are closest in distance. In this example, the combination of the monitor position P21 and the processing position P11 and the combination of the monitor position P24 and the processing position P13 are extracted. Then, the optical system condition determination unit 343 selects one of the monitor position P21 or the monitor position P24, and determines the irradiator 323 corresponding to the selected monitor position.

[0089] In addition, as described above, when information on the coordinates of multiple processing positions P11 to P14 is supplied from the processing position information acquisition unit 341, the optical system condition determination unit 343 can determine the monitor position of the coordinates closest to the coordinates of each processing position P11 to P14, and determine one or more irradiators 323 for performing light irradiation so as to achieve each of the determined monitor positions.

[0090] In addition, when the optical system 320 includes a plurality of light receiving units 325 and the monitor position on the wafer 500 is changed by selecting the light receiving unit 325 , the optical system condition determination unit 343 may select and determine the light receiving unit 325 in coordination with the irradiator 323 described above.

[0091] Furthermore, for example, when the processing position information of the chip 500 is the coordinates for determining the processing object area, the optical system condition determination unit 343 can determine multiple irradiators 323 corresponding to multiple monitor positions included in the processing object area as the irradiators 323 for light irradiation.

[0092] The conditions of the optical system 320 determined by the optical system condition determination unit 343 are supplied to the processing amount calculation unit 345 .

[0093] The processing amount calculation unit 345 calculates the processing amount (etching amount) of the wafer 500 using the specific irradiator 323 based on the information supplied from the optical system condition determination unit 343. The processing amount calculation unit 345 controls the state of the optical system 320, for example, so that the irradiation light 311 is irradiated from the specific irradiator 323 to the wafer 500, and the reflected light 312 is received by the light receiving unit 325. Then, the processing amount calculation unit 345 calculates the processing amount (etching amount) of the wafer 500 based on the detection result introduced from the detection unit 330.

[0094] Figure 5 This is a diagram showing the structure of functional blocks of the processing amount calculation unit according to the first embodiment, particularly, a functional block that calculates the processing amount of a wafer.

[0095] like Figure 5 As shown, the time series data D1 of the light amount of each wavelength introduced into the processing amount calculation unit 345 from the detection unit 330 is first removed / corrected for various noises and fluctuations by the digital signal processing unit 3451 and supplied to the waveform comparator 3452 as the time series data D2.

[0096] For example, a low-pass filter is used to remove noise on the time axis of each wavelength. In addition, for example, in the case of removing the light amount offset of each wavelength and observing the time change of the light amount, a signal processing of calculating the light amount change amount and the differential value during the time period can be used. In the calculation of the differential value, for example, the SG method along the time axis is used. In addition, for example, in the case where there is a change in the light amount of all wavelengths at the same magnification, a signal processing of normalizing the light amount of each wavelength by the average value and the absolute value sum of the light amount of all wavelengths is used.

[0097] The time series data D2 introduced into the waveform comparator 3452 is compared with the previously acquired light quantity data of each wavelength relative to the etching amount, that is, the waveform pattern database 3453. Here, in the waveform comparator 3452, the waveform pattern database (light quantity data) 3453 and the currently obtained time series data D2 are compared to obtain the waveform pattern closest to the current pattern, and the processing amount of the wafer 500 is determined from the closest waveform pattern.

[0098] The determined processing amount D3 is stored in the etching amount storage unit 3454. The light amount data of each wavelength in the waveform pattern database 3453 is data processed by the signal processing implemented by the digital signal processing unit 3451, and it is desired to be processed by the same signal processing as the time series data D2. However, it is not necessary to process by the same signal processing. The etching amount storage unit 3454 sends the time series data D4 of the processing amount to the processing amount correction unit 3455.

[0099] The processing amount correction unit 3455 corrects the processing amount at each time based on the calculated time series transition of the processing amount. As an example, when there is a fluctuation caused by noise or the like in the calculated time series transition of the processing amount, the processing amount correction unit 3455 performs linear approximation on the time transition of the processing amount to correct the processing amount at each time. The processing amount correction unit 3455 outputs the corrected processing amount as processing amount data. For example, the processing amount correction unit 3455 outputs the corrected processing amount as processing amount data to the overall control unit 150.

[0100] In the above example, the waveform comparator 3452 and the waveform pattern database 3453 are used to determine the processing amount (etching amount) D3 using the time series data D2, but machine learning may also be used. In this case, the time series data D2 is input using the information of the waveform pattern database 3453, a learning model or an approximate function with the etching amount D3 as an output is generated, and the etching amount D3 is calculated (estimated) using the generated learning model or approximate function.

[0101] In addition, in the above-mentioned example, the waveform comparator 3452 determines the processing amount D3, but sometimes the error values ​​of more than two waveforms, the intensity values ​​of each waveform, or the frequency value are calculated. For example, in the case of calculating the light quantity data of each wavelength, that is, the error value of the entire spectrum, the waveform comparator 3452 calculates the error of the light quantity of each wavelength or its absolute value, and calculates their sum as the error value. In addition, for example, in the case of calculating the error value of a specific wavelength of the spectrum, the waveform comparator 3452 calculates the error of the light quantity of the specific wavelength or its absolute value, and calculates their sum as the error value. In addition, for example, in the case of calculating the intensity of the spectrum, the waveform comparator 3452 calculates the sum of the intensities of all wavelengths of the spectrum or a specific wavelength as the intensity value. In addition, for example, in the case of calculating the frequency value of the spectrum, the waveform comparator 3452 calculates the vibration frequency of the intensity in the wavelength direction as the frequency value by performing Fourier transform on the spectrum in the wavelength direction.

[0102] Then, the overall control unit 150 performs endpoint determination in the etching process of the wafer 500 based on the throughput data outputted from the throughput calculation unit 345. The method of determining the endpoint in the etching process of the wafer 500 is not particularly limited, and the following method can be cited as an example.

[0103] The overall control unit 150 compares the acquired processing volume data with a predetermined target processing volume to determine whether the current processing volume has reached the target processing volume. If it is determined that the current processing volume has reached the target processing volume, the etching process is terminated.

[0104] According to the plasma processing apparatus 100 according to the first embodiment, it is possible to always measure the reflected light from the processing target area regardless of the pattern layout of the wafer 500. As a result, it is possible to achieve high-precision processing amount measurement (film thickness measurement) and wafer processing end point determination. Furthermore, it is possible to achieve high-precision processing of devices.

[0105] Furthermore, in the plasma processing apparatus 100 according to the first embodiment, the processing amount of the wafer 500 is measured based on the detection result of the reflected light 312 at the monitor position in the processing target area. Therefore, the processing amount can be measured and the end point of wafer processing can be determined with higher accuracy.

[0106] Fig. 6A is a diagram showing the spectrum of reflected light from the electronic circuit portion of the wafer in Embodiment 1, Figure 6B 1 is a diagram showing the spectrum of reflected light from the peripheral portion of the wafer in Embodiment 1. Fig. 6A as well as Figure 6B As known, the spectrum of the reflected light 312 varies depending on the position where the reflected light 312 is obtained. That is, the spectrum of the reflected light 312 in the processing target area, that is, the electronic circuit portion 501 ( Fig. 6A ) and the spectrum of the reflected light 312 outside the processing target area, that is, in the peripheral portion 503 ( Figure 6B Therefore, it is preferable to measure the processing amount of the wafer 500 based on the reflected light at the monitor position in the processing target area, that is, the electronic circuit portion 501.

[0107] In this embodiment, as described above, the reflected light 312 reflected at the monitor position P21 or the monitor position P24 located in the electronic circuit portion 501 is used to measure the processing amount of the wafer 500. Fig. 6A Therefore, it is easy to determine the processing volume of the wafer 500 based on the spectrum of the reflected light 312, and a high-precision endpoint determination can be achieved. In addition, by automatically stopping the etching process based on the endpoint determination, the processing accuracy can be improved. Specifically, the error with the target processing size can be suppressed to less than 1nm, for example.

[0108] In addition, the pattern layout of the wafer 500 described above is an example. In other pattern layouts, the reflected light at the monitor position closest to the processing position can be measured by controlling the reflection position (monitor position) on the wafer 500 of the reflected light 312 to be measured. Furthermore, the reflected light in the processing target area can be measured. That is, even wafers with other pattern layouts can achieve high-precision processing.

[0109] In addition, in this embodiment, as a method for determining the processing amount (etching amount), so-called spectrum matching is used, but the method for determining the processing amount is not particularly limited. For example, the processing amount can be determined using light amount data of a specific wavelength of the spectrum or feature amount data extracted from the spectrum.

[0110] In addition, in this embodiment, the monitor position is set to one, but the monitor position may be multiple. In this case, for example, the average spectrum during processing at multiple monitor positions is measured. Thus, the processing amount measurement, that is, film thickness / depth measurement (estimation) can be performed using information on the average processing state of the processing distribution within the surface of the wafer 500.

[0111] In addition, in the present embodiment, the throughput detection unit 340 provided in the throughput measuring device 300 detects the throughput of the wafer 500 subjected to the etching process, but, for example, the throughput of the wafer 500 may be detected by the overall control unit 150. That is, the plasma processing apparatus 100 includes the throughput detection unit 340 separately from the overall control unit 150, but the overall control unit 150 may also have the function of the throughput detection unit 340.

[0112] (Implementation method 2)

[0113] Figure 7 It is a diagram schematically showing the positional relationship between the light irradiation unit and the light receiving unit according to the second embodiment, and is a diagram of the processing chamber as viewed from above. Figure 8 This is a diagram showing the processing position of the wafer and the monitor position in the second embodiment.

[0114] In the first embodiment, the example in which the irradiators 323 of the light irradiation unit 321 are arranged in a row is described. Figure 7 As shown in the figure, the multiple illuminators 323A constituting the light irradiation unit 321A are arranged in a two-dimensional plane. In other words, the multiple illuminators 323A constituting the light irradiation unit 321A are arranged in multiple rows on the optical system setting surface 600. As for the parts other than this, since they are the same as in Embodiment 1, the description is omitted. In addition, the so-called optical system setting surface 600 refers to the plane on which the optical system 320 is set.

[0115] In this embodiment, the light irradiation unit 321A includes 36 irradiators 323A. These irradiators 323A are arranged in a two-dimensional plane. Specifically, 12 irradiators 323A are arranged in three rows on the optical system installation surface 600.

[0116] By arranging the plurality of irradiators 323A in a two-dimensional plane, it is possible to increase the monitor positions that can be selected by the optical system 320. That is, by arranging the plurality of irradiators 323A in a two-dimensional plane, it is possible to increase the monitor positions that can be irradiated with the irradiation light 311 via the optical system 320.

[0117] In the first embodiment, the monitor positions that can be selected by the optical system 320 are six monitor positions P21 to P26 (see Figure 4 ). In contrast, in implementation mode 2, as Figure 8 As shown, the monitor positions that can be selected by the optical system 320 are 12 monitor positions P21 to P32. Therefore, the optical system condition determination unit 343 can determine more appropriate monitor positions and corresponding irradiators 323A for the processing positions P11 to P18 of the wafer 500.

[0118] In addition, the optical system condition determination unit 343 compares the coordinates of the processing positions P11 to P18 of the wafer 500 with the coordinates of the monitor positions P21 to 32, and extracts the combination with the closest distance between the coordinates, as in the first embodiment. Figure 8 In the example of , the combinations with the closest distances between coordinates are the combination of the processing position P15 and the monitor position P27, and the combination of the processing position P17 and the monitor position P30.

[0119] Then, the processing amount calculation unit 345 controls the light irradiation unit 321 and the like of the optical system 320 so that the reflection position of the reflected light 312 becomes the monitor position P27 or the monitor position P30. That is, the processing amount calculation unit 345 performs film thickness / depth estimation (estimation of etching amount) in the etching process and endpoint determination of the etching process based on the detection result of the reflected light 312 reflected at the monitor position P27 or the monitor position P30.

[0120] Thus, similarly to the first embodiment, it is possible to achieve high-precision measurement of the etching processing amount and endpoint determination, and thus, high-precision processing of the device can be achieved.

[0121] In addition, Figure 8 In the example shown, it is considered that the monitor positions P21, P24, P27, and P30 are within the processing target area, that is, the electronic circuit portion 501. Therefore, by irradiating light from a plurality of irradiators 323A so that the spectra of the reflected light 312 from the monitor positions P21, P24, P27, and P30 are detected at the light receiving portion 325 at the same time, a more appropriate end point determination can be achieved based on the average processing conditions of the plurality of electronic circuit portions 501.

[0122] (Implementation method 3)

[0123] Fig. 9 It is a diagram schematically showing the positional relationship between the light irradiation unit and the light receiving unit according to the third embodiment, and is a diagram of the processing chamber as viewed from above. Fig.10 This is a diagram showing an example of a wafer processing position and a monitor position in the third embodiment.

[0124] The plasma processing apparatus 100 according to the third embodiment includes a plurality of irradiators 323B formed of lens-integrated LEDs as light irradiation units 321B constituting the optical system 320. The other configurations are the same as those of the second embodiment, and thus description thereof is omitted.

[0125] like Fig. 9 As shown, the light irradiation unit 321B is composed of 48 lens-integrated LEDs, which are arranged on the optical system installation surface 600. That is, in the third embodiment, the plurality of irradiators 323B are also arranged in a two-dimensional plane.

[0126] In this embodiment, as the information of the processing target area, the processing position information acquisition unit 341 is as follows: Fig.10 As shown, information on the coordinates of the four corners P51a to P51d of the substantially rectangular electronic circuit portion 501 is acquired as information on the processing position and supplied to the optical system condition determination portion 343.

[0127] The optical system condition determination unit 343 selects a monitor position, among the plurality of monitor positions, whose distance to the electronic circuit unit 501 specified by the coordinates of the positions P51a to P51d is closer than a preset set distance, and more preferably selects a monitor position whose distance to the electronic circuit unit 501 is closest. More preferably, the optical system condition determination unit 343 selects a monitor position located inside the electronic circuit unit 501.

[0128] exist Fig.10 In the example shown, the electronic circuit portion 501, which is the processing target area of ​​the wafer 500, is defined as a range defined by positions P51a to P51d. Fig.10 In the illustrated example, monitor positions selectable by the optical system 320 near the electronic circuit portion 501 are monitor positions P31 to P42.

[0129] The optical system condition determination unit 343 compares the range of processing positions defined by the positions P51a to P51d with the monitor positions P31 to P42 to determine the monitor positions included in the processing target area, that is, the electronic circuit unit 501. Fig.10 In the example shown, three monitor positions P34 , P35 , and P36 are determined as monitor positions included in the electronic circuit portion 501 .

[0130] By measuring the etching processing amount (measuring the film thickness during etching) and determining the end point of the processing based on the detection results of the reflected light 312 reflected at the monitor positions P34, P35, and P36 determined in this way, it is possible to achieve high accuracy in measuring the processing amount and determining the end point of the processing, as in the above-mentioned embodiment. Furthermore, high-precision processing of the device can be achieved.

[0131] (Implementation method 4)

[0132] Embodiment 4 is an example in which the coordinates of the measurement position of the inspection device as an external device are used as the processing position information of the wafer 500 in the structure of Embodiment 1. The rest is the same as that of Embodiment 1, and therefore the description thereof is omitted.

[0133] The wafer 500 to be processed by the plasma processing apparatus 100 is subjected to etching processing by the wafer processor 200 and then the processed shape is measured by an electron microscope.

[0134] Although not shown in the figure, the plasma processing apparatus 100 is communicatively connected to the electron microscope via a cable etc. The processing position information acquisition unit 341 acquires the measurement position of the processed shape by the electron microscope and supplies the acquired measurement position to the optical system condition determination unit 343 as processing position information.

[0135] For example, in Figure 4 In the example shown, when the position where the processed shape is measured by the electron microscope corresponds to the processing position P13 on the wafer 500 , the processing position information acquisition unit 341 acquires the coordinates of the processing position P13 as the processing position information and supplies the acquired processing position information to the optical system condition determination unit 343 .

[0136] Even the plasma processing apparatus according to the fourth embodiment can achieve high accuracy in processing amount measurement and processing end point determination, similarly to the above-mentioned embodiments, and can achieve high-precision processing of devices.

[0137] (Implementation method 5)

[0138] Embodiment 5 is an example in which the optical system condition determination unit 343 determines the irradiator 323 for light irradiation based on the result of the trial irradiation by the light irradiation unit 321. Other aspects are the same as those of Embodiment 1, and therefore, the description here is omitted.

[0139] More specifically, in the plasma processing apparatus 100 according to the fifth embodiment, before the etching process of the wafer 500, the wafer 500 is subjected to trial irradiation by each irradiator 323 of the light irradiation unit 321. Then, the optical system condition determination unit 343 determines the irradiator 323 used for the processing amount measurement based on the spectrum of the reflected light 312 obtained by the trial irradiation. Therefore, in the present embodiment, the processing position information acquisition unit 341 does not supply the processing position information to the optical system condition determination unit 343.

[0140] For example, in Figure 4 In the example shown, test irradiation is performed on monitor positions P21 to P26 in the individual pattern 505 of the wafer 500, and the spectrum of the reflected light 312 reflected at these monitor positions P21 to P26 is obtained. Fig.11 Shown.

[0141] like Fig.11As shown in FIG. 1 , the shape of the spectrum of the reflected light 312 is different at each monitor position P21 to P26. In Embodiment 5, the optical system condition determination unit 343 compares the spectrum of the reflected light 312 at each monitor position P21 to P26 with a preset reference spectrum, and determines the monitor position that can obtain a spectrum closest to the reference spectrum. In this embodiment, the reference spectrum is the spectrum of the reflected light at the processing position. Therefore, the monitor position in this embodiment determined in this way can also be said to be the monitor position closest to the processing position or processing nickname area of ​​the wafer 500.

[0142] According to the plasma processing apparatus according to the fifth embodiment, as in the above-mentioned embodiments, it is possible to achieve high accuracy in measuring the amount of processing and determining the end point of processing, and thus to achieve high-precision processing of devices.

[0143] In addition, in this embodiment, an example of setting the spectrum of reflected light at the processing position as the reference spectrum is described. However, the reference spectrum does not necessarily have to be the spectrum of reflected light at the processing position, and can be set to the spectrum of reflected light at any position of the wafer 500.

[0144] As described above, in this embodiment, an example is described in which the processing amount detection unit 343 selects the irradiator 323 of the plurality of irradiators 323 , the distance between the reflection position of the wafer 500 reflecting the light irradiated from the irradiator 323 and the processing position of the wafer 500 being closest.

[0145] However, the throughput detection unit 343 does not necessarily have to select the irradiator 323 whose reflection position of the wafer 500 is closest to the processing position of the wafer 500. The throughput detection unit 343 may determine the irradiator 323 to irradiate light from among the plurality of irradiators 323 based on the difference between the information of each reflection position of the wafer 500 that reflects the light irradiated from the plurality of irradiators 323 and the information of the processing position of the wafer 500.

[0146] (Implementation method 6)

[0147] Embodiment 6 is an example in which the monitor position is determined according to the signal strength based on the result of the test irradiation in Embodiment 5. Other aspects are the same as those of Embodiment 5, and thus description thereof will be omitted.

[0148] More specifically, in this embodiment, the optical system condition determination unit 343 calculates the error value between the spectrum of the reflected light 312 at each monitor position obtained by the test irradiation and the reference spectrum, and determines the monitor position based on the error value. The error value is calculated as the sum of the absolute values ​​of the errors at each wavelength of the spectrum.

[0149] Fig.12FIG. 1 is a diagram showing an example of calculation results of error values ​​between the spectrum of reflected light at each monitor position and the reference spectrum in Embodiment 6. Fig.12 In the graph, the horizontal axis is the coordinate of the monitor position and the vertical axis is the error value.

[0150] The spectrum of the reflected light 312 can be defined as follows: the smaller the error value, the closer it is to the reference spectrum, and the higher the signal strength (the smaller the noise). Fig.12 In the example shown, the reflected light at the monitor position P21 with the lowest error value is determined to have the highest signal intensity, and the monitor position P21 is determined as the monitor position used for film thickness / depth estimation and endpoint determination.

[0151] According to the plasma processing apparatus according to the sixth embodiment, as in the above-mentioned embodiments, it is possible to achieve high accuracy in measuring the amount of processing and determining the end point of processing, and thus to achieve high-precision processing of devices.

[0152] In addition, in this embodiment, the signal intensity is calculated based on the error value with the reference spectrum, but the calculation method of the signal intensity is not limited to this. For example, during the test irradiation, when the reflectivity of the processing position of the wafer 500 is high and the reflectivity of the other parts is low, the intensity value of the spectrum of the reflected light obtained by the test irradiation, which is the sum of the intensities of each wavelength, can be set as the signal intensity.

[0153] In addition, for example, when the spectrum of reflected light reflected at the processing position of the chip 500 contains vibrations in the light intensity in the wavelength direction caused by a thick transparent film, and there is no vibration in the light intensity in the wavelength direction in parts other than this, the signal intensity can be calculated using the frequency value of the frequency of the vibration of the light intensity in the wavelength direction of the spectrum obtained by test irradiation.

[0154] In this case, the signal strength can be defined as the error amount of the frequency value from the target. Specifically, the monitor position with the smallest error amount is determined as the monitor position with the highest signal strength.

[0155] The above-mentioned technology of the present disclosure is specifically described based on the embodiments, but the technology of the present disclosure is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the gist thereof, which is self-evident. In addition, for example, the above-mentioned embodiments are described in detail in order to easily explain the technology of the present disclosure, but are not necessarily limited to all the structures described. In addition, other structures can be added, deleted, or replaced with a part of the structure of the above-mentioned embodiments.

[0156] Description of Reference Numerals

[0157] 100: Plasma treatment device

[0158] 150: Overall Control Department

[0159] 200: Chip processor

[0160] 201: Plasma

[0161] 203: Processing Room

[0162] 205: Vacuum container

[0163] 207: Sample stage

[0164] 209: Window components

[0165] 211: Shower Board

[0166] 211a: Gas inlet hole

[0167] 213: Exhaust port

[0168] 215: Vacuum pump

[0169] 217: Exhaust volume regulating valve

[0170] 219: Electric field / magnetic field formation unit

[0171] 221: Waveguide

[0172] 223: Power supply for electric field generation

[0173] 225: Magnetic field generating coil

[0174] 227: Hollow

[0175] 300: Processing capacity measuring device

[0176] 310: Light source

[0177] 311: Illuminating light

[0178] 312: Reflected Light

[0179] 320: Optical system

[0180] 321: Light irradiation unit (multi-point irradiation port)

[0181] 323: Illuminator (Illuminating optical port)

[0182] 325: Light receiving part (light receiving port)

[0183] 330: Inspection Department

[0184] 340: Processing volume detection unit

[0185] 341: Processing position information acquisition unit

[0186] 343: Optical system condition determination department

[0187] 345: Processing volume calculation unit

[0188] 3451: Digital Signal Processing Department

[0189] 3452: Waveform Comparator

[0190] 3453: Waveform Pattern Database

[0191] 3454: Etching amount storage unit

[0192] 3455: Processing volume correction unit

[0193] 500: Chip (semiconductor chip)

[0194] 501: Electronic Circuit Department

[0195] 503: Peripheral Department

[0196] 505: Single pattern

[0197] 600: Optical system setting surface.

Claims

1. A plasma processing device, comprising: a processing chamber inside a vacuum vessel; The sample stage is arranged in the processing chamber and has a wafer as a processing target placed on its upper surface. The plasma processing device is characterized in that it has: a light irradiation unit having a plurality of irradiators for irradiating light to respectively different positions on the surface of the wafer placed on the sample stage; a light receiving unit that receives reflected light obtained by the light irradiated from the plurality of irradiators being reflected by the wafer; and a processing amount detection unit for detecting the processing amount of the wafer based on information obtained from the reflected light received by the light receiving unit during processing of the wafer, The processing volume detection unit determines an irradiator for light irradiation from among the multiple irradiators based on the difference between information on each reflection position of the chip that reflects light irradiated from the multiple irradiators and information on the processing position of the chip, and uses the determined irradiator to detect the processing volume of the chip.

2. The plasma processing device according to claim 1, wherein: The processing amount detection unit selects an irradiator among the multiple irradiators, the distance between the reflection position of the wafer reflecting the light irradiated from the irradiator and the processing position of the wafer being closer than a preset set distance, and uses the selected irradiator to detect the processing amount of the wafer.

3. The plasma processing device according to claim 2, wherein: The throughput detection unit selects an irradiator from among the plurality of irradiators, the distance between a reflection position of the wafer reflecting irradiation light emitted from the irradiator and a processing position of the wafer being closest, and detects the throughput of the wafer using the selected irradiator.

4. The plasma processing device according to claim 2, wherein: The processing amount detection unit calculates a distance between the reflection position and the processing position on the wafer based on the coordinates of the processing position and the coordinates of the reflection position on the surface of the wafer.

5. The plasma processing apparatus according to claim 1, wherein: The throughput detection unit selects the irradiator used for detecting the throughput of the wafer based on a result of comparing the spectrum of the reflected light received by the light receiving unit with a preset reference spectrum.

6. The plasma processing apparatus according to claim 1, wherein: The irradiators are respectively composed of a lens and an optical fiber.

7. The plasma processing apparatus according to claim 1, wherein: The illuminators each have an LED light source.

8. A plasma processing method, which is a plasma processing method using a plasma processing device, The plasma processing device comprises: a processing chamber inside a vacuum vessel; A sample stage, which is arranged in the processing chamber and has a wafer as a processing target placed on its upper surface; a light irradiation unit including a plurality of irradiators for irradiating light to respectively different positions on the surface of the wafer placed on the sample stage; and a light receiving unit that receives reflected light obtained by the light irradiated from the plurality of irradiators being reflected by the wafer, The plasma treatment method is characterized in that: An irradiator for light irradiation is determined from among the multiple irradiators based on a difference between information about each reflection position of the chip that reflects light irradiated from the multiple irradiators and information about a processing position of the chip, the determined irradiator is used to detect a processing amount of the chip, and processing of the chip is controlled based on the detected processing amount.

9. The plasma processing method according to claim 8, wherein: An irradiator is selected from among the plurality of irradiators, the distance between a reflection position of the wafer reflecting light irradiated from the irradiator and a processing position of the wafer being closer than a preset distance, and the processing amount of the wafer is detected using the selected irradiator.

Images