End point detection device, etching control system, end point detection method, and recording medium

Abstract

The present invention provides an end point detection device, an etching control system, an end point detection method, and a recording medium, the end point detection device detects an end point of a multilayer film in an etching process, and comprises: a measurement unit that measures a physical quantity that varies in accordance with the etching process; an end point detection unit that detects, on the basis of the measurement value obtained by the measurement unit, the end point of the film to be detected by a predetermined detection algorithm; and an algorithm changing unit that changes the detection algorithm for the film being etched on the basis of a measured value obtained by the measuring unit when etching another film of the same type as the target film among the multiple layers of films that are the same as the target film being etched previously.

Description

Technical Field

[0001] The present invention relates to an endpoint detection device, an etching control system, an endpoint detection method, and a recording medium. Background Art

[0002] In the case of performing an etching process on a semiconductor wafer in a semiconductor manufacturing process, a technique for stopping the etching process at a desired depth has become more important. This is because the surface roughness of the film after the etching process has a great influence on the characteristics of semiconductor devices. In addition, a technique for detecting the endpoint in the etching process in real time is required to improve the yield.

[0003] Especially in a wafer having a multilayer film (hereinafter referred to as a multilayer film wafer), when deep etching is performed on the same wafer, the greater the depth and the smaller the aperture ratio, the more difficult it is to detect the endpoint.

[0004] Here, as in Patent Document 1, a method of determining the endpoint of the etching process by measuring the temporal change in the plasma emission intensity from the etching chamber using emission spectroscopy is considered.

[0005] However, there are cases where the endpoint cannot be accurately obtained by emission spectroscopy due to a decrease in emission intensity caused by a non-plasma process that cannot be measured by emission spectroscopy, a decrease in the aperture ratio, or a decrease in the etching rate accompanying an increase in the etching depth.

[0006] Prior Art Documents Patent Documents Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-7084 Summary of the Invention

[0007] Technical Problem Therefore, the present invention has been made to solve the above problems, and an object thereof is to perform an etching process of a multilayer film with high precision by accurately obtaining the endpoint.

[0008] Technical Solution That is, the endpoint detection device of the present invention is characterized in that it detects the endpoint of a multilayer film in an etching process, and the endpoint detection device includes: a measurement unit that measures a physical quantity that changes with the etching process; an endpoint detection unit that detects the endpoint of a film to be detected for the endpoint by a predetermined detection algorithm based on the measurement value obtained by the measurement unit; and an algorithm change unit that changes the detection algorithm of the film in the etching process based on the measurement value obtained by the measurement unit when etching another film of the same type as the film to be detected in a multilayer film that is the same as the film to be detected in the etching process.

[0009] If it is such an endpoint detection device, since the detection algorithm for the endpoint of the film being etched in the multilayer film is changed based on the measurement values obtained by the measurement unit when etching other films of the same type as the film being etched in the same multilayer film as before, the endpoint of the film being etched can be accurately obtained. As a result, the etching process of the multilayer film can be performed with high precision.

[0010] As a specific implementation manner of the algorithm change unit, it is desirable that the algorithm change unit changes the detection algorithm for the endpoint of the film being etched based on more than two past measurement values obtained by the measurement unit when etching other films of the same type as the film being etched in the same multilayer film as before.

[0011] If it is this configuration, by using more than two past measurement values, the detection algorithm for the endpoint of the film being etched can be changed to the optimal algorithm.

[0012] As a specific implementation manner of the algorithm change unit, it is desirable that the algorithm change unit changes the detection threshold for the endpoint of the film being etched.

[0013] As a specific implementation manner of the endpoint detection unit, it is desirable that the endpoint detection unit calculates the transfer time between the transfer start point and the transfer end point when the film being etched transfers from the film being etched to the next film.

[0014] It is desirable that the endpoint detection device of the present invention further includes a data storage unit that stores relationship data representing the relationship between the transfer time between the transfer start point and the transfer end point among the measurement values obtained by the measurement unit when etching other films of the same type as the film being etched in the same multilayer film as before, and the slope of the measurement values during this period. The endpoint detection unit calculates the transfer time from the film being etched to the next film based on the relationship data and the slope of the film being etched after the transfer start point.

[0015] If it is this configuration, even when the film thickness of the film being etched is different from that of the same type of film etched before, the transfer time from the film being etched to the next film can be accurately obtained.

[0016] It is desirable that the endpoint detection device of the present invention further includes a display control unit that displays the time-series change of the measurement values obtained by the measurement unit on a display.

[0017] If it is this configuration, by displaying the time-series change of the measured value on the display, it can be a reference for the user to change the etching process.

[0018] As a specific embodiment of the measurement unit, it is desirable that the measurement unit performs absorbance measurement on the reaction product generated by the etching process. For example, since the reaction product generated by the etching process is measured by absorbance spectroscopy, even a non-plasma process that could not be measured by emission spectroscopy in the past can detect the end point.

[0019] In addition, it is desirable that the etching control system of the present invention includes: an etching control device that controls an etching processing device for etching a multilayer film; and the above-described end point detection device. If the end point detection device detects a transfer start point indicating the start of transfer from the film being etched in the etching process to the next film, the etching control device changes the etching process of the film being etched in the multilayer film.

[0020] If it is this etching control system, since the etching process of the film being etched is changed after detecting the transfer start point indicating the start of transfer from the film being etched in the etching process to the next film, the best process can be set, and thus the etching process can be performed with high precision.

[0021] It is desirable that the etching control device changes the etching rate of the film being etched in the multilayer film. Here, changing the etching rate includes, for example, adjusting the flow rate of the reactive gas introduced into the process chamber for etching, changing the plasma power generated in the process chamber, or changing the temperature (reaction temperature) of the object to be etched (e.g., a wafer).

[0022] Furthermore, it is desirable that the end point detection method of the present invention is an end point detection method for detecting the end point of a multilayer film in an etching process. A physical quantity that changes with the etching process is measured by a measurement unit, and the end point of the film as the object to be detected for the end point by a predetermined detection algorithm is detected based on the measured value obtained by the measurement unit. The detection algorithm of the film being etched is changed based on the measured value obtained by the measurement unit when etching other films of the same type as the film being etched in the same multilayer film as the film being etched in the past.

[0023] On this basis, the recording medium of the present invention is characterized in that it records an endpoint detection program used by an endpoint detection device for detecting the endpoint in the etching process of a multilayer film. The endpoint detection program enables a computer to have: as a function of a reception unit, receive measurement value data from a measurement unit that changes with the etching process; as a function of an endpoint detection unit, detect the endpoint of a film to be detected for the endpoint by a predetermined detection algorithm based on the measurement values obtained by the measurement unit; and as a function of an algorithm change unit, change the detection algorithm of the film in the etching process based on the measurement values obtained by the measurement unit when etching other films having the same composition as the film to be detected in the same multilayer film during the etching process.

[0024] It should be noted that the endpoint detection program can be a program distributed electronically or a program recorded on a program recording medium such as a CD, DVD, or flash memory. In addition, the endpoint detection program can also be assembled on the mother board of the device main body.

[0025] Technical effects Thus, according to the present invention, by accurately obtaining the endpoint, the etching process of the multilayer film can be performed with high precision. Brief description of the drawings

[0026] Figure 1 FIG. schematically shows the configuration of an etching control system according to an embodiment of the present invention.

[0027] Figure 2 FIG. schematically shows a cross-sectional view of a substrate having the multilayer film structure of this embodiment.

[0028] Figure 3 FIG. shows a chart of the time-series change of the measurement values of the measurement unit of this embodiment.

[0029] Figure 4 FIG. shows the measurement values of the first-layer SiO film, the third-layer SiO film, and the fifth-layer SiO film (and the values of the first-order derivative) for representing the calculation method of the transfer time of this embodiment.

[0030] Symbol description 100... Etching control system 2... Etching control device 3... Endpoint detection device 31... Measurement unit 32... Endpoint detection unit 33... Algorithm change unit 34... Display control unit D1... Data storage unit 4... Display Detailed implementation mode

[0031] <One embodiment of the present invention> Hereinafter, an embodiment of an etching control system incorporating the end point detection device of the present invention will be described with reference to the drawings. It should be noted that for any of the figures shown below, for the sake of easy understanding, appropriate omissions or exaggerations are made and schematically described. The same reference numerals are assigned to the same components and the description is appropriately omitted.

[0032] <Device configuration> As Figure 1 shown, the etching control system 100 of the present embodiment controls an etching processing apparatus 200 for performing etching processing such as plasma etching. As Figure 2 shown, the object W of the etching processing here has, for example, a multilayer film structure formed on the main surface of a silicon substrate. As the multilayer film structure, a structure in which two types of films (here, SiO film and SiN film) are alternately formed is considered. It should be noted that the multilayer film structure may also be a structure in which three or more types of films are periodically formed.

[0033] In addition, the etching processing apparatus 200 includes a process chamber 201 for performing etching processing, a plasma generation mechanism (not shown) for generating plasma P in the process chamber 201, and a gas introduction mechanism 202 for introducing a reactive gas into the process chamber 201. The gas introduction mechanism 202 is provided with a flow rate adjustment mechanism 202a (for example, a mass flow controller) for adjusting the flow rate of the reactive gas introduced into the process chamber 201.

[0034] Specifically, as Figure 1 shown, the etching control system 100 includes: an etching control device 2 that controls the etching processing apparatus 200 for etching a multilayer film; and an end point detection device 3 that detects the end point of the multilayer film during the etching processing.

[0035] <Etching control device 2> The etching control device 2 etches the multilayer film by controlling the etching processing apparatus 200.

[0036] Specifically, the etching control device 2 is a device that controls the etching processing apparatus 200 based on a procedure preset for each film in the multilayer film, and controls the etching processing of the multilayer film by controlling the evacuation of the process chamber 201, the generation of plasma by the plasma generation mechanism, and the introduction of the reactive gas by the gas introduction mechanism 202, etc. The etching control device 2 can control the etching rate by controlling the flow rate adjustment mechanism 202a of the gas introduction mechanism 202, etc.

[0037] <End point detection device 3> The endpoint detection device 3 detects the endpoint of the multilayer film during the etching process, and also detects the transfer of the film being currently etched in the multilayer film to the next film.

[0038] It should be noted that in the following embodiments, the endpoint refers to the termination point of the transfer time from the film being currently etched to the next film. It should be noted that the endpoint can be artificially determined by comparing the signal obtained by the measurement unit 31 described later and the etching process result. For example, the starting point of the transfer period can also be used as the endpoint, and the midpoint of the transfer period can also be used as the endpoint.

[0039] Specifically, the endpoint detection device 3 includes a measurement unit 31 and an endpoint detection unit 32. The measurement unit 31 measures a physical quantity that changes with the etching process, and the endpoint detection unit 32 changes the detection algorithm of the endpoint of the film being currently etched in the multilayer film based on the measurement value obtained by the measurement unit 31 to detect the endpoint.

[0040] The measurement unit 31 of the present embodiment measures the reaction product (by-product) generated by the etching process by absorption spectroscopy. Specifically, the measurement unit 31 uses infrared laser absorption spectroscopy and has: a laser light source 31a that irradiates infrared laser into the process chamber 201 or the exhaust pipe 203 connected to the process chamber 201; a light detector 31b that detects the infrared laser passing through the process chamber 201 or the exhaust pipe 203 connected to the process chamber 201; and an arithmetic unit 31c that uses the light intensity signal of the light detector 31b to calculate the concentration or partial pressure of the component to be measured. It should be noted that the measurement unit 31 of the present embodiment uses the infrared laser absorption modulation method (Japanese Patent No. 6886507), but other absorption spectroscopy methods can also be used.

[0041] Here, the laser light source 31a is a semiconductor laser. Specifically, the laser light source is a quantum cascade laser (QCL: Quantum Cascade Laser), which is a type of semiconductor laser, and oscillates mid-infrared (2.5 to 25 μm) laser. The laser light source 31a can modulate (change) the oscillation wavelength according to the applied current (or voltage). It should be noted that other types of lasers can also be used as long as the oscillation wavelength is variable, and the temperature can also be changed to change the oscillation wavelength.

[0042] In addition, the light detector 31b can be, for example, a thermal type light detector such as a thermopile, or a light detector using quantum type photoelectric elements such as HgCdTe, InGaAs, InAsSb, or PbSe.

[0043] The operation unit 31c calculates the absorption signal (absorbance signal) of the gas by calculating based on the optical intensity signal output from the optical detector 31b, extracts the characteristic quantity from the absorption signal, and thus calculates the concentration or partial pressure of the component to be measured. The concentration or partial pressure of the component to be measured calculated by the operation unit 31c is output as a measurement value to the end point detection unit 32 and the algorithm change unit 33. It should be noted that the operation unit 31c includes an analog circuit composed of a buffer, an amplifier, etc., a digital circuit composed of a CPU, a memory, etc., and an AD converter, a DA converter, etc. that establish a relationship between these analog / digital circuits.

[0044] Based on the measurement value obtained by the measurement unit 31, the end point detection unit 32 detects the end point of the film as the object that detects the end point by a predetermined detection algorithm, and also detects the case of transferring from the film being etched currently in the multilayer film to the next film. Here, the end point detection unit 32 can detect the end point of the multilayer film during the etching process based on the measurement value itself obtained by the measurement unit 31 or other parameters obtained based on the measurement value.

[0045] In addition, the algorithm change unit 33 changes the detection algorithm of the film being etched currently based on the measurement value obtained by the measurement unit 31 when etching other films having the same composition as the film being etched currently in the same multilayer film previously. Here, the algorithm change unit 33 can change the detection algorithm based on the measurement value itself obtained by the measurement unit 31 or parameters related to the end point obtained based on the measurement value (for example, transfer time, slope of the measurement value, value obtained by differentiating the measurement value once, value obtained by differentiating the measurement value twice, etc.). It should be noted that the same type of film refers to a film having the same constituent components, crystal structure, etc.

[0046] Here, the "measurement value obtained by the measurement unit 31 when etching previously" refers to the measurement value obtained by the measurement unit 31 when etching other films of the same type as the film being etched currently in the multilayer film being etched currently previously. For example, when the film being etched currently in the multilayer film is, for example, the 5th layer SiO film, it is the measurement value obtained by the measurement unit 31 when etching the SiO film of the 1st layer or the 3rd layer, which is a layer above the 5th layer in the multilayer film, previously.

[0047] In addition, as Figure 3 shown, the detection method of the end point detection unit 32 in this embodiment is performed by detecting the transfer start point (first change point X1) and the transfer end point (second change point X2) of the transfer from the film being etched currently to the next film in the time series chart of the measurement value.

[0048] Specifically, asFigure 3 As shown, the end point detection unit 32 uses two regression lines L1 and L2 to detect the transfer start point (the first change point X1). Additionally, two regression lines L3 and L4 are used to detect the transfer end point (the second change point X2). Here, by detecting the transfer end point (the second change point X2) by the end point detection unit 32, it can be determined that the etching process of the film currently undergoing the etching process is completed.

[0049] Moreover, the algorithm change unit 33 changing the detection algorithm of the end point detection unit 32 includes changing the parameters used in the above detection method, including changing the period during which regression analysis is not performed on the end point, the period during which regression analysis is performed on the end point, the confidence interval of the regression line, the period during which end point determination is not performed, the threshold value of the measured value, the detection threshold value of the end point, or the filter frequency, etc.

[0050] <Calculation Method 1 of Transfer Time> The end point detection unit 32 calculates the transfer time from the film currently undergoing the etching process to the next film based on two or more past measured values obtained by the measurement unit 31 when etching other films of the same type as the film currently undergoing the etching process. It should be noted that in the following, the film undergoing the etching process is a SiO film, but the same applies even if the film undergoing the etching process is a SiN film.

[0051] For example, as Figure 4 shown, in a multilayer film, when the film currently undergoing the etching process is the 5th layer SiO film, based on the measured values obtained by the measurement unit 31 when etching the 1st layer SiO film and the measured values obtained by the measurement unit 31 when etching the 3rd layer SiO film, the transfer time of the 5th layer SiO film, which is the film currently being etched, is calculated. It should be noted that the transfer time refers to the elapsed time from the transfer start point (here, the transfer start point from the 5th layer to the 6th layer) to the transfer end point (here, the transfer end point from the 5th layer to the 6th layer).

[0052] Specifically, by obtaining the ratio of the transfer time of the 1st layer SiO film and the transfer time of the 3rd layer SiO film, the transfer time of the 5th layer SiO film can be calculated. It should be noted that in addition to using the measured values themselves obtained by the measurement unit 31, the values obtained by differentiating the measured values once or twice can also be used.

[0053] For example, when the transfer time of the 1st layer SiO is T1 and the transfer time of the 3rd layer SiO is T3 (= T1 × k (coefficient)), the transfer time T5 of the 5th layer SiO can be set as T5 = T3 × k = T1 × k 2Thus, the transfer time T5 of the fifth-layer SiO can be calculated, and the time to reach the end point can be predicted.

[0054] <Calculation Method 2 of Transfer Time> In addition, the end point detection unit 32 calculates the transfer time from the film being currently etched to the next film based on the relationship between the transfer time and the slope of the measured values during this period in the measured values obtained by the measurement unit 31 when etching a film of the same type as the film being currently etched, and the slope of the measured values after the transfer start point of the film being currently etched.

[0055] Here, the relationship data representing the relationship between the transfer time between the transfer start point and the transfer end point in the measured values obtained by the measurement unit when etching a film of the same type as the film being currently etched and the slope of the measured values during this period is stored in the data storage unit D1 (refer to Figure 1 ). In this embodiment, the relationship between the transfer time and the slope of the measured value is the ratio (α / T) between the slope (α) of the measured value within the transfer time (T) and the transfer time (T). In addition, this relationship data can also be data calculated by the end point detection unit 32, or data calculated by an external arithmetic device.

[0056] For example, as Figure 4 shown, if the end point detection unit 32 uses the ratio (α1 / T1) of the slope (α1) of the measured value within the transfer time T1 of the first-layer SiO film to detect the slope (α3) of the third-layer SiO film after the transfer start point, then the transfer time T3 of the third-layer SiO film can be obtained as T3 = (α3 / α1) × T1 based on the slope (α3) of the measured value within the transfer time T3 of the third-layer SiO film detected and the ratio (α1 / T1) of the first-layer SiO. In addition, if the end point detection unit 32 uses the ratio (α3 / T3) of the slope (α3) of the measured value within the transfer time T3 of the third-layer SiO film to detect the slope (α5) of the fifth-layer SiO film after the transfer start point, then the transfer time T5 of the fifth-layer SiO film can be obtained as T5 = (α5 / α3) × T3 based on the slope (α5) of the measured value within the transfer time T5 of the fifth-layer SiO film detected and the ratio (α3 / T3) of the third-layer SiO.

[0057] In addition, the endpoint detection device 3 may include a data storage unit D1 that stores the time-series data of the measurement values of each layer obtained by the measurement unit 31, and a display control unit 34 that displays the time-series data of the measurement values of each layer on the display 4. The display control unit 34 can not only display the time-series data of the measurement values of each layer, but also display the data of its first derivative or second derivative, and can also display the transfer time calculated by the endpoint detection unit 32, etc.

[0058] It should be noted that the above-mentioned endpoint detection unit 32, algorithm change unit 33, display control unit 34, and data storage unit D1 are constituted by a so-called computer having a CPU, a memory, an A / D converter, a D / A converter, and input / output means, and various devices cooperate by executing the endpoint detection program stored in the memory, thereby functioning as the endpoint detection unit 32, algorithm change unit 33, display control unit 34, data storage unit D1, etc.

[0059] Moreover, if the endpoint detection device 3 detects a transfer start point indicating the start of the transfer from the film being currently etched to the next film, the etching control device 2 can change the etching recipe of the film being currently etched.

[0060] Specifically, consider that the etching control device 2 changes the etching rate of the film being currently etched. At this time, the etching control device 2 controls the etching rate by controlling the flow rate adjustment mechanism 202a of the gas introduction mechanism 202, etc. For example, consider that the etching control device 2 reduces the flow rate of the reactive gas by controlling the flow rate adjustment mechanism 202a, thereby reducing the etching rate. In addition to this, consider reducing the etching rate by changing the plasma power generated in the process chamber. In addition, consider reducing the etching rate by changing the temperature (reaction temperature) of the object to be etched (e.g., wafer). In addition, the flow rate of the reactive gas, etc. can be continuously or stepwise changed as the transfer time elapses. And if the transfer time of the film being currently processed has elapsed, the etching control device 2 can stop the etching process or change to a recipe corresponding to the next film.

[0061] <Effect of this Embodiment> Thus, according to the etching control system 100 in the present embodiment, since the detection algorithm for the endpoint of the film being currently etched in the multilayer film is changed based on the measured values obtained by the measurement unit 31 when etching other films of the same type as the film being currently etched, the endpoint of the film being currently etched can be accurately obtained. As a result, the etching process of the multilayer film can be performed with high precision. In addition, since the reaction products generated by the etching process are measured by absorption spectroscopy, even in a process where reaction products that cannot be measured by emission spectroscopy are generated as in the past, the endpoint can be detected.

[0062] <Other Embodiments> For example, in the above embodiment, the endpoint detection device is assembled into the etching control system, but it is also possible not to assemble the endpoint detection device into the etching control system. In this case, it can also be configured such that the user feeds back data such as the transfer time obtained by the endpoint detection device to the etching control device.

[0063] In addition, when the thicknesses of multiple films of the same type in the multilayer film are different, as long as the relationship between these film thicknesses and the etching rate is known in advance, it is also possible to correct the transfer time and the like measured by the endpoint detection unit 32 based on these.

[0064] In addition, in the above embodiment, the endpoint of the etching process is detected, but it can also be applied to detect the endpoint of chamber conditioning such as cleaning of the process chamber 201.

[0065] The measurement unit 31 in the above embodiment uses absorption spectroscopy such as infrared laser absorption spectroscopy, but optical measurement methods such as emission spectroscopy or ICP emission spectroscopy can also be used. In addition, the measurement unit 31 can also use mass spectrometry such as quadrupole mass spectrometry. In addition, as long as the measurement unit 31 measures a physical quantity that changes with the etching process, in addition to the absorption intensity, the emission amount or other physical quantities can also be measured.

[0066] In addition, as long as it does not violate the gist of the present invention, various modifications and combinations of the embodiments can also be made.

Claims

1. An endpoint detection device, characterized in that: Detection of the end point of etching processes in multilayer films, The endpoint detection device comprises: a measuring unit that measures a physical quantity that changes with the etching process; an endpoint detection unit that detects an endpoint of a film as a target for endpoint detection using a predetermined detection algorithm based on the measurement value obtained by the measurement unit; as well as An algorithm changing unit changes the detection algorithm of the film being etched based on a measurement value obtained by the measuring unit when etching was previously performed on other films of the same type as the target film in the same multilayer film as the target film being etched.

2. The endpoint detection device according to claim 1, characterized in that: The algorithm changing unit changes a detection threshold of the endpoint of the target film being subjected to the etching process.

3. The endpoint detection device according to claim 1 or 2, characterized in that: The end point detection unit calculates a transfer time between a transfer start point and a transfer end point of a film to be etched from a film being etched to a next film.

4. The endpoint detection device according to any one of claims 1 to 3, characterized in that: The algorithm changing unit changes the endpoint detection algorithm of the film being etched based on the measurement values ​​of two or more past measurements obtained by the measuring unit when etching was performed on other films of the same type as the film being etched and which are in the same multilayer film as the film being etched.

5. The endpoint detection device according to claim 4, characterized in that: The endpoint detection device further includes a data storage unit that stores relationship data indicating a relationship between a transition time between a transition start point and a transition end point in a measurement value obtained by the measurement unit when etching was previously performed on another film of the same type as the target film in the multilayer film that is the same as the target film being etched, and a slope of the measurement value during this period. The end point detection unit calculates the transition time from the film being etched to the next film based on the relationship data and the slope of the measurement value of the film being etched after the transition start point.

6. The endpoint detection device according to any one of claims 1 to 5, characterized in that: The end point detection device further includes a display control unit configured to display, on a display, a time-series change in the measurement value obtained by the measurement unit.

7. The endpoint detection device according to any one of claims 1 to 6, characterized in that: The measuring unit performs absorbance measurement on a reaction product generated by etching.

8. An etching control system, characterized in that: have: an etching control device that controls an etching processing device that performs an etching process on the multilayer film; as well as The endpoint detection device according to any one of claims 1 to 7, If the end point detection device detects a transfer start point indicating that the film being etched starts to transfer from the film being etched to the next film, the etching control device changes the etching procedure of the film being etched in the multi-layer film.

9. The etching control system according to claim 8, characterized in that: The etching control device changes the etching rate of the film in the multi-layer film that is being etched.

10. An endpoint detection method, characterized in that: Detection of the end point of etching processes in multilayer films, In the endpoint detection method, The measuring unit measures a physical quantity that changes with the etching process. detecting an endpoint of a target film for detecting an endpoint using a predetermined detection algorithm based on the measurement value obtained by the measurement unit, The detection algorithm of the film being etched is changed based on the measurement value obtained by the measurement unit when etching was previously performed on other films of the same type as the target film in the same multilayer film as the target film being etched.

11. A recording medium, characterized in that: It records an endpoint detection program used by an endpoint detection device for detecting an endpoint of a multilayer film in an etching process, wherein the endpoint detection program enables a computer to have: As a receiving unit, the receiving unit receives measurement value data from a measuring unit that measures changes caused by the etching process; As an endpoint detection unit, a function of detecting an endpoint of a film as a target for endpoint detection using a predetermined detection algorithm based on the measurement value obtained by the measurement unit; as well as The function of the algorithm changing unit is to change the detection algorithm of the film being etched based on the measurement value obtained by the measuring unit when etching was previously performed on other films of the same type as the target film and in the same multilayer film as the target film being etched.

Images