Semiconductor etching monitoring method, device and equipment and storage medium

Abstract

The embodiment of the invention relates to the field of semiconductor etching, and discloses a semiconductor etching monitoring method, device and equipment and a storage medium, and the method comprises the steps: determining a spectral vector of each pixel point in spectral image data of a wafer; a pixel point of the etching layer is selected and determined as a first reference pixel point, and a spectral vector corresponding to the first reference pixel point is determined as a first reference vector; performing similarity comparison on a spectral vector of each pixel point in the spectral image data and a first reference vector, and determining a distribution area of an etching layer and a termination layer in the spectral image data; aiming at the distribution area of the stop layer, selecting a spectral band range meeting a preset condition from the plurality of spectral bands to be determined as a characteristic spectral band of the stop layer; and monitoring the etching end point of the to-be-etched wafer based on the characteristic spectrum section of the stop layer. The problem of inaccurate monitoring of the etching end point in an actual process is solved, the etching end point is monitored according to the characteristic spectrum section of the stop layer, and the accuracy of monitoring the etching end point is improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor technology, and in particular to a semiconductor etching monitoring method, device, equipment and storage medium. Background Art

[0002] In the semiconductor manufacturing process, a common method for forming patterns on the wafer surface is to perform a photolithography + etching process, in which the photolithography process "imprints" the required pattern from the mask plate to the photoresist layer, and then the etching process transfers it to the wafer surface.

[0003] For semiconductor etching process, "aspect ratio" is an important process parameter. There are usually two ways to control the etching depth. One is to collect the film thickness and etching rate, and convert them into the etching time by theoretical conversion, and then adjust them several times to get the best main process time; the other is to set the film end point and monitor it in the actual process. When the product is etched to this position, the process stops.

[0004] However, in the actual process, due to the complexity of the chip, changes in the film material or machine contamination and other issues, it is easy to cause inaccurate monitoring of the etching endpoint, and even "over-etching" may occur, resulting in product scrapping. Summary of the invention

[0005] The purpose of the present invention is to at least provide a semiconductor etching monitoring method, device, equipment and storage medium, which can at least solve the problem of inaccurate etching endpoint monitoring caused by chip complexity, film material changes or machine contamination in actual processes, and even "over-etching" leading to product scrapping. At least the etching endpoint can be monitored according to the characteristic spectrum of the termination layer, thereby improving the accuracy of etching endpoint monitoring.

[0006] To solve the above technical problems, at least one embodiment of the present application provides a semiconductor etching monitoring method, comprising: acquiring spectral image data of a wafer after etching, wherein the spectral image data includes image data of an etching layer and a stop layer in the wafer under multiple spectral bands;

[0007] Determining a spectral vector of each pixel in the spectral image data of the wafer;

[0008] A pixel point of the etching layer is selected as a first reference pixel point, and a spectral vector corresponding to the first reference pixel point is determined as a first reference vector;

[0009] Comparing the similarity of the spectral vector of each pixel point in the spectral image data with the first reference vector, and determining the distribution area of ​​the etching layer and the termination layer in the spectral image data;

[0010] With respect to the distribution area of ​​the termination layer, a spectral band range that meets a preset condition is selected from a plurality of spectral bands, and the spectral band range that meets the preset condition is determined as a characteristic spectral band of the termination layer;

[0011] Based on the characteristic spectrum of the stop layer, the etching endpoint of the wafer to be etched is monitored.

[0012] At least one embodiment of the present application further provides a semiconductor etching monitoring device, comprising: an image acquisition component, an imaging component, a filtering component and a control unit;

[0013] The control unit is used to obtain spectral image data of the etched wafer through an image acquisition component, an imaging component and a filtering component, wherein the spectral image data includes image data of the etching layer and the termination layer in the wafer under multiple spectral bands; determine the spectral vector of each pixel point in the spectral image data of the wafer; select a pixel point of the etching layer as a first reference pixel point, and determine the spectral vector corresponding to the first reference pixel point as a first reference vector; compare the spectral vector of each pixel point in the spectral image data with the first reference vector for similarity, and determine the distribution area of ​​the etching layer and the termination layer in the spectral image data; for the distribution area of ​​the termination layer, select a spectral band range that meets preset conditions from multiple spectral bands, and determine the spectral band range that meets the preset conditions as the characteristic spectrum band of the termination layer; based on the characteristic spectrum band of the termination layer, monitor the etching endpoint of the wafer to be etched.

[0014] At least one embodiment of the present application further provides a semiconductor etching monitoring device, comprising an acquisition module, for acquiring spectral image data of a wafer after etching, wherein the spectral image data comprises image data of an etching layer and a stop layer in the wafer under multiple spectral bands;

[0015] A vector determination module, used to determine the spectral vector of each pixel point in the spectral image data of the wafer;

[0016] A reference selection module, used for selecting a pixel point of the etching layer as a first reference pixel point, and determining a spectral vector corresponding to the first reference pixel point as a first reference vector;

[0017] A comparison module, used for comparing the similarity of the spectral vector of each pixel point in the spectral image data with the first reference vector, and determining the distribution area of ​​the etching layer and the termination layer in the spectral image data;

[0018] A spectrum band determination module, for selecting a spectrum band range that meets preset conditions from a plurality of spectrum bands for a distribution area of ​​the termination layer, and determining the spectrum band range that meets the preset conditions as a characteristic spectrum band of the termination layer;

[0019] The monitoring module is used to monitor the etching endpoint of the wafer to be etched based on the characteristic spectrum of the stop layer.

[0020] At least one embodiment of the present application also provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned semiconductor etching monitoring method.

[0021] At least one embodiment of the present application further provides a computer-readable storage medium storing a computer program, wherein the computer program implements the above-mentioned semiconductor etching monitoring method when executed by a processor.

[0022] The semiconductor etching monitoring method, device, equipment and storage medium provided by the embodiments of the present application, after obtaining the spectral image data of the etching layer and the termination layer in the wafer after etching, determine the spectral vector of each pixel point in the spectral image data of the wafer, select a pixel point of the etching layer as the first reference pixel point, and determine the spectral vector corresponding to the first reference pixel point as the first reference vector, and then compare the spectral vector of each pixel point in the spectral image data with the first reference vector for similarity, and determine the distribution area of ​​the etching layer and the termination layer in the spectral image data. Then, for the distribution area of ​​the termination layer, select a spectral band range that meets the preset conditions from multiple spectral bands, and determine the spectral band range that meets the preset conditions as the characteristic spectral band of the termination layer, and then monitor the etching end point of the wafer to be etched based on the characteristic spectral band of the termination layer. In this way, by acquiring the characteristic spectrum of the stop layer, the etching endpoint of the wafer is monitored in a targeted manner according to the characteristic spectrum of the stop layer, which effectively reduces the probability of inaccurate etching endpoint monitoring and even "over-etching" leading to product scrapping due to problems such as chip complexity, film material changes or machine contamination in the actual process.

[0023] In some optional embodiments, the step of determining the spectral vector of each pixel in the spectral image data of the wafer includes: determining the grayscale value of the pixel in the etching layer under each spectral band as the spectral intensity of the pixel in the etching layer; determining the spectral intensity of the pixel in the etching layer under multiple spectral bands as the spectral vector of each pixel in the etching layer; determining the grayscale value of the pixel in the termination layer under each spectral band as the spectral intensity of the pixel in the termination layer; determining the spectral intensity of the pixel in the termination layer under multiple spectral bands as the spectral vector of each pixel in the termination layer. By determining the spectral vectors of the etching layer and the termination layer, it is convenient to monitor the etching endpoint of the wafer to be etched after subsequent data processing.

[0024] In some optional embodiments, the step of performing a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector to determine the distribution area of ​​the etching layer and the termination layer in the spectral image data includes: performing a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector to determine a similarity comparison value; detecting whether the similarity comparison value is within a preset matching range; when the similarity comparison value is within the preset matching range, determining that the pixel points whose similarity comparison values ​​are within the preset matching range are the pixel points of the etching layer, and the remaining pixel points are the pixel points of the termination layer. By performing a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector, the film layer where the pixel point is located is determined, thereby distinguishing the distribution area of ​​the etching layer and the termination layer.

[0025] In some optional embodiments, the step of selecting a spectral band range that meets the preset conditions from a plurality of spectral bands for the distribution area of ​​the termination layer, and determining the spectral band range that meets the preset conditions as the characteristic spectral band of the termination layer includes: calculating the pixel points in the distribution area of ​​the termination layer of each spectral band to determine the average value of the termination spectrum intensity of each spectral band; detecting whether the average value of the termination spectrum intensity is greater than the preset light intensity threshold; when the average value of the termination spectrum intensity is greater than the preset light intensity threshold, selecting a spectral band whose average value of the termination spectrum intensity is greater than the preset light intensity threshold from a plurality of spectral bands, thereby obtaining the spectral band range of the termination layer; determining the spectral band range of the termination layer as the characteristic spectral band of the termination layer. By acquiring the characteristic spectral band of the termination layer, the etching endpoint of the wafer is monitored in a targeted manner according to the characteristic spectral band of the termination layer, which effectively reduces the probability of inaccurate monitoring of the etching endpoint and even "over-etching" leading to product scrapping in the actual process due to problems such as complex chips, changes in film material or machine contamination.

[0026] In some optional embodiments, the method further includes: for the distribution area of ​​the etching layer, selecting a spectral band range that meets preset conditions from a plurality of spectral bands, and determining the spectral band range that meets the preset conditions as the characteristic spectral band of the etching layer; the step of monitoring the etching endpoint of the wafer to be etched based on the characteristic spectral band of the termination layer includes: monitoring the etching endpoint of the wafer to be etched based on the characteristic spectral band of the termination layer and the characteristic spectral band of the etching layer. After determining the characteristic spectral band of the etching layer and the characteristic spectral band of the termination layer, the characteristic spectral band of the etching layer and the characteristic spectral band of the termination layer can be monitored in a targeted manner, which can further improve the accuracy of monitoring the etching endpoint of the wafer to be etched.

[0027] In some optional embodiments, the etching layer includes an engraved area and a reserved area; the method further includes: selecting a pixel point in the engraved area in the etching layer as a second reference pixel point, and determining the spectral vector corresponding to the second reference pixel point as a second reference vector; comparing the spectral vector of each pixel point in the spectral image data with the second reference vector for similarity, and determining the distribution area of ​​the engraved area, the reserved area and the termination layer in the spectral image data. After determining the characteristic spectral band of the engraved area, the characteristic spectral band of the reserved area and the characteristic spectral band of the termination layer, the characteristic spectral band of the engraved area, the characteristic spectral band of the reserved area and the characteristic spectral band of the termination layer can be monitored in a targeted manner, which can not only improve the etching accuracy when etching the engraved area, but also further improve the accuracy of etching endpoint monitoring of the wafer to be etched. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] One or more embodiments are exemplarily described by the pictures in the corresponding drawings, and these exemplary descriptions do not constitute limitations on the embodiments.

[0029] Figure 1 It is a flow chart of a semiconductor etching monitoring method provided by an embodiment of the present application;

[0030] Figure 2 is a structural block diagram of a semiconductor etching monitoring device in one embodiment of the present application;

[0031] Figure 3 is a structural schematic diagram of an electronic device provided by another embodiment of the present application;

[0032] Figure 4 is a schematic flow chart of a semiconductor etching monitoring method in another embodiment of the present application;

[0033] Figure 5 is a schematic diagram of an etching layer and a stop layer provided by an embodiment of the present application;

[0034] Figure 6is a structural schematic diagram of a semiconductor etching monitoring device provided by another embodiment of the present application;

[0035] Figure 7 It is a schematic diagram of a filter component in a semiconductor etching monitoring device provided in another embodiment of the present application. DETAILED DESCRIPTION

[0036] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not be construed as any limitation, and the various embodiments can be combined and referenced with each other under the premise of no contradiction.

[0037] In order to facilitate understanding of the embodiments of the present application, relevant contents about the semiconductor etching monitoring method are first introduced here.

[0038] In the semiconductor manufacturing process, a common method for forming patterns on the wafer surface is to perform a photolithography + etching process, in which the photolithography process "imprints" the required pattern from the mask plate to the photoresist layer, and then the etching process transfers it to the wafer surface.

[0039] For semiconductor etching process, "aspect ratio" is an important process parameter. There are usually two ways to control the etching depth. One is to collect the film thickness and etching rate, and convert them into the etching time by theoretical conversion, and then adjust them several times to get the best main process time; the other is to set the film end point and monitor it in the actual process. When the product is etched to this position, the process stops.

[0040] However, in the actual process, due to the complexity of the chip, changes in the film material or machine contamination and other issues, it is easy to cause inaccurate monitoring of the etching endpoint, and even "over-etching" may occur, resulting in product scrapping.

[0041] In order to solve the above-mentioned technical problem that in the actual process, due to the complexity of the chip, the change of the film material or the pollution of the machine, the etching endpoint monitoring is easily inaccurate, and even "over-etching" may occur, resulting in the product being scrapped, the present invention proposes a semiconductor etching monitoring method. The implementation details of the semiconductor etching monitoring method of this embodiment are specifically described below. The following content is only the implementation details provided for the convenience of understanding, and is not necessary for the implementation of this solution.

[0042] Embodiment 1:

[0043] The semiconductor etching monitoring method of this embodiment can be applied to electronic devices with communication, computing and data storage capabilities. The specific process can be as follows: Figure 1 As shown, including:

[0044] Step 101 : acquiring spectral image data of a wafer after etching, wherein the spectral image data includes image data of an etching layer and a stop layer in the wafer under multiple spectral bands.

[0045] Specifically, the etched wafer is used as a sample, and the spectral image data of the etched wafer is obtained through a microscopic hyperspectral camera to obtain the spectral image data of the etched layer and the termination layer in the wafer. Among them, the spectral image refers to a set of images obtained by collecting the wafer under different spectral bands. The spectral image data can not only show the spatial relationship of objects in the plane, but also show the relationship between the details of the object and the wavelength of light, so as to facilitate the distinction of substances.

[0046] Step 102 : determining a spectral vector of each pixel point in the spectral image data of the wafer.

[0047] Specifically, in the semiconductor manufacturing process, the materials of the etching layer and the mask are usually fixed. The material of the etching layer is metal, SiO2, Si3N4, etc. The mask material is usually photoresist. The material of the termination layer is different from that of the etching layer. These objects will form an emission spectrum after being irradiated by a light source or after etching glow discharge. In this embodiment, for an object of a certain material, any pixel point of the substance in the spectral image data is selected to obtain the spectral vector of the pixel point in multiple spectral bands. Repeat the above operation to obtain the spectral vector of each pixel point in the spectral image data of the wafer.

[0048] Step 103: Select a pixel point of the etching layer as a first reference pixel point, and determine a spectrum vector corresponding to the first reference pixel point as a first reference vector.

[0049] Specifically, a pixel point of the etching layer is selected in the spectral image data to be determined as the first reference pixel point. Furthermore, pixels with clear details and features are preferentially selected in the selection of the first reference pixel point. After the first reference pixel point is determined, the spectral vector corresponding to the first reference pixel point is determined as the first reference vector. It should be noted that, since the spectral vector of each pixel point in the spectral image data of the wafer has been obtained in step 102, in this embodiment, the spectral vector corresponding to the first reference pixel point can be directly obtained and determined as the first reference vector.

[0050] Step 104 : performing a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector to determine the distribution areas of the etching layer and the stop layer in the spectral image data.

[0051] Specifically, the first reference vector is the reference vector of the first reference pixel point of the etching layer. When the spectral vector of each pixel point in the spectral image data is compared with the first reference vector for similarity, that is, when comparing which pixels in the spectral image data belong to the pixels of the etching layer, after determining the pixels belonging to the etching layer, the pixels other than the pixels of the etching layer are the pixels of the termination layer, thereby distinguishing the distribution areas of the etching layer and the termination layer.

[0052] In some examples, the first reference vector is denoted as X. The first reference vectors in different spectral bands form a vector subset. When the total number of spectral bands is n, the vector subset has n elements. The similarity between the spectral vector of each pixel in the spectral image data and the first reference vector is compared by the following relationship:

[0053]

[0054] Where X is the first reference vector, Y is the spectral vector of a pixel in the spectral image data, and X i is the vector subset of the first reference vector, Y i is a vector subset of the spectral vector of a certain pixel point in the spectral image data, and D is a similarity comparison value of comparing the spectral vector of each pixel point in the spectral image data with the first reference vector.

[0055] In some examples, when the material of the etching layer is SiO2, a pixel point of the etching layer is selected as the first reference pixel point, and the first reference pixel point is a reference pixel point selected in the etching layer whose material is SiO2. By obtaining the spectral vector of the first reference pixel point in multiple spectral bands, and comparing the spectral vector of each pixel point in the spectral image data with the first reference vector for similarity, it can be determined which pixels in the spectral image data belong to SiO2, that is, which pixels belong to the etching layer.

[0056] Step 105 , with respect to the distribution area of ​​the termination layer, a spectral band range that meets a preset condition is selected from a plurality of spectral bands, and the spectral band range that meets the preset condition is determined as a characteristic spectral band of the termination layer.

[0057] Specifically, after determining the distribution area of ​​the etching layer and the termination layer, a preset condition is set, and according to the distribution area of ​​the termination layer, a spectral band that meets the preset condition is selected from multiple spectral bands, and the spectral band that meets the preset condition is used as the spectral band range, and then the spectral band range is used as the characteristic spectral band of the termination layer. It should be noted that the spectral band range includes one spectral band and may also include multiple spectral bands. When the spectral band range includes one spectral band, the spectral band is the spectral band range of the termination layer. When the spectral band range includes multiple spectral bands, the multiple spectral bands are integrated, and the integrated spectral band is used as the spectral band range of the termination layer.

[0058] Step 106 , monitoring the etching endpoint of the wafer to be etched based on the characteristic spectrum of the stop layer.

[0059] Specifically, after determining the characteristic spectrum of the stop layer, the characteristic spectrum of the stop layer can be monitored in a targeted manner, so that when etching the wafer to be etched, the etching endpoint of the wafer to be etched can be monitored according to the characteristic spectrum of the stop layer. Compared with the existing etching endpoint identification method, it not only reduces the amount of calculation data required for etching endpoint monitoring, but also effectively reduces the probability of inaccurate etching endpoint monitoring and even "over-etching" leading to product scrapping in actual processes due to problems such as complex chips, changes in film material or machine contamination.

[0060] In some examples, the photolithography pattern can be used as a reference image and compared with the spectral image under the characteristic spectrum of the termination layer to further determine the location of the etching residue and improve the accuracy of etching endpoint monitoring.

[0061] In some examples, after determining the characteristic spectrum of the termination layer of a certain material, the characteristic spectrum of the termination layer of the material can be sorted and summarized so as to be directly reused in the subsequent etching endpoint monitoring process of the same type of wafer, thereby improving the utilization rate of data. When the material of the termination layer of the wafer changes, the operation of steps 101 to 106 needs to be repeated to obtain the characteristic spectrum of the termination layer after the material changes.

[0062] In this embodiment, after obtaining the spectral image data of the etching layer and the termination layer in the wafer after etching, the spectral vector of each pixel in the spectral image data of the wafer is determined, a pixel of the etching layer is selected as the first reference pixel, and the spectral vector corresponding to the first reference pixel is determined as the first reference vector, and then the spectral vector of each pixel in the spectral image data is compared with the first reference vector for similarity, and the distribution area of ​​the etching layer and the termination layer in the spectral image data is determined. Then, for the distribution area of ​​the termination layer, a spectral band range that meets the preset conditions is selected from a plurality of spectral bands, and the spectral band range that meets the preset conditions is determined as the characteristic spectrum of the termination layer, and then based on the characteristic spectrum of the termination layer, the etching endpoint of the wafer to be etched is monitored. In this way, by acquiring the characteristic spectrum of the termination layer, the etching endpoint of the wafer is monitored according to the characteristic spectrum of the termination layer in a targeted manner, which effectively reduces the probability of inaccurate monitoring of the etching endpoint and even the occurrence of "over-etching" leading to product scrapping in the actual process due to problems such as complex chips, changes in film material or machine pollution.

[0063] In some embodiments, the step of determining the spectral vector of each pixel point in the spectral image data of the wafer includes:

[0064] Determine the gray value of the pixel point in the etching layer under each spectral band as the spectral intensity of the pixel point in the etching layer;

[0065] Determine the spectral intensity of the pixel points in the etching layer under multiple spectral bands as the spectral vector of each pixel point in the etching layer;

[0066] The gray value of the pixel point in the termination layer under each spectral band is determined as the spectral intensity of the pixel point in the termination layer;

[0067] The spectral intensity of the pixel points in the termination layer under multiple spectral bands is determined as the spectral vector of each pixel point in the termination layer.

[0068] Specifically, for a certain material object, any pixel point of the material in the spectral image data is selected, and the grayscale value of the pixel point in a certain spectral band is read as the spectral intensity of the pixel point in the spectral band, and then the next spectral band is switched to, and the grayscale value of the pixel point in the next spectral band is read again as the spectral intensity of the pixel point in the next spectral band, so that the spectral vector of the pixel point in multiple spectral bands can be obtained by repeating the above steps in the order of wavelengths. In this embodiment, for the etching layer, a pixel point of the etching layer in the spectral image data is selected, and the grayscale value of the pixel point in a certain spectral band is read as the spectral intensity of the pixel point in the spectral band, and then the next spectral band is switched to, and the grayscale value of the pixel point in the next spectral band is read again as the spectral intensity of the pixel point in the next spectral band, so that the spectral vector of the pixel point in the etching layer in multiple spectral bands can be obtained by repeating the above steps in the order of wavelengths, and then the spectral intensity of the pixel point in the etching layer in multiple spectral bands is determined as the spectral vector of each pixel point in the etching layer. For the termination layer, select the pixel point of the etching layer in the spectral image data, read the gray value of the pixel point in a certain spectral band as the spectral intensity of the pixel point in the spectral band, then switch to the next spectral band, read the gray value of the pixel point in the next spectral band again as the spectral intensity of the pixel point in the next spectral band, and repeat the above steps in the order of wavelength to obtain the spectral vector of the pixel point in the termination layer in multiple spectral bands, and then determine the spectral intensity of the pixel point in the termination layer in multiple spectral bands as the spectral vector of each pixel point in the termination layer. By determining the spectral vectors of the etching layer and the termination layer, it is convenient to monitor the etching endpoint of the wafer to be etched after subsequent data processing. It should be noted that the determination of the spectral vectors of the etching layer and the termination layer can be carried out simultaneously.

[0069] In some embodiments, the step of comparing the spectral vector of each pixel point in the spectral image data with the first reference vector for similarity and determining the distribution area of ​​the etching layer and the termination layer in the spectral image data includes:

[0070] Performing a similarity comparison between the spectral vector of each pixel in the spectral image data and the first reference vector to determine a similarity comparison value;

[0071] Detect whether the similarity comparison value is within a preset matching range;

[0072] When the similarity comparison value is within the preset matching range, it is determined that the pixel points whose similarity comparison value is within the preset matching range are the pixel points of the etching layer, and the remaining pixel points are the pixel points of the termination layer.

[0073] Specifically, the spectral vector of each pixel in the spectral image data is compared with the first reference vector for similarity through the relationship (1) to obtain a similarity comparison value. When the similarity comparison value corresponding to a certain pixel is high, it means that the pixel is similar to the first reference pixel. In this embodiment, it is detected whether the similarity comparison value is within the preset matching range. When the similarity comparison value is within the preset matching range, the pixel points whose similarity comparison values ​​are within the preset matching range are determined to be the pixel points of the etching layer, and the remaining pixel points are the pixel points of the termination layer, so as to distinguish the distribution areas of the etching layer and the termination layer.

[0074] In some examples, the preset matching range is set to (0.85, 1). When the similarity comparison value obtained by comparing the spectral vector of a pixel point in the spectral image data with the first reference vector falls into (0.85, 1), it means that the pixel point is similar to the first reference pixel point, and the pixel point belongs to the pixel point of the etching layer.

[0075] In some examples, when the material of the etching layer is SiO2, a pixel point of the etching layer is selected as the first reference pixel point, and the first reference pixel point is a reference pixel point selected in the etching layer whose material is SiO2. The SiO2 curve is formed by acquiring the spectral vector of the first reference pixel point in multiple spectral bands, and the spectral vector of a pixel point in the spectral image data in multiple spectral bands forms a comparison curve. The SiO2 curve is matched with the comparison curve. When the similarity comparison value of the two falls into (0.85, 1), it indicates that both belong to SiO2, that is, the pixel point belongs to the pixel point of the etching layer.

[0076] In some embodiments, based on the distribution area of ​​the termination layer, the step of selecting a spectral band range that meets preset conditions from a plurality of spectral bands, and determining the spectral band range that meets the preset conditions as a characteristic spectral band of the termination layer includes:

[0077] Calculate the pixel points in the distribution area of ​​the termination layer of each spectral band to determine the average value of the termination spectrum intensity of each spectral band;

[0078] Detect whether the average value of the termination spectrum intensity is greater than a preset light intensity threshold;

[0079] When the average value of the termination spectrum intensity is greater than the preset light intensity threshold, a spectrum band whose average value of the termination spectrum intensity is greater than the preset light intensity threshold is selected from multiple spectrum bands, thereby obtaining a spectrum band range of the termination layer;

[0080] The spectral band range of the termination layer is determined as the characteristic spectral band of the termination layer.

[0081] Specifically, after determining the distribution area of ​​the termination layer, the spectral intensity of each pixel point in the distribution area of ​​the termination layer under each spectral band is summed to obtain the sum of the regional spectral intensity values ​​under each spectral band. When calculating the average value of the termination spectrum intensity of each spectral band, it is calculated by the following relationship: average termination spectrum intensity = sum of regional spectral intensity values / number of regional pixels.

[0082] In this embodiment, after determining the average value of the termination spectrum intensity of each spectral band, it is detected whether the average value of the termination spectrum intensity is greater than the preset light intensity threshold. When the average value of the termination spectrum intensity is greater than the preset light intensity threshold, a spectral band whose average value of the termination spectrum intensity is greater than the preset light intensity threshold is selected from multiple spectral bands, thereby obtaining the spectral band range of the termination layer, and determining the spectral band range of the termination layer as the characteristic spectrum band of the termination layer. In this way, the etching endpoint of the wafer is monitored in a targeted manner according to the characteristic spectrum band of the termination layer, effectively reducing the probability of inaccurate etching endpoint monitoring caused by problems such as complex chips, changes in film material or machine contamination in actual processes, and even the probability of "over-etching" leading to product scrapping.

[0083] In some examples, when the average intensity value of a certain area in the spectral image is greater than 0.75, the brightness and darkness transition is obviously higher than that of other areas, and therefore, the preset light intensity threshold is set to 0.75. When the average value of the termination spectrum intensity is greater than 0.75, a spectrum band with an average value of the termination spectrum intensity greater than 0.75 is selected from multiple spectrum bands to obtain the spectrum band range of the termination layer, and the spectrum band range of the termination layer is determined as the characteristic spectrum band of the termination layer.

[0084] In some embodiments, the semiconductor etching monitoring method further includes:

[0085] For the distribution area of ​​the etching layer, a spectral band range that meets the preset conditions is selected from multiple spectral bands, and the spectral band range that meets the preset conditions is determined as a characteristic spectral band of the etching layer;

[0086] Based on the characteristic spectrum of the stop layer, the steps of monitoring the etching endpoint of the wafer to be etched include:

[0087] Based on the characteristic spectrum of the stop layer and the characteristic spectrum of the etching layer, the etching endpoint of the wafer to be etched is monitored.

[0088] Specifically, after determining the distribution areas of the etching layer and the termination layer, the average etching spectrum intensity in the distribution area of ​​the termination layer under each spectral band is determined according to the distribution area of ​​the etching layer, and then it is detected whether the average etching spectrum intensity is greater than the preset light intensity threshold. When the average etching spectrum intensity is greater than the preset light intensity threshold, a spectral band whose average etching spectrum intensity is greater than the preset light intensity threshold is selected from multiple spectral bands, so as to obtain the spectral band range of the etching layer, and the spectral band range of the etching layer is determined as the characteristic spectral band of the etching layer.

[0089] In this embodiment, after determining the characteristic spectrum of the etching layer and the characteristic spectrum of the stop layer, the characteristic spectrum of the etching layer and the characteristic spectrum of the stop layer can be monitored in a targeted manner, which can further improve the accuracy of etching endpoint monitoring for the etched wafer.

[0090] In some embodiments, the etching layer includes an etched area and a reserved area;

[0091] The method also includes:

[0092] A pixel point in the engraved area of ​​the etching layer is selected as a second reference pixel point, and a spectral vector corresponding to the second reference pixel point is determined as a second reference vector;

[0093] The spectral vector of each pixel point in the spectral image data is compared with the second reference vector for similarity, and the distribution areas of the carved area, the reserved area and the termination layer in the spectral image data are determined.

[0094] Specifically, the etching layer includes an engraved area and a reserved area. The engraved area is used to be etched to a specified depth according to a specified shape, and the surface of the reserved area is covered by a mask (mostly photoresist) to prevent the etching layer covered by the mask from being etched. Since the surface of the reserved area is covered by a mask, in the spectral image, the material of the reserved area and the engraved area is different. The material presented in the reserved area is the material of the mask, such as photoresist, while the material of the engraved area is the material of the etching layer itself, such as metal, SiO2, and Si3N4.

[0095] In this embodiment, a pixel point of the engraved area in the etching layer is selected in the spectral image data to be determined as the second reference pixel point. After the second reference pixel point is determined, the spectral vector corresponding to the second reference pixel point is determined as the second reference vector. It should be noted that, since the spectral vector of each pixel point in the spectral image data of the wafer has been obtained in step 102, in this embodiment, the spectral vector corresponding to the second reference pixel point can be directly obtained and determined as the second reference vector. The second reference vector is the reference vector of the second reference pixel point of the engraved area in the etching layer. When the spectral vector of each pixel point in the spectral image data is compared with the second reference vector for similarity, that is, which pixels in the spectral image data belong to the pixels of the engraved area in the etching layer are compared. After the pixels belonging to the engraved area in the etching layer are determined, the pixels of the etching layer obtained by the similarity comparison according to the first reference vector are combined. The pixels in the etching layer other than the pixels in the engraved area are the pixels of the reserved area, and the pixels other than the pixels in the etching layer are the pixels of the termination layer, thereby distinguishing the distribution areas of the engraved area, the reserved area and the termination layer.

[0096] In some examples, the similarity comparison value of the spectral vector of each pixel in the spectral image data and the second reference vector can also be calculated by using the relation (1). At this time, in this embodiment, X in the relation (1) is the second reference vector, Y is the spectral vector of a pixel in the spectral image data, and X i is the vector subset of the second reference vector, Y i is a vector subset of the spectral vector of a certain pixel point in the spectral image data, and D is a similarity comparison value for comparing the spectral vector of each pixel point in the spectral image data with the second reference vector.

[0097] In some examples, when the material of the etching layer is SiO2, a pixel point in the engraving area of ​​the etching layer is selected as the second reference pixel point, and the second reference pixel point is a reference pixel point selected in the engraving area whose material is SiO2. By obtaining the spectral vector of the second reference pixel point in multiple spectral bands, and comparing the spectral vector of each pixel point in the spectral image data with the second reference vector for similarity, it can be determined which pixels in the spectral image data belong to SiO2, that is, which pixels belong to the engraving area.

[0098] In some examples, after determining the distribution areas of the engraved area, the reserved area, and the termination layer, the average etching spectrum intensity in the distribution area of ​​the engraved area under each spectral band is determined according to the distribution area of ​​the engraved area, and then it is detected whether the average etching spectrum intensity is greater than a preset light intensity threshold. When the average etching spectrum intensity is greater than the preset light intensity threshold, a spectral band whose average etching spectrum intensity is greater than the preset light intensity threshold is selected from multiple spectral bands, thereby obtaining the spectral band range of the engraved area, and determining the spectral band range of the engraved area as the characteristic spectral band of the engraved area. According to the distribution area of ​​the reserved area, the average etching spectrum intensity in the distribution area of ​​the reserved area under each spectral band is determined, and then it is detected whether the average etching spectrum intensity is greater than the preset light intensity threshold. When the average etching spectrum intensity is greater than the preset light intensity threshold, a spectral band whose average etching spectrum intensity is greater than the preset light intensity threshold is selected from multiple spectral bands, thereby obtaining the spectral band range of the reserved area, and determining the spectral band range of the reserved area as the characteristic spectral band of the reserved area.

[0099] In this embodiment, after determining the characteristic spectral bands of the engraving area, the characteristic spectral bands of the reserved area, and the characteristic spectral bands of the termination layer, the characteristic spectral bands of the engraving area, the characteristic spectral bands of the reserved area, and the characteristic spectral bands of the termination layer can be monitored in a targeted manner, which can not only improve the etching accuracy when etching the engraving area, but also further improve the accuracy of etching endpoint monitoring of the wafer to be etched.

[0100] Embodiment 2:

[0101] On the basis of the first embodiment, this embodiment further provides a semiconductor etching monitoring device, which is used in the semiconductor etching monitoring method in the first embodiment. The semiconductor etching monitoring device of this embodiment includes: an image acquisition component, an imaging component, a filtering component and a control unit;

[0102] The control unit is used to obtain spectral image data of the etched wafer through an image acquisition component, an imaging component and a filtering component, wherein the spectral image data includes image data of the etching layer and the termination layer in the wafer under multiple spectral bands; determine the spectral vector of each pixel point in the spectral image data of the wafer; select a pixel point of the etching layer as a first reference pixel point, and determine the spectral vector corresponding to the first reference pixel point as a first reference vector; perform a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector to determine the distribution area of ​​the etching layer and the termination layer in the spectral image data; for the distribution area of ​​the termination layer, select a spectral band range that meets preset conditions from multiple spectral bands, and determine the spectral band range that meets the preset conditions as a characteristic spectral band of the termination layer; based on the characteristic spectral band of the termination layer, monitor the etching end point of the wafer to be etched.

[0103] Specifically, the image acquisition component can be a variable-focus high-definition industrial camera that can achieve grayscale imaging with a maximum resolution of 1920*1080 16-bit, while ensuring an imaging rate of 3 frames per second. The imaging component includes an objective lens and a lens group. The objective lens combined with the focusing function of the industrial camera can achieve a 5-10x magnification function. The lens group is used for optical path collimation to facilitate the control of light focusing and transmission. The filter component consists of a replaceable filter chip group combined with a carrier mechanism, such as Figure 7 As shown in the figure, the filter chip set is designed to be square, arranged in a 3*3 layout, and placed on the surface of the carrier mechanism. The chip is designed to be a bandpass filter, and each chip corresponds to a spectral band of the substance. In actual application, the filter component is placed in front of the image acquisition component. Before the light enters the camera, it will first pass through the filter component. After being split by the filter chip in the filter component, it will be imaged on the surface of the industrial camera. The result is the spectral image of the target to be measured.

[0104] In some examples, during actual application, one defect usually corresponds to multiple filter chips. Therefore, the semiconductor etching monitoring equipment also includes a driving component. The driving component uses a micro-drive motor connected to the filter component to drive the filter component to move, control channel switching, and combine with industrial camera shooting to realize automatic data collection of all spectral bands. The filter component cooperates with the driving component: that is, in the initial position, the industrial camera lens is aimed at the first filter chip; after completing the shooting of a spectral image, the driving component drives the filter component to step to the next chip. This cycle repeats until the data collection of all filter chips is completed.

[0105] Specifically, the control unit uses a conventional MCU or programmable logic chip as the main control. After programming, it can control image acquisition, channel switching, and drive components to cooperate with each other to achieve automatic acquisition of 3 frames per second. In addition, the control unit can perform image consistency calculations to compare the consistency of the results obtained by the industrial camera with the actual chip layout.

[0106] When the film layer (etching layer and termination layer) is misidentified, the "pseudo-defect" is removed by the local contrast method, and the final position of the defect is determined. Specifically, for the defective image with misidentification, the edge extraction algorithm in the field of image processing is used for edge extraction. The edge extraction algorithm can be a convolution algorithm or a Sobel algorithm to obtain the edge position data of each defect inside the scene. Then, the local contrast in each area is calculated, and the calculation is performed through the following relationship: local contrast = sum of grayscale values ​​of pixels in the area / total number of pixels. Then, the area with a local contrast higher than a certain threshold is selected as the defective area. In some examples, it is more appropriate to set the local contrast threshold to 0.75-0.85. In this way, the probability of misidentification of the film layer (etching layer and termination layer) is effectively reduced.

[0107] This application is aimed at the etching process of semiconductor manufacturing, and can realize real-time and rapid monitoring of the end point of the etching layer. The present invention is mainly based on the principle of spectral imaging, and uses the differences in components within the substance to distinguish substances, which can effectively identify the film layers containing O, N or obtained by unconventional processes in the semiconductor manufacturing process. In addition, unlike conventional light reflection spectrum and other monitoring schemes, this scheme utilizes the reflection characteristics of the substance itself. As long as there are differences in components inside the substance, its reflection spectrum must be different, and it is only necessary to calculate the different spectral segment positions. At the same time, a major feature of this scheme is: single acquisition, long-term use. That is, the obtained material spectrum segment data is summarized and can be directly called for later use, avoiding repeated operations.

[0108] Embodiment three:

[0109] This embodiment provides exemplary contents of Embodiment 1 and Embodiment 2, that is, provides an exemplary process of a semiconductor etching monitoring method and a semiconductor etching monitoring device, and the specific contents include:

[0110] like Figure 5 As shown, the mask for semiconductor etching is usually photoresist, which is structurally composed of an open area (i.e., an immediate open area) and a reserved area to form the required pattern. The non-open area (i.e., the reserved area) is used to block the area from being etched, and the open area will be etched to a specified depth and morphology. When a certain layer of the wafer is etched, as long as a reasonable etching stop layer is set, the film layer at the corresponding position of the open area will be etched clean, which also makes the other film layer at the bottom of the area exposed. In the semiconductor manufacturing process, the components of the etched film layer and the mask are usually fixed. The etched film layer (engraved open area) is such as metal, SiO2, Si3N4, etc., and the mask component is usually photoresist. These objects will form an emission spectrum after being irradiated by a light source or after etching glow discharge. Theoretically, the emission spectra produced by substances with different compositions must also be different, so it is only necessary to find the spectral position that can distinguish different substances to achieve component distinction. This is also the most commonly used solution for endpoint monitoring of etching processes. Objects are distinguished by monitoring the spectral information of gas by-products in the process under glow discharge, which is also called optical emission spectroscopy.

[0111] The monitoring method described in this scheme is also based on the reflectance spectrum of the material, but it does not rely entirely on the spectral differences of the material. Instead, it takes all the materials in the scene as the analysis objects, uses the spectral differences to find the characteristic spectrum segments that can distinguish each object at the image level, and presents them in the form of images. This method is more intuitive, efficient, and not prone to errors. When the amount of data collected is sufficient, this method can achieve real-time and high-precision monitoring of the stop layer of the etching process.

[0112] like Figure 4 As shown in FIG. 1 , the overall process of the method described in this scheme is divided into the following steps:

[0113] S1. Data collection

[0114] Data collection needs to be completed using a microscopic hyperspectral camera. The sample collected is an etched wafer, and finally a series of spectral images of the etched area and the retained area on the wafer surface are obtained. The so-called spectral image refers to a set of images obtained by collecting the same scene under different spectral bands. Such data can not only show the spatial relationship of objects in the plane, but also show the relationship between the details of the object and the wavelength of light, which is convenient for material differentiation. The data is arranged in the order of light wavelength to obtain a set of two-dimensional plane combined with spectral dimension data cube. As shown in the attached figure Figure 2 As shown, the data that needs to be collected include: the film in the engraved area, the film in the reserved area, and other locations of the non-current film layer. The spectral camera should have sufficient spatial resolution and spectral resolution. Taking silicon wafer etching with a minimum line width of 1um as an example, the camera parameters are selected with a spatial resolution of 2048*2048, an objective lens of 5 to 50 times, and a spectral resolution of 2.8nm as the best.

[0115] The spectrum described in this scheme is a visible light reflection spectrum with a wavelength of 400 to 720 nm.

[0116] S2. Target recognition and labeling

[0117] The data needs to be further analyzed to calculate the corresponding position relationship of different types of film layers in the image, so as to obtain the position information of the edges of objects of different materials. The purpose of this is to be able to correspond the spectral information with the material of the object, which is convenient for the subsequent characteristic spectrum calculation.

[0118] Objects of different materials are distinguished by spectral curves. The data collection step obtains spectral images of different bands at the same position, and only needs to use a suitable algorithm to classify and mark the data. The present invention uses a vector matching method to classify data, and the specific process is: spectral vector reading, target matching calculation, and target marking.

[0119] 1) Spectral vector reading. For a certain material object, select any pixel point of the material in the spectral image, and read the gray value of the point, which is the spectral intensity of the material in this band; then switch to the same position in the next band and read the gray point again; repeat the above steps in the order of wavelengths to obtain a set of spectral vectors.

[0120] 2) Target matching calculation. Select any pixel point in the engraved area in the spectral image (preferably a pixel with clear details and features), and record it as the reference vector X, X iis a vector subset of the reference vector. When the total number of bands is n, the subset has n elements. The reference vector and other vectors are compared by similarity using equation (1) to obtain a similarity comparison value. In this embodiment, in equation (1), X is the reference vector, Y is the spectral vector of a certain pixel point, and X i is a vector subset of the base vector, Y i is a vector subset of the spectral vector of a certain pixel. The closer the similarity comparison value is to 1, the higher the similarity between the two. For example, if a spectral image contains materials such as SiO2, Si, and photoresist, the SiO2 curve is used for target matching. When the matching degree between the two curves is between 0.85 and 1, it can be judged that the two belong to SiO2.

[0121] By performing this calculation on the film in the engraved area, the film in the reserved area, and other positions of the non-current film layer (i.e., the termination layer), the distribution range of all substances in the image can be obtained.

[0122] S3. Calculation of characteristic spectrum

[0123] The band range with strong average spectral intensity value is selected as the characteristic spectral band. Usually, when the average intensity value of a certain area in the picture is greater than 0.75, its brightness and darkness will be obviously higher than other areas, so the threshold range can be set to above 0.75. The calculation method of the average spectral intensity value is: the sum of the regional spectral intensity values / the number of regional pixels.

[0124] At this point, the characteristic spectral band positions of the etched area and the reserved area on the surface of a wafer can be obtained through calculation. Then, when identifying the etching stop layer, it is only necessary to monitor the corresponding spectral band in a targeted manner, which can greatly reduce the amount of calculated data.

[0125] In addition, the plate used for lithography can be used as a reference image and compared with the image taken under the characteristic spectrum band. The accuracy can be further improved by comparing the consistency.

[0126] At the same time, after the data is collected and calculated once, the results can be uniformly organized and summarized, and directly reused in the subsequent monitoring process. If the film layer on the wafer surface changes, such as SiO2 changes to Si3N4, then only one more collection and calculation is required to collect the data, which improves the utilization rate of the data.

[0127] In some embodiments, Figure 6 As shown, the semiconductor etching monitoring equipment should include: an image acquisition component, an imaging component, a filtering component, a driving component, and a computing component.

[0128] The image acquisition component is designed as a variable-focus high-definition industrial camera, which can achieve grayscale imaging with a maximum resolution of 1920*1080 16-bit, and can ensure an imaging rate of 3 frames per second. The imaging component includes an objective lens and a lens group. The objective lens combined with the focusing function of the industrial camera can achieve a 5-10x magnification function. The lens group is used for optical path collimation to facilitate the control of light focusing and transmission. The filter component is the core part of the device, which consists of a replaceable filter chipset combined with a carrier mechanism. Figure 7 As shown in the figure, the filter chip set is designed to be square, arranged in a 3*3 layout, and placed on the surface of the carrier. The chip is designed to be a bandpass filter, and each chip corresponds to a characteristic band of the substance. In actual application, the filter component is placed in front of the image acquisition component. Before the light enters the camera, it will first pass through the filter component, and after being split by the filter chip, it will be imaged on the camera surface. The result is the characteristic band imaging image of the target to be measured.

[0129] In actual applications, one defect usually corresponds to multiple filter chips, so the filter component usually cooperates with the drive component: that is, in the initial position, the camera lens is aimed at the first filter chip; after completing a photo shooting, the drive module immediately drives the filter module to step to the next chip. This cycle repeats until data collection of all filter chips is completed.

[0130] The driving component adopts a micro-driving motor connected to the filter component to drive the movement of the filter component, control channel switching, and combine with camera shooting to realize automatic collection of all characteristic band data.

[0131] The computing component (also called the control unit) uses a conventional MCU or programmable logic chip as the main control. After programming, it can control image acquisition, channel switching, and drive components to cooperate with each other to achieve automatic acquisition of 3 frames per second. In addition, the computing component can perform image consistency calculations to compare the consistency of the results obtained by the camera with the actual chip layout.

[0132] The local contrast method removes "pseudo defects" and determines the final position of the defect. The specific calculation method is: 1. For defective images, edge extraction algorithms in the field of image processing are used for edge extraction. The edge extraction algorithm can be a convolution algorithm or a Sobel algorithm to obtain the edge position data of each defect inside the scene; 2. Calculate the local contrast in each area. The calculation method is: local contrast = the sum of the grayscale values ​​of the pixels in the area / the total number of pixels; 3. Select the area with a local contrast higher than a certain threshold, which is the defect area. According to the author's experiment, it is more appropriate to set the local contrast threshold to 0.75-0.85.

[0133] Embodiment 4:

[0134] Another embodiment of the present application relates to a semiconductor etching monitoring device. The implementation details of the semiconductor etching monitoring device of this embodiment are specifically described below. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. The schematic diagram of the semiconductor etching monitoring device of this embodiment can be as follows Figure 2 As shown, a semiconductor etching monitoring device comprises:

[0135] An acquisition module 201 is used to acquire spectral image data of the wafer after etching, wherein the spectral image data includes image data of the etching layer and the stop layer in the wafer under multiple spectral bands;

[0136] A vector determination module 202 is used to determine a spectral vector of each pixel in the spectral image data of the wafer;

[0137] A reference selection module 203 is used to select a pixel point of the etching layer as a first reference pixel point, and determine a spectral vector corresponding to the first reference pixel point as a first reference vector;

[0138] A comparison module 204 is used to compare the spectral vector of each pixel point in the spectral image data with the first reference vector for similarity, and determine the distribution area of ​​the etching layer and the termination layer in the spectral image data;

[0139] The spectrum band determination module 205 is used to select a spectrum band range that meets the preset conditions from multiple spectrum bands according to the distribution area of ​​the termination layer, and determine the spectrum band range that meets the preset conditions as the characteristic spectrum band of the termination layer;

[0140] The monitoring module 206 is used to monitor the etching endpoint of the wafer to be etched based on the characteristic spectrum of the stop layer.

[0141] It is worth mentioning that all modules involved in this embodiment are logic modules. In practical applications, a logic unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. In addition, in order to highlight the innovative part of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed by this application, but this does not mean that there are no other units in this embodiment.

[0142] Embodiment five:

[0143] Another embodiment of the present application relates to an electronic device, such as Figure 3As shown, it includes: at least one processor 901; and a memory 902 that is communicatively connected to the at least one processor 901; wherein the memory 902 stores instructions that can be executed by the at least one processor 901, and the instructions are executed by the at least one processor 901 so that the at least one processor 901 can execute the semiconductor etching monitoring method in the above-mentioned embodiments.

[0144] Among them, the memory and the processor are connected in a bus manner, and the bus may include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors and memories together. The bus can also connect various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The data processed by the processor is transmitted on a wireless medium via an antenna, and further, the antenna also receives data and transmits the data to the processor.

[0145] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory can be used to store data used by the processor when performing operations.

[0146] Embodiment six:

[0147] Another embodiment of the present application relates to a computer-readable storage medium storing a computer program, which implements the above method embodiment when executed by a processor.

[0148] That is, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including a number of instructions to enable a device (which can be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as: ROM), random access memory (Random Access Memory, referred to as: RAM), disk or optical disk and other media that can store program codes.

[0149] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present application, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present application.

Claims

1. A semiconductor etching monitoring method, characterized in that: include: Acquire spectral image data of the wafer after etching, wherein the spectral image data includes image data of the etching layer and the stop layer in the wafer under multiple spectral bands; Determining a spectral vector of each pixel in the spectral image data of the wafer; A pixel point of the etching layer is selected as a first reference pixel point, and a spectral vector corresponding to the first reference pixel point is determined as a first reference vector; Comparing the similarity of the spectral vector of each pixel point in the spectral image data with the first reference vector, and determining the distribution area of ​​the etching layer and the termination layer in the spectral image data; With respect to the distribution area of ​​the termination layer, a spectral band range that meets a preset condition is selected from a plurality of spectral bands, and the spectral band range that meets the preset condition is determined as a characteristic spectral band of the termination layer; Based on the characteristic spectrum of the stop layer, the etching endpoint of the wafer to be etched is monitored.

2. The semiconductor etching monitoring method according to claim 1, characterized in that: The step of determining the spectral vector of each pixel point in the spectral image data of the wafer comprises: Determine the grayscale value of the pixel point in the etching layer under each spectral band as the spectral intensity of the pixel point in the etching layer; Determine the spectral intensity of the pixel points in the etching layer under multiple spectral bands as the spectral vector of each pixel point in the etching layer; Determine the gray value of the pixel point in the termination layer under each spectral band as the spectral intensity of the pixel point in the termination layer; The spectral intensity of the pixel point in the termination layer under multiple spectral bands is determined as the spectral vector of each pixel point in the termination layer.

3. The semiconductor etching monitoring method according to claim 1, characterized in that: The step of comparing the similarity of the spectral vector of each pixel point in the spectral image data with the first reference vector to determine the distribution area of ​​the etching layer and the termination layer in the spectral image data comprises: Performing a similarity comparison between the spectral vector of each pixel point in the spectral image data and the first reference vector to determine a similarity comparison value; Detecting whether the similarity comparison value is within a preset matching range; When the similarity comparison value is within a preset matching range, it is determined that the pixel points whose similarity comparison value is within the preset matching range are the pixel points of the etching layer, and the remaining pixel points are the pixel points of the termination layer.

4. The semiconductor etching monitoring method according to claim 1, characterized in that: The step of selecting a spectral band range that meets preset conditions from a plurality of spectral bands for the distribution area of ​​the termination layer, and determining the spectral band range that meets the preset conditions as a characteristic spectral band of the termination layer comprises: Calculating the pixel points in the distribution area of ​​the termination layer in each spectral band to determine the average termination spectrum intensity of each spectral band; Detecting whether the average value of the termination spectrum intensity is greater than a preset light intensity threshold; When the average value of the termination spectrum intensity is greater than a preset light intensity threshold, a spectrum band whose average value of the termination spectrum intensity is greater than the preset light intensity threshold is selected from the plurality of spectrum bands, thereby obtaining a spectrum band range of the termination layer; The spectral band range of the termination layer is determined as the characteristic spectral band of the termination layer.

5. The semiconductor etching monitoring method according to claim 1, characterized in that: The method further comprises: For the distribution area of ​​the etching layer, a spectral band range that meets the preset conditions is selected from a plurality of spectral bands, and the spectral band range that meets the preset conditions is determined as a characteristic spectral band of the etching layer; The step of monitoring the etching endpoint of the wafer to be etched based on the characteristic spectrum of the stop layer comprises: Based on the characteristic spectrum of the stop layer and the characteristic spectrum of the etching layer, the etching endpoint of the wafer to be etched is monitored.

6. The semiconductor etching monitoring method according to any one of claims 1 to 5, characterized in that: The etching layer includes an etched area and a reserved area; The method further comprises: A pixel point of the engraved area in the etching layer is selected as a second reference pixel point, and a spectral vector corresponding to the second reference pixel point is determined as a second reference vector; The spectral vector of each pixel point in the spectral image data is compared with the second reference vector for similarity, so as to determine the distribution areas of the engraved area, the reserved area and the termination layer in the spectral image data.

7. A semiconductor etching monitoring device, characterized in that: include: Image acquisition component, imaging component, filtering component and control unit; The control unit is used to obtain spectral image data of the etched wafer through an image acquisition component, an imaging component and a filtering component, wherein the spectral image data includes image data of the etching layer and the stop layer in the wafer under multiple spectral bands; determine the spectral vector of each pixel point in the spectral image data of the wafer; select a pixel point of the etching layer as a first reference pixel point, and determine the spectral vector corresponding to the first reference pixel point as a first reference vector; The spectral vector of each pixel point in the spectral image data is compared with the first reference vector for similarity to determine the distribution area of ​​the etching layer and the termination layer in the spectral image data; for the distribution area of ​​the termination layer, a spectral band range that meets preset conditions is selected from multiple spectral bands, and the spectral band range that meets the preset conditions is determined as the characteristic spectral band of the termination layer; based on the characteristic spectral band of the termination layer, the etching endpoint of the wafer to be etched is monitored.

8. A semiconductor etching monitoring device, characterized in that: include: An acquisition module, used for acquiring spectral image data of the wafer after etching, wherein the spectral image data includes image data of the etching layer and the stop layer in the wafer under multiple spectral bands; A vector determination module, used to determine the spectral vector of each pixel point in the spectral image data of the wafer; A reference selection module, used for selecting a pixel point of the etching layer as a first reference pixel point, and determining a spectral vector corresponding to the first reference pixel point as a first reference vector; A comparison module, used for comparing the similarity of the spectral vector of each pixel point in the spectral image data with the first reference vector, and determining the distribution area of ​​the etching layer and the termination layer in the spectral image data; A spectrum band determination module, for selecting a spectrum band range that meets preset conditions from a plurality of spectrum bands for a distribution area of ​​the termination layer, and determining the spectrum band range that meets the preset conditions as a characteristic spectrum band of the termination layer; The monitoring module is used to monitor the etching endpoint of the wafer to be etched based on the characteristic spectrum of the stop layer.

9. An electronic device, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the semiconductor etching monitoring method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the semiconductor etching monitoring method according to any one of claims 1 to 7 is implemented.

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