A method for measuring the removal width of a thin film layer at the edge of a wafer

Abstract

The present application discloses a method for measuring the removal width of a thin film layer at the edge of a wafer. The measurement method includes: providing a wafer formed with a pad thin film layer and a thin film layer to be monitored located on the pad thin film layer; performing edge removal treatment to expose a part of the pad thin film layer; measuring the thickness of the pad thin film layer at a plurality of measurement points and obtaining the goodness of fit corresponding to each measurement point; when the goodness of fit shows a jump, determining that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point; determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point. The present application measures the thickness of the pad thin film layer by a thin film thickness measuring instrument and obtains the corresponding goodness of fit, and determines the actual removal width of the thin film layer to be monitored through the goodness of fit and the position of the measurement point. The method is simple, has a low cost and high accuracy.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and more particularly to a method for measuring the removal width of a thin film layer at the edge of a wafer. Background Art

[0002] During the manufacturing process of semiconductor devices, after forming a thin film layer on a wafer, for example, forming a copper thin film layer by using the Electroless Copper Plating (ECP) process, there may be defects at the edge of the wafer. In order to improve the yield of the product, it is necessary to remove the thin film layer that may cause defects at the edge of the wafer. Usually, the Edge Bevel Removal (EBR) method is used to effectively remove the defective thin film layer. The accuracy of the removal width at the edge of the wafer is directly related to the number of defects and the size of the effective area of the wafer. Therefore, it is necessary to measure the removal width to make the removal width meet the preset standard, so as to ensure process stability and then ensure product quality.

[0003] In the related art, usually a professional optical measurement device is used for measurement or manual visual inspection is carried out. When measuring the removal width at the edge of the wafer by using an optical measurement device, the measurement device is expensive and the cost is high. When manually visually measuring the removal width at the edge of the wafer, the measurement result is prone to deviation due to human factors, and its accuracy cannot be guaranteed, and the accuracy of manual visual measurement is low. Summary of the Invention

[0004] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description section. The Summary of the Invention section of the present application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0005] In view of the existing problems, an embodiment of the present application provides a method for measuring the removal width of a thin film layer at the edge of a wafer, and the measurement method includes:

[0006] Providing a wafer, on which a pad thin film layer and a to-be-monitored thin film layer located on the pad thin film layer are formed;

[0007] Removing a part of the to-be-monitored thin film layer in the four peripheral edge regions of the wafer to expose a part of the pad thin film layer;

[0008] Measuring the thicknesses of the thin film layers at a plurality of measurement points in sequence from the edge of the wafer to the central region of the wafer, or from the central region of the wafer to the edge of the wafer by a thin film thickness measuring instrument, and obtaining the goodness of fit corresponding to each measurement point;

[0009] When there is a jump in the goodness of fit of the current measurement point compared to the goodness of fit of the previous measurement point, it is determined that the edge of the thin film layer to be monitored is between the current measurement point and the previous measurement point;

[0010] Based on the position information of the current measurement point and / or the position information of the previous measurement point, determine the actual removal width of the thin film layer to be monitored.

[0011] In some embodiments of the present application, the determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and the position information of the previous measurement point includes:

[0012] Based on the position information of the current measurement point, determine a first distance from the current measurement point to the center of the wafer;

[0013] Obtain the radius of the wafer, and determine a first removal width based on the difference between the radius of the wafer and the first distance;

[0014] Based on the position information of the previous measurement point, determine a second distance from the previous measurement point to the center of the wafer;

[0015] Based on the difference between the radius of the wafer and the second distance, determine a second removal width, and the actual removal width is between the first removal width and the second removal width.

[0016] In some embodiments of the present application, the determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point includes:

[0017] Based on the position information of the current measurement point, determine a first distance from the current measurement point to the center of the wafer;

[0018] Obtain the radius of the wafer, and determine a first removal width based on the difference between the radius of the wafer and the first distance, wherein when measuring from the edge of the wafer towards the central region of the wafer, the actual removal width is less than or equal to the first removal width, or when measuring from the central region of the wafer towards the edge of the wafer, the actual removal width is greater than or equal to the first removal width.

[0019] In some embodiments of the present application, the determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point includes:

[0020] Based on the position information of the previous measurement point, determine a second distance from the previous measurement point to the center of the wafer;

[0021] Determine a second removal width based on the difference between the radius of the wafer and the second distance, where when measuring from the edge of the wafer towards the central region of the wafer, the actual removal width is greater than or equal to the second removal width, or when measuring from the central region of the wafer towards the edge of the wafer, the actual removal width is less than or equal to the second removal width.

[0022] In some embodiments of the present application, the measurement method further includes:

[0023] Establish a coordinate system with any point on the wafer as the origin, and a plurality of the measurement points are arranged at intervals in a measurement direction that is 45° to the coordinate axes of the coordinate system.

[0024] In some embodiments of the present application, the origin is the center of the wafer.

[0025] In some embodiments of the present application, the thin film layer to be monitored is a metal layer, the metal layer includes copper, and the material of the cushion thin film layer includes tantalum.

[0026] In some embodiments of the present application, the metal layer is formed by a chemical copper plating process.

[0027] In some embodiments of the present application, when the goodness of fit of the current measurement point shows a jump compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.8.

[0028] In some embodiments of the present application, when the goodness of fit of the current measurement point decreases by at least 0.1 compared to the goodness of fit of the previous measurement point, it indicates that the goodness of fit of the current measurement point shows a jump compared to the goodness of fit of the previous measurement point.

[0029] The measurement method for the removal width of the thin film layer at the edge of the wafer provided by the present application is to perform edge trimming on the wafer formed with the cushion thin film layer and the thin film layer to be monitored to expose a part of the cushion thin film layer, then use a thin film thickness measuring instrument to measure the thickness of the cushion thin film layer and obtain the corresponding goodness of fit, determine the edge position of the thin film layer to be monitored through the value of the goodness of fit, and determine the actual removal width of the thin film layer to be monitored from the position information of the relevant measurement points, so as to achieve the purpose of measuring the removal width at the edge of the wafer only through the thin film thickness measuring instrument. The measurement method of the present application is simple, has a low cost, and the measurement result is relatively accurate. Description of the Drawings

[0030] The following drawings of the present application are used as a part of the present application to understand the present application. The embodiments of the present application shown in the drawings and their descriptions are used to explain the principles of the present application. In the drawings:

[0031] Figure 1Schematic flowchart of a method for measuring the removal width of a thin film layer at the wafer edge according to a specific embodiment of the present application;

[0032] Figures 2A - 2B Cross-sectional view showing the positional relationship among the cushion thin film layer, the thin film layer to be monitored, and the wafer during the edge removal process in the method for measuring the removal width of a thin film layer at the wafer edge according to a specific embodiment of the present application;

[0033] Figure 3 Shows the method for measuring the removal width of a thin film layer at the wafer edge according to a specific embodiment of the present application Figure 2B Top view schematic;

[0034] Figure 4 Top view showing the positional relationship between a current measurement point A and a previous measurement point B in the method for measuring the removal width of a thin film layer at the wafer edge according to a specific embodiment of the present application;

[0035] Figure 5 Top view showing another positional relationship between a current measurement point A and a previous measurement point B in the method for measuring the removal width of a thin film layer at the wafer edge according to a specific embodiment of the present application. Specific embodiments

[0036] In the following description, numerous specific details are given to provide a more thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application may be practiced without one or more of these details. In other instances, some well-known technical features are not described to avoid obscuring the present application.

[0037] It should be understood that the present application can be implemented in different forms and should not be construed as limited to the embodiments presented herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete, and to fully convey the scope of the present application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0038] It should be understood that when an element or layer is referred to as being "on", "adjacent to", "connected to" or "coupled to" another element or layer, it can be directly on, adjacent to, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on", "directly adjacent to", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or portions, these elements, components, regions, layers and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or portion from another element, component, region, layer or portion. Thus, a first element, component, region, layer or portion discussed below may be denoted as a second element, component, region, layer or portion without departing from the teachings of this application.

[0039] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. are used herein for convenience in describing the relationship of one element or feature shown in the figures to other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relationship terms are intended to also encompass different orientations of the device in use and operation. For example, if the device in the figures is flipped, then an element or feature described as "under" or "beneath" or "below" another element or feature will be oriented "on" the other element or feature. Thus, the exemplary terms "under" and "beneath" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or other orientations) and the spatial descriptors used herein are to be interpreted accordingly.

[0040] The purpose of the terms used herein is only to describe specific embodiments and is not a limitation of this application. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprising" and / or "including", when used in this specification, specify the presence of the stated features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups. As used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0041] During the manufacturing process of semiconductor devices, after forming a thin film layer on a wafer, such as forming a copper thin film layer using the electroplating copper process, the edge of the wafer may be uneven, and at the same time, metal or chemical substances may remain on the edge. The subsequent polishing process cannot handle the remaining metal or chemical substances on the wafer edge and inclined areas. These remaining metal or chemical substances may cause contamination to the subsequent process, thereby affecting the surface quality of the wafer and the performance of the device. In order to improve the product yield, it is necessary to remove the thin film layer that may cause defects on the wafer edge. Usually, the wafer edge removal method is used to effectively remove the defective thin film layer. The accuracy of the wafer edge removal width is directly related to the number of defects and the size of the effective area of the wafer. Therefore, it is necessary to measure the removal width to make the removal width meet the preset standard, thereby ensuring process stability and further ensuring product quality.

[0042] In the related art, a method for measuring the removal width of the wafer edge is completed by a professional optical AOI (Automated Optical Inspection) measuring device, or a module for measuring the removal width of the wafer edge is added to the ECP main platform. Specifically, the wafer defect inspection system with electron beam patterning can capture and identify wafer defects, and visually measure the removal width of the wafer edge. The equipment used in this method is expensive and has a high cost. In the absence of professional optical measuring equipment, a scale magnifying glass is usually used for manual visual inspection. Manual visual inspection will produce human errors and the accuracy cannot be guaranteed. The accuracy of manual visual measurement is low.

[0043] Therefore, in view of the existence of the foregoing technical problems, the embodiment of the present application proposes a method for measuring the removal width of the thin film layer on the wafer edge, as Figure 1 shown, which mainly includes the following steps:

[0044] Step S110: Provide a wafer, on which a pad thin film layer and a thin film layer to be monitored located on the pad thin film layer are formed;

[0045] Step S120: Remove a part of the thin film layer to be monitored in the four peripheral edge regions of the wafer to expose a part of the pad thin film layer;

[0046] Step S130: Measure the thickness of the thin film layer at multiple measurement points in sequence from the edge of the wafer to the central region of the wafer, or measure the thickness of the thin film layer at multiple measurement points in sequence from the central region of the wafer to the edge of the wafer by a thin film thickness measuring instrument, and obtain the goodness of fit corresponding to each measurement point;

[0047] Step S140: When there is a jump in the goodness of fit of the current measurement point compared to that of the previous measurement point, determine that the edge of the thin film layer to be monitored lies between the current measurement point and the previous measurement point;

[0048] Step S150: Based on the position information of the current measurement point and / or the position information of the previous measurement point, determine the actual removal width of the thin film layer to be monitored.

[0049] The method for measuring the removal width of the thin film layer at the edge of a wafer provided by the embodiments of the present application involves performing edge trimming on a wafer formed with a pad thin film layer and a thin film layer to be monitored to expose a part of the pad thin film layer, then using a thin film thickness measuring instrument to measure the thickness of the pad thin film layer and obtaining the corresponding goodness of fit. The edge position of the thin film layer to be monitored is determined by the value of the goodness of fit, and the actual removal width of the thin film layer to be monitored is determined by the position information of relevant measurement points. Thus, the purpose of measuring the removal width at the edge of the wafer can be achieved only by using a thin film layer thickness measuring instrument. The measurement method of the present application is simple, has a low cost, and the measurement result is relatively accurate.

[0050] Next, with reference to Figure 1 、 Figure 2A 、 Figure 2B and Figures 3 to 5 a detailed description will be given of the method for measuring the removal width of the thin film layer at the edge of the wafer according to the embodiments of the present application.

[0051] First, as Figure 1 shown, perform step S110 to provide a wafer on which a pad thin film layer and a thin film layer to be monitored located on the pad thin film layer are formed.

[0052] As Figure 2A shown, provide a wafer 200, form a pad thin film layer 201 on the wafer 200, and form a thin film layer 202 to be monitored on the pad thin film layer 201. It is worth mentioning that the edge of the pad thin film layer 201 can be located within the edge of the wafer 200, or it can be basically aligned with the edge of the wafer. In the present application, an embodiment in which the edge of the pad thin film layer 201 is basically aligned with the edge of the wafer 200 is used for illustration. Exemplarily, the thin film layer 202 to be monitored is a metal layer, and the metal layer includes but is not limited to copper (Cu), and the material of the pad thin film layer 201 includes but is not limited to Ta (tantalum). Exemplarily, the metal layer is formed by a chemical copper plating process.

[0053] Next, continuing as Figure 1 shown, perform step S120 to remove a part of the thin film layer 202 to be monitored in the peripheral edge region of the wafer 200 to expose a part of the pad thin film layer 201, obtaining the structure as Figure 2B shown. It is worth mentioning that the subsequent steps of the embodiments of the present application will be carried out in the structure as Figure 2BExecute on the structure shown.

[0054] Next, step S130 is executed. From the edge of the wafer 200 to the central region of the wafer 200 by a film thickness measuring instrument, or from the central region of the wafer 200 to the edge of the wafer 200 by a film thickness measuring instrument, measure the thickness of the film layer at multiple measurement points at predetermined intervals in sequence and obtain the goodness of fit corresponding to each of the measurement points. It is worth mentioning that when measuring the film layer thickness from the edge of the wafer 200 to the central region of the wafer 200 by a film thickness measuring instrument, the film layer is the cushion film layer 201. When measuring the film layer thickness from the central region of the wafer (the central region is also the region within the edge of the film layer 202 to be monitored) to the edge of the wafer 200 by a film thickness measuring instrument, the film layer is the film layer 202 to be monitored.

[0055] The goodness of fit (Good of fitness, GOF) is a value obtained by comparing the measured spectral fit with the actual measurement result. It is worth mentioning that there is a spectral value in the film thickness measuring instrument. This spectral value is multiplied by a gain coefficient in the film thickness measuring instrument to obtain the measured spectral fit. The film thickness measuring instrument can automatically calculate the goodness of fit corresponding to the measurement point based on the measured spectral fit and the actual measurement result of the measurement point. The goodness of fit can be obtained by any suitable method, and no specific limitation is made here.

[0056] Next, step S140 is executed. When there is a jump in the goodness of fit at the current measurement point compared to the goodness of fit at the previous measurement point, it is determined that the edge of the thin film layer to be monitored lies between the current measurement point and the previous measurement point. Exemplarily, when there is a jump in the goodness of fit at the current measurement point compared to the goodness of fit at the previous measurement point, the goodness of fit at the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.8. For example, the predetermined value is 0.8, 0.75, or 0.7. Exemplarily, when a thin film thickness measuring instrument measures the thickness of a thin film layer based on the thin film layer to be monitored, when there is a jump in the goodness of fit at the current measurement point compared to the goodness of fit at the previous measurement point, the goodness of fit at the current measurement point is greater than the predetermined value. In a specific example, the cushion thin film layer is a Ta thin film layer, and the thin film layer to be monitored is a copper layer. Since the substrate is metal Ta, the process recipe (i.e., measurement parameters) of the thin film thickness measuring instrument is configured with the relevant parameters of Ta. Starting from the first measurement point on the edge of the wafer 200, the thicknesses of the thin film layers at multiple measurement points are measured sequentially at a predetermined interval. Before the copper layer, the thin film thickness measuring instrument has been measuring only the thickness of the Ta thin film layer. Since the process recipe of the equipment is the relevant parameters of Ta, when there is only the Ta thin film layer, the relevant parameters of the process recipe match the actual thin film layer, and the measurement value is accurate, and the goodness of fit is high. When the copper layer is measured, the thin film thickness measuring instrument should actually use the relevant parameters of copper for thickness measurement calculation, but in this application, the calculation is still carried out with the relevant parameters of Ta. Therefore, at this time, there will be a jump in the goodness of fit calculated by the thin film thickness measuring instrument. Exemplarily, when the goodness of fit at the current measurement point decreases by at least 0.1 compared to the goodness of fit at the previous measurement point, it indicates that there is a jump in the goodness of fit at the current measurement point compared to the goodness of fit at the previous measurement point. When there is a jump in the goodness of fit, it means that the device has detected the relevant material of the thin film layer to be monitored, and there is a thin film layer to be monitored at this measurement point, that is, as Figure 2B and Figure 3 shown, the current measurement point is A, and the previous measurement point is B. At measurement point B, there is only the cushion thin film layer 201. At measurement point A, there are both the cushion thin film layer 201 and the thin film layer 202 to be monitored. Therefore, it can be determined that the edge of the thin film layer 202 to be monitored lies between the current measurement point and the previous measurement point.

[0057] Next, step S150 is executed to determine the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point. In some embodiments, the position information of the measurement point can be represented by a coordinate system and corresponding coordinates. Exemplarily, a coordinate system is established with an arbitrary point on the wafer as the origin, and multiple measurement points are arranged at intervals in a measurement direction that is 45° with respect to the coordinate axes of the coordinate system. Exemplarily, the origin is the center of the wafer. Arranging multiple measurement points at intervals in the measurement direction that is 45° with respect to the coordinate axes of the coordinate system can make the numerical values of the abscissa and ordinate of the measurement points equal, facilitating the determination of the actual removal width.

[0058] In some embodiments, determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and the position information of the previous measurement point includes: As Figure 3 shown, based on the position information of the current measurement point A, for example, the coordinates of point A, determine the first distance L1 from the current measurement point A to the center C of the wafer; obtain the radius R of the wafer, and determine the first removal width R - L1 based on the difference between the radius of the wafer and the first distance L1; based on the position information of the previous measurement point B, determine the second distance L2 from the previous measurement point B to the center C of the wafer; determine the second removal width R - L2 based on the difference between the radius R of the wafer and the second distance L2. Since multiple test points are set at a predetermined interval, when the first measurement point on the thin film layer to be monitored is measured, for the foregoing reasons, the GOF will have a jump. At this time, the current measurement point A is either on the edge of the thin film layer 202 to be monitored or on the side of the thin film layer 202 close to the center of the circle. Therefore, the actual removal width L is between the first removal width R - L1 and the second removal width R - L2. The specific position of the current measurement point A is related to the predetermined interval of the measurement points. The smaller the interval, the closer it is to the edge of the thin film layer 202 to be monitored, and the denser the measurement points are, the closer the first removal width R - L1 and the second removal width R - L2 are, and the more accurate the value of the actual removal width L is.

[0059] In some embodiments, when measuring from the edge of the wafer to the central region of the wafer by a thin film thickness measuring instrument, as Figure 4As shown, when the predetermined interval is large, based on the position information of the current measurement point A, the actual removal width L of the thin film layer 202 to be monitored is determined, including: based on the position information of the current measurement point A, determining a first distance L1 from the current measurement point A to the center C of the wafer; obtaining the radius R of the wafer, and determining a first removal width R - L1 based on the difference between the radius R of the wafer and the first distance L1, then the actual removal width L is less than or equal to the first removal width R - L1. When the current measurement point A is exactly at the edge of the thin film layer 202 to be monitored and the previous measurement point B is also exactly at the edge of the cushion thin film layer 201, the actual removal width L is equal to the first removal width R - L1. Similarly to the above calculation method, when measuring from the central region of the wafer to the edge of the wafer with a thin film thickness measuring instrument, when the current measurement point is outside the thin film layer to be monitored, the actual removal width is greater than or equal to the first removal width. When the current measurement point is extremely close to the edge of the thin film layer to be monitored, it can be considered that the actual removal width is equal to the first removal width. The specific calculation process is not elaborated here.

[0060] In some embodiments, when measuring from the edge of the wafer to the central region of the wafer with a thin film thickness measuring instrument, as Figure 5 shown, when the predetermined interval is large and the previous measurement point B is close to the thin film layer 202 to be monitored, based on the position information of the current measurement point A and / or the position information of the previous measurement point B, the actual removal width L of the thin film layer 202 to be monitored is determined, including: based on the position information of the previous measurement point B, determining a second distance L2 from the previous measurement point B to the center C of the wafer, determining a second removal width R - L2 based on the difference between the radius R of the wafer and the second distance L2, the actual removal width L is greater than or equal to the second removal width R - L2. The closer the previous measurement point B is to the edge of the thin film layer 202 to be monitored, the closer the actual removal width L is to the second removal width R - L2. Similarly to the above calculation method, when measuring from the central region of the wafer to the edge of the wafer with a thin film thickness measuring instrument, when the current measurement point is outside the thin film layer to be monitored and on the cushion thin film layer, and the previous measurement point is inside the thin film layer to be monitored, the actual removal width is less than or equal to the second removal width. When the previous measurement point is extremely close to the edge of the thin film layer to be monitored and the current measurement point is extremely close to the edge of the cushion thin film layer, it can be considered that the actual removal width is equal to the second removal width. The specific calculation process is not elaborated here.

[0061] Generally, when the actual removal width is within the predetermined range of the removal width, it can be determined that the actual removal width meets the standard. For example, if the predetermined range of the removal width is 2.5 mm ± 0.5 mm, then when the actual removal width is between 2.0 mm and 3.0 mm, it is considered that the actual removal width meets the standard.

[0062] In some embodiments, the range of the predetermined width for removal may also correspond to a range of radial dimensions, that is, the range of radial dimension values corresponding to the edge of the thin film layer 202 to be monitored. Then, based on the position information of the current measurement point and / or the position information of the previous measurement point, the radial dimension of the current measurement point (i.e., the aforementioned first distance) and the radial dimension of the previous measurement point (i.e., the aforementioned second distance) are determined. When the first distance and the second distance are within the range of the radial dimension, it can be determined that the width for removal meets the predetermined standard; if it exceeds the range of the radial dimension, it does not meet the predetermined standard.

[0063] Thus far, the description of the method for measuring the removal width of the thin film layer at the edge of a wafer according to an embodiment of the present application has been completed. It can be understood that the method for measuring the removal width of the thin film layer at the edge of the wafer in this embodiment not only includes the above steps, but may also include other necessary steps before, during, or after the above steps, and all of them are included within the scope of the measurement method in this embodiment.

[0064] The method for measuring the removal width of the thin film layer at the edge of a wafer provided by the embodiment of the present application performs edge trimming on the wafer formed with a cushion thin film layer and the thin film layer to be monitored to expose a part of the cushion thin film layer, then measures the thickness of the cushion thin film layer using a thin film thickness measuring instrument and obtains the corresponding goodness of fit, determines the edge position of the thin film layer to be monitored based on the value of the goodness of fit, and determines the actual removal width of the thin film layer to be monitored from the position information of relevant measurement points. Thus, the purpose of measuring the removal width at the edge of the wafer can be achieved only by using a thin film thickness measuring instrument. The measurement method of the present application is simple, has a low cost, and the measurement result is relatively accurate.

[0065] It should be noted that the above embodiments illustrate the present application rather than limit the present application, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application can be implemented by means of hardware including several different elements and by means of a computer appropriately programmed. In the claims listing several units of a vehicle-mounted system, several of these vehicle-mounted systems can be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names.

[0066] The above is only the specific implementation manner or the description of the specific implementation manner of the present application. The protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should be covered within the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for measuring the width of a wafer edge thin film layer removed, characterized in that: include: Providing a wafer, on which a liner film layer and a film layer to be monitored located on the liner film layer are formed, the film layer to be monitored is a metal layer, and the liner film layer is substantially aligned with an edge of the wafer; Removing part of the film layer to be monitored in the peripheral edge area of ​​the wafer to expose part of the liner film layer; Using a film thickness measuring instrument, measuring the thickness of the film layer at a plurality of measuring points from the edge of the wafer to the center of the wafer, or measuring the thickness of the film layer at a plurality of measuring points from the center of the wafer to the edge of the wafer at predetermined intervals, and obtaining the goodness of fit corresponding to each of the measuring points; When the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, it is determined that the edge of the film layer to be monitored is between the current measurement point and the previous measurement point, wherein the jump in the goodness of fit indicates that the film thickness measuring instrument has detected the relevant material of the film layer to be monitored; Based on the position information of the current measuring point and / or the position information of the previous measuring point, the actual removal width of the thin film layer to be monitored is determined.

2. The measuring method according to claim 1, characterized in that: The determining the actual removal width of the thin film layer to be monitored based on the position information of the current measuring point and the position information of the previous measuring point includes: Determine a first distance from the current measurement point to the center of the wafer based on the position information of the current measurement point; Acquire the radius of the wafer, and determine a first removal width based on a difference between the radius of the wafer and the first distance; Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, and the actual removal width is between the first removal width and the second removal width.

3. The measuring method according to claim 1, characterized in that: The determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point includes: Determine a first distance from the current measurement point to the center of the wafer based on the position information of the current measurement point; The radius of the wafer is obtained, and a first removal width is determined based on a difference between the radius of the wafer and the first distance, wherein the actual removal width is less than or equal to the first removal width when measured from the edge of the wafer to the center area of ​​the wafer, or the actual removal width is greater than or equal to the first removal width when measured from the center area of ​​the wafer to the edge of the wafer.

4. The measuring method according to claim 1, characterized in that: Determining the actual removal width of the thin film layer to be monitored based on the position information of the current measurement point and / or the position information of the previous measurement point includes: Determine a second distance from the previous measurement point to the center of the wafer based on the position information of the previous measurement point; A second removal width is determined based on a difference between a radius of the wafer and the second distance, wherein the actual removal width is greater than or equal to the second removal width when measured from the edge of the wafer to the center area of ​​the wafer, or the actual removal width is less than or equal to the second removal width when measured from the center area of ​​the wafer to the edge of the wafer.

5. The measuring method according to claim 1, characterized in that: The measuring method further comprises: A coordinate system is established with any point on the wafer as the origin, and the plurality of measuring points are arranged at intervals in a measuring direction at an angle of 45° to the coordinate axis of the coordinate system.

6. The measuring method according to claim 5, characterized in that: The origin is the center of the wafer.

7. The measuring method according to claim 1, characterized in that: The metal layer includes copper, and the material of the pad film layer includes tantalum.

8. The measuring method according to claim 7, characterized in that: The metal layer is formed by a chemical copper electroplating process.

9. The measuring method according to claim 1, characterized in that: When the goodness of fit of the current measurement point jumps compared to the goodness of fit of the previous measurement point, the goodness of fit of the current measurement point is less than a predetermined value, and the predetermined value is less than or equal to 0.

8.

10. The measuring method according to claim 1, characterized in that: When the goodness of fit of the current measurement point decreases by at least 0.1 compared with the goodness of fit of the previous measurement point, it means that a jump occurs in the goodness of fit of the current measurement point compared with the goodness of fit of the previous measurement point.

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