Visual display method for semiconductor mask defect detection

Abstract

The invention discloses a visual display method for defect detection of a semiconductor mask, and the method comprises the following steps: carrying out defect detection on the mask, and converting a defect position obtained by defect detection into a corresponding coordinate in a mask design drawing, namely a defect coordinate; generating a GDS file according to a design data file of the mask design drawing and the obtained defect coordinates; opening the GDS file by adopting an EDA (Electronic Design Automation) tool in an offline state so as to simultaneously superpose and display the mask design drawing corresponding to the database file layer and the defect corresponding to the defect data layer; according to the defect coordinates in the defect data layer, the positioning of the defect where the defect coordinates are located in the mask design drawing is checked in the window, and whether the defect has actual influence or not is judged. Through the method, detection and confirmation personnel can find the global position of the defect on the semiconductor mask and well judge whether the current defect actually influences the wafer or not, so that the product yield and the accuracy are improved.

Description

Technical Field

[0001] The invention relates to a visual display method for detecting defects of semiconductor masks. Background Art

[0002] At present, in the process of defect detection of semiconductor masks, the DIE to DB inspection mode is generally used for detection, that is, the actual mask produced in the end is compared with the mask design file GDS to identify defects. After the initial inspection is completed, it is often necessary to manually re-inspect the defect results, which is generally divided into two methods: online and offline. Online means that after the defect detection is completed, the high-power lens is used again on the AOI inspection equipment (the semiconductor mask is still on the equipment) to locate the defect position for confirmation. Offline means that after the AOI inspection equipment completes the inspection, the defect map is confirmed.

[0003] However, both of the above solutions have certain defects. The online method easily occupies the production capacity of AOI inspection equipment and is not easy to analyze defects again later. At the same time, since multiple semiconductor masks are required in the wafer manufacturing process, the offline solution is not convenient for preparing to know the location of the mask where the current defect is located and determine whether it will eventually affect the wafer, and can only analyze the mask corresponding to a certain layer of pattern. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a visual display method for semiconductor mask defect detection. Through this method, detection and confirmation personnel can find the global position of defects on the semiconductor mask and judge whether the current defects actually affect the wafer, so as to improve product yield and accuracy.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a method for visualizing defects in semiconductor mask inspection, the method comprising the following steps:

[0006] S1: Perform defect detection on the mask, and convert the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing, that is, the defect coordinates;

[0007] S2: Generate a GDS file from the design database file of the mask design drawing and the obtained defect coordinates; wherein the design database file forms a database file layer of the GDS file, and the defect coordinates form a defect data layer of the GDS file;

[0008] S3: Open the GDS file using an EDA tool in an offline state to simultaneously overlay and display the mask design corresponding to the database file layer and the defects corresponding to the defect data layer;

[0009] S4: Through the defect coordinates in the defect data layer, check the location of the defect where the defect coordinates are located in the mask design drawing in the window to determine whether the defect has actual impact.

[0010] Further, in step S1, the defect position obtained by defect detection is converted into corresponding coordinates in the mask design drawing, that is, the defect coordinates include:

[0011] Obtain the minimum enclosing rectangle of the defect contour by calculation;

[0012] Calibrate the coordinates of the rectangle and use the coordinates of the rectangle as the defect coordinates.

[0013] Calibrate the coordinates of a corner of the rectangle as the coordinates of the rectangle.

[0014] Furthermore, in step S4, the defect coordinates in the defect data layer are displayed in a list, and after a certain defect coordinate is selected, the actual location of the defect of the current defect coordinate in the mask design drawing is displayed in the window.

[0015] Furthermore, the determination of whether the defect has a practical impact is as follows:

[0016] By changing the viewport of the display window to display the details of the defect or the periphery of the defect on the mask design, the impact of the defect can be determined.

[0017] Further, step S1 is specifically as follows: selecting the DIE to DB inspection mode on the AOI inspection equipment, selecting the corresponding mark point to locate the semiconductor mask, and then performing defect detection, and converting the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing based on the mark point, that is, the defect coordinates.

[0018] After adopting the above technical solution, the present invention has the following beneficial effects:

[0019] 1. By directly outputting defects to the corresponding GDS file, the defect on a certain layer of mask can be accurately evaluated through superimposed display to see whether it affects the final chip;

[0020] 2. The method of the present invention has a high production capacity. The method of the present invention can confirm defects in an offline manner and will not occupy the time for AOI inspection equipment to be used for inspection.

[0021] 3. Since the method of the present invention can combine the defect results with the design drawings, it can have a very clear understanding of the nearby structure of the defect, that is, the surrounding graphics of the defect, and can well confirm the impact of the defect and improve the readiness of defect confirmation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a certain part of the mask design diagram in the present invention;

[0023] Figure 2 It is a schematic diagram showing a certain part of the mask design diagram in the present invention together with a defect; wherein the square is a schematic diagram of the defect;

[0024] Figure 3 A schematic diagram of expanding the field of view with a defect at a certain location of the mask design diagram in the present invention;

[0025] Figure 4 A schematic diagram of scribing to a certain location in the mask design diagram of the present invention;

[0026] Figure 5 It is a list of defect data in the defect data layer in the present invention. DETAILED DESCRIPTION

[0027] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0028] like Figures 1 to 5 As shown, a method for visualizing defects in semiconductor mask inspection includes the following steps:

[0029] S1: Perform defect detection on the mask, and convert the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing, that is, the defect coordinates;

[0030] S2: Generate a GDS file from the design database file of the mask design drawing and the obtained defect coordinates; wherein the design database file forms a database file layer of the GDS file, and the defect coordinates form a defect data layer of the GDS file;

[0031] S3: Open the GDS file using an EDA tool in an offline state to simultaneously overlay and display the mask design corresponding to the database file layer and the defects corresponding to the defect data layer. Figure 2 As shown, Figure 1 What is shown is a certain part of the mask design;

[0032] S4: Through the defect coordinates in the defect data layer, check the location of the defect where the defect coordinates are located in the mask design drawing in the window to determine whether the defect has actual impact.

[0033] Specifically, in step S1, the defect position obtained by defect detection is converted into corresponding coordinates in the mask design drawing, that is, the defect coordinates include:

[0034] Obtain the minimum enclosing rectangle of the defect contour by calculation;

[0035] Calibrate the coordinates of the rectangle and use the coordinates of the rectangle as the defect coordinates.

[0036] Calibrate the coordinates of a corner of the rectangle as the coordinates of the rectangle.

[0037] Specifically, in step S4, the defect coordinates in the defect data layer are displayed in a list, and after selecting a defect coordinate, the actual location of the defect of the current defect coordinate in the mask design drawing is displayed in the window. Figure 5 As shown in the figure, polygon represents a defect, which is composed of the defect's circumscribed rectangle. The coordinates after at represent the coordinates of the lower left corner of the defect's circumscribed rectangle, that is, the defect coordinates.

[0038] Specifically, Figure 3 , 4 As shown in the figure, whether the defect has a practical impact is determined as follows:

[0039] The impact of the defect can be determined by changing the viewport of the display window to display the details of the defect or the periphery of the defect on the mask design drawing. Specifically, the viewport of the display window can be enlarged to display more graphic information of the design drawing near the defect, or the viewport of the display window can be reduced to display the local details of the defect on the design drawing.

[0040] For example, in wafer defect detection, we are often concerned about whether there are breaks in critical circuits but not non-critical circuits. In terms of graphic form, the two types of graphics are very similar, and it is difficult to judge from a local point whether its true attribute is a critical circuit or a non-critical circuit. Its attributes can only be judged through the context of the defect location (the surrounding area, which can be called nearby graphics). In general, it is impossible to move the platform to observe the pattern near the defect to determine its attributes in an offline state.

[0041] Specifically, step S1 is as follows: selecting the DIE to DB inspection mode on the AOI inspection equipment, selecting the corresponding mark point to position the semiconductor mask, and then performing defect detection, and converting the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing based on the mark point, that is, the defect coordinates.

[0042] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for visualizing defects in semiconductor mask inspection, characterized in that: The steps of the method include: S1: Perform defect detection on the mask, and convert the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing, that is, the defect coordinates; S2: Generate a GDS file from the design database file of the mask design drawing and the obtained defect coordinates; wherein the design database file forms the database file layer of the GDS file, and the defect coordinates form the defect data layer of the GDS file; S3: Open the GDS file using an EDA tool in an offline state to simultaneously overlay and display the mask design corresponding to the database file layer and the defects corresponding to the defect data layer; S4: Through the defect coordinates in the defect data layer, check the location of the defect where the defect coordinates are located in the mask design drawing in the window to determine whether the defect has actual impact.

2. The visualization method according to claim 1, characterized in that: In step S1, the defect position obtained by defect detection is converted into corresponding coordinates in the mask design drawing, that is, the defect coordinates include: Obtain the minimum enclosing rectangle of the defect contour by calculation; Calibrate the coordinates of the rectangle and use the coordinates of the rectangle as the defect coordinates.

3. The visualization method according to claim 2, characterized in that: Calibrate the coordinates of a corner of the rectangle as the coordinates of the rectangle.

4. The visualization method according to claim 1, characterized in that: In step S4, the defect coordinates in the defect data layer are displayed in a list, and after a certain defect coordinate is selected, the actual position of the defect of the current defect coordinate in the mask design drawing is displayed in the window.

5. The visualization method according to claim 1, characterized in that: The specific criteria for determining whether a defect has a practical impact are: By changing the viewport of the display window to display the details of the defect or the periphery of the defect on the mask design, the impact of the defect can be determined.

6. The visualization display method according to claim 1, characterized in that: Step S1 is specifically as follows: selecting the DIE to DB inspection mode on the AOI inspection equipment, selecting the corresponding mark point to locate the semiconductor mask, and then performing defect detection, and converting the defect position obtained by the defect detection into the corresponding coordinates in the mask design drawing based on the mark point, that is, the defect coordinates.

Images