JP2004363223A - Equipment, system, method, and program for defect inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively form a recipe for extracting defect of semiconductor. <P>SOLUTION: On the basis of comparison result of image data observed by an SEM 3 with a reference pattern memorized in a reference pattern memory 6, correction of defect extracted by a defect detecting apparatus 1 is judged. Selection of recipes A-N is performed based on matching ratio of the correction of the defect extracted by the defect detecting apparatus 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a defect inspection apparatus, a defect inspection system, a defect inspection method, and a defect inspection program, and is particularly suitable for application to a method of creating a recipe used for defect inspection.
[0002]
[Prior art]
In a conventional defect inspection apparatus, for example, as disclosed in Patent Literature 1, by providing a SEM (scanning electron microscope) with a dimension measurement function, a pattern defect inspection function, and a review function, the efficiency of defect inspection is improved. A method has been implemented.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2000-252332
[Problems to be solved by the invention]
However, in the conventional defect inspection apparatus, it is necessary to manually adjust the recipe for extracting the defects while reviewing the extracted defects, which has a problem that the efficiency of defect extraction is low.
Accordingly, an object of the present invention is to provide a defect inspection apparatus, a defect inspection system, a defect inspection method, and a defect inspection program that can efficiently create a recipe for extracting a defect.
[0005]
[Means for Solving the Problems]
According to one embodiment of the present invention, there is provided a defect inspection apparatus configured to acquire defect data detected based on a predetermined recipe. Image data acquisition means for acquiring image data by a scanning electron microscope; defect determination means for determining whether a defect specified by the defect data is correct based on a comparison result between the image data and a reference pattern; A matching ratio calculating unit that calculates a matching ratio of the defect based on the correctness of the defect, and a recipe selecting unit that selects the recipe based on the matching ratio of the defect. Features.
[0006]
This makes it possible to reflect the result of determining whether the defect is correct or incorrect in the selection of the recipe. For this reason, it is possible to generate a recipe for correctly extracting a defect without troublesome labor, and to improve the efficiency of the defect inspection.
Further, according to the defect inspection apparatus of one aspect of the present invention, when the matching ratio is equal to or less than a specified value, the defect data acquiring unit acquires defect data detected by a different recipe.
[0007]
Thus, when the frequency of erroneously extracting defects is high, the recipe can be changed so that the frequency of correctly extracting defects increases. For this reason, it is possible to optimize the recipe without labor and to improve the accuracy of the defect inspection while improving the efficiency of the defect inspection.
Further, according to the defect inspection apparatus according to an aspect of the present invention, the defect determination unit includes a defect classification unit that classifies the defect by category, and the matching ratio calculation unit includes: A rate is calculated, and the recipe selection means selects a recipe for each of the categories.
[0008]
This makes it possible to select the optimal recipe for each category, improve the accuracy of recipe creation, and efficiently create recipes that can extract only important defects It becomes.
Further, according to the defect inspection system according to one aspect of the present invention, a defect detection device provided with a plurality of recipes, a defect data acquisition unit configured to acquire defect data detected by the defect detection device, Image data acquisition means for acquiring image data by a scanning electron microscope based on data; and defect determination for judging correctness of a defect specified by the defect data based on a comparison result between the image data and a reference pattern. Means, a matching rate calculating means for calculating a correct / false matching rate of the defect based on the determination result of the correctness of the defect, and selection of a recipe in the defect detecting apparatus based on the correct / false matching rate of the defect. And a recipe selecting means for performing the following.
[0009]
This makes it possible to reflect the result of determining whether the defect is correct or incorrect in the selection of the recipe. For this reason, it is possible to select an optimal recipe for correctly extracting a defect from a plurality of recipes without troublesome labor, and to improve the efficiency of defect inspection.
According to the defect inspection method of one aspect of the present invention, the step of acquiring defect data detected based on a predetermined recipe and the step of acquiring image data by a scanning electron microscope based on the defect data Determining whether the defect specified by the defect data is correct based on a result of the comparison between the image data and the reference pattern; and performing matching of the defect based on the result of determining whether the defect is correct. A step of calculating a ratio, and a step of selecting the recipe based on a matching ratio of correctness of the defect.
[0010]
As a result, it is possible to reflect the determination result of the correctness of the defect on the selection of the recipe without troublesome operation, and it is possible to efficiently generate the recipe for correctly extracting the defect.
Further, according to the defect inspection method of one aspect of the present invention, a step of detecting a defect of the semiconductor wafer based on a predetermined recipe, and a step of scanning the image data of the semiconductor wafer based on the defect detection result with a scanning electronic device Acquiring with a microscope, determining the correctness of a defect specified by the defect data based on a comparison result between the image data and a reference pattern, and determining whether the defect is correct or incorrect based on the determination result of the defect. The method is characterized by comprising a step of calculating a correct / error matching rate of the defect, and a step of calibrating the recipe based on the correct / false matching rate of the defect.
[0011]
As a result, it is possible to reflect the determination result of the correctness of the defect of the semiconductor wafer in the generation of the recipe. For this reason, it is possible to calibrate the recipe so that the defect is correctly extracted without troublesome labor, and it is possible to efficiently perform the defect inspection of the semiconductor wafer.
Further, according to the defect inspection program according to one aspect of the present invention, a step of acquiring defect data detected based on a predetermined recipe, and, based on the defect detection result, the semiconductor wafer is scanned by a scanning electron microscope. Determining the correctness of the defect specified by the defect data based on a comparison result between the image pattern and the reference pattern observed by the scanning electron microscope. The computer is configured to execute a step of calculating a correct / incorrect matching rate of the defect based on the determination result and a step of selecting the recipe based on the correct / incorrect rate of the defect.
[0012]
This makes it possible for the computer to execute the defect inspection program so that the result of determining whether or not a defect is correct can be reflected in the selection of a recipe. Can be generated.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a defect inspection apparatus and a defect inspection method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a defect inspection system according to one embodiment of the present invention.
[0014]
In FIG. 1, a recipe storage unit 2 is provided in a defect detection device 1, and a plurality of recipes A to N for extracting defects on a semiconductor wafer are stored in the recipe storage unit 2. Here, the conditions for extracting defects on the semiconductor wafer are described in the recipes A to N, and the conditions described in the recipes A to N include, for example, a pixel size, a focus, and a defect. Thresholds and the like can be mentioned.
[0015]
Then, the defect detection device 1 extracts defects on the semiconductor wafer by inspecting the semiconductor wafer based on the recipes A to N stored in the recipe storage unit 2. In addition, as the defect detection device 1, for example, an optical type or a laser type can be used. In the optical type, the position of a defect on a semiconductor wafer is specified based on the observation result on the semiconductor wafer by an optical microscope. be able to. Further, in the laser method, the position of a defect on a semiconductor wafer can be specified based on the determination result of scattered light when laser scanning is performed on the semiconductor wafer.
[0016]
On the other hand, the SEM 3 is provided with a defect data acquisition unit 4, a defect determination unit 5, a reference pattern storage unit 6, a matching evaluation unit 7, and a recipe selection unit 8, and the SEM 3 communicates with the defect detection device 1 via a communication line 9. It is connected.
Here, the defect data acquisition unit 4 acquires the defect data detected based on the recipes A to N from the defect detection device 1. The defect data can include information indicating a defect position on the semiconductor wafer. The defect determination unit 5 determines the correctness of a defect extracted by the defect detection device 1 based on a comparison result between the image data observed by the SEM 3 and the reference pattern stored in the reference pattern storage unit 6. . The reference pattern storage unit 6 stores a defect pattern corresponding to a true defect. The matching evaluation unit 7 calculates a true / false matching rate of the defect extracted by the defect detection device 1 based on the defect determination result of the defect determined by the defect determination unit 5. The recipe selection unit 8 selects recipes A to N based on the correct / false matching rate of the defect calculated by the matching evaluation unit 7.
[0017]
The defect determination unit 5 can have an automatic defect classification (ADC) function for classifying defects by category. Here, examples of the defect category include a pattern defect, a foreign substance, discoloration, and scratch.
FIG. 2 is a flowchart showing the operation of the defect inspection apparatus of FIG.
[0018]
In FIG. 2, the defect detection device 1 inspects a semiconductor wafer based on recipes A to N stored in a recipe storage unit 2 and sends defect data specifying a defect position on the semiconductor wafer to the SEM 3. Then, when the position information of the defect on the semiconductor wafer is sent to the SEM 3, the defect data acquisition unit 4 acquires the defect data detected based on the recipes A to N (Step S1).
[0019]
Next, when the defect data acquisition unit 4 acquires the defect data, the SEM 3 observes a region on the semiconductor wafer specified by the defect data (Step S2). Then, the defect determination unit 5 determines whether the defect extracted by the defect detection device 1 is correct by comparing the image pattern observed by the SEM 3 with the reference pattern stored in the reference pattern storage unit 6. (Step S3). Here, by using the ADC function, the defect determination unit 5 can determine whether the defect extracted by the defect detection device 1 is correct or not for each category.
[0020]
Then, the matching evaluation unit 7 calculates a true / false matching rate of the defect extracted by the defect detection device 1, based on the result of the true / false determination of the defect determined by the defect determining unit 5 (step S4). Note that the matching evaluation unit 7 may calculate the correct / false matching rate of the defect extracted by the defect detection device 1 for each category.
Then, when the correct / false matching rate of the defect extracted by the defect detection device 1 exceeds the specified value, the recipe selection unit 8 selects the current recipes A to N as the optimal recipes (step S6). The matching ratio can be set, for example, within a range of 85% to 98%.
[0021]
On the other hand, when the correct / false matching rate of the defect extracted by the defect detection device 1 is equal to or less than a specified value, the matching evaluation unit 7 performs the inspection of the semiconductor wafer on the defect detection device 1 based on the recipes A to N different from the current time. The defect data detected by the different recipes A to N is obtained by the defect data obtaining unit 4 (step S7). The matching evaluation unit 7 causes the recipe selection unit 8 to select the optimal recipes A to N by repeating the above processing until the correct / false matching rate of the defect extracted by the defect detection device 1 exceeds a specified value. .
[0022]
This makes it possible to generate the recipes A to N for correctly extracting the defects without troublesome operation, and to improve the efficiency of the defect inspection of the semiconductor wafer.
Note that the recipe selection unit 8 may select the optimum recipes A to N for each category. This makes it possible to improve the accuracy of creating the recipes A to N and to remove only important defects. The recipes A to N that can be extracted can be efficiently created.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a defect inspection system according to one embodiment.
FIG. 2 is a flowchart showing the operation of the defect inspection apparatus of FIG.
[Explanation of symbols]
1 defect detection device, 2 recipe storage unit, 3 scanning electron microscope, 4 defect data acquisition unit, 5 defect determination unit, 6 reference pattern storage unit, 7 matching evaluation unit, 8 recipe selection unit, 9 communication line

Claims (7)

Defect data acquisition means for acquiring defect data detected based on a predetermined recipe,
Image data acquisition means for acquiring image data by a scanning electron microscope based on the defect data,
A defect determination unit configured to determine whether a defect specified by the defect data is correct based on a comparison result between the image data and a reference pattern;
A matching rate calculation unit that calculates a matching rate of correctness of the defect based on the determination result of correctness of the defect;
A defect selection device for selecting the recipe based on a matching rate of the defect. 2. The defect inspection apparatus according to claim 1, wherein when the matching ratio is equal to or less than a specified value, the defect data obtaining unit obtains defect data detected by a different recipe. The defect determination unit includes a defect classification unit that classifies defects by category,
The matching rate calculating means calculates a correct / false matching rate of the defect for each category,
The defect inspection apparatus according to claim 1, wherein the recipe selection unit selects a recipe for each of the categories. A defect detection device provided with a plurality of recipes,
Defect data acquisition means for acquiring defect data detected by the defect detection device predetermined;
Image data acquisition means for acquiring image data by a scanning electron microscope based on the defect data,
A defect determination unit configured to determine whether a defect specified by the defect data is correct based on a comparison result between the image data and a reference pattern;
A matching rate calculation unit that calculates a matching rate of correctness of the defect based on the determination result of correctness of the defect;
A defect inspection system, comprising: a recipe selection unit that selects a recipe in the defect detection device based on a matching rate of the defect. Obtaining defect data detected based on a predetermined recipe;
Based on the defect data, obtaining image data by a scanning electron microscope,
Determining whether the defect specified by the defect data is correct or not, based on a comparison result between the image data and a reference pattern;
A step of calculating a matching rate of correctness of the defect based on the determination result of correctness of the defect;
A step of selecting the recipe based on a matching rate of correctness of the defect. Detecting a defect in the semiconductor wafer based on a predetermined recipe;
Observing the semiconductor wafer with a scanning electron microscope based on the defect detection result,
Based on a comparison result between the image pattern and the reference pattern observed by the scanning electron microscope, determining the correctness of the defect specified by the defect data,
A step of calculating a matching rate of correctness of the defect based on the determination result of correctness of the defect;
Performing a calibration of the recipe based on a matching ratio of correctness of the defect. Obtaining defect data detected based on a predetermined recipe;
Based on the defect data, obtaining image data by a scanning electron microscope,
Determining whether the defect specified by the defect data is correct or not, based on a comparison result between the image data and a reference pattern;
A step of calculating a matching rate of correctness of the defect based on the determination result of correctness of the defect;
A step of selecting the recipe based on the correct / incorrect matching ratio of the defect.

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