阅读说明：本技术 晶圆密集缺陷源头检测方法及其检测系统 (Wafer dense defect source detection method and detection system thereof ) 是由 丁韵蔚 于 2021-01-26 设计创作，主要内容包括：本发明提供了一种晶圆密集缺陷源头检测方法及其检测系统,所述晶圆密集缺陷源头检测方法包括以下步骤：扫描晶圆上每个芯片的缺陷数量并形成缺陷分布图；根据每个芯片上缺陷的数量及色块定义表将所述缺陷分布图转化为色块分布图；按照拍照定义表对所述色块分布图进行区分,并对所述芯片中满足预设条件的缺陷图像自动拍照。通过设定好的拍照定义表对所述色块分布图进行区分,并对所述芯片中满足预设条件的缺陷图像进行拍照,从而快速找出密集缺陷的源头,避免二次派工影响产能,提高制品效率。(The invention provides a wafer dense defect source detection method and a detection system thereof, wherein the wafer dense defect source detection method comprises the following steps: scanning the defect number of each chip on the wafer and forming a defect distribution diagram; converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table; and distinguishing the color block distribution diagram according to a photographing definition table, and automatically photographing defect images meeting preset conditions in the chip. The color lump distribution map is distinguished through a set photographing definition table, and the defect image meeting the preset condition in the chip is photographed, so that the source of the dense defect is found out quickly, the influence of secondary dispatching on productivity is avoided, and the product efficiency is improved.)

1. A wafer dense defect source detection method is characterized by comprising the following steps:

scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and distinguishing the color block distribution diagram according to a photographing definition table, and photographing the defect image meeting the preset conditions in the chip.

2. The wafer dense defect source detection method of claim 1, wherein the step of converting the defect distribution map into a color block distribution map according to the number of defects on each chip and a color block definition table specifically comprises:

when the number of the defects on the chip is larger than a first threshold value, enabling the color block corresponding to the chip to be vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

3. The wafer dense defect source detection method as claimed in claim 2, wherein the first threshold, the second threshold, the third threshold and the fourth threshold are 5000, 2000, 1000 and 500 respectively.

4. The wafer dense defect source detection method of claim 2, wherein the color block distribution maps are distinguished according to a photographing definition table, and the step of photographing the defect image satisfying the preset condition in the chip specifically comprises:

when at least two color blocks in adjacent color blocks are vermilion, selecting a first number of defects from the chips corresponding to the vermilion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

5. The wafer dense defect source detection method of claim 4, wherein the first number, the second number and the third number are 30, 20 and 10, respectively.

6. A system for detecting a source of a dense defect in a wafer, comprising:

the image acquisition module is used for scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

the color block conversion module is used for converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and the photographing module is used for distinguishing the color block distribution diagram according to a photographing definition table and photographing the defect image meeting the preset conditions in the chip.

7. The wafer dense defect source detection system of claim 6, wherein the color block conversion module is specifically configured to:

when the number of the defects on the chip is larger than a first threshold value, enabling the color block corresponding to the chip to be vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

8. The wafer dense defect source detection system of claim 7, wherein the first threshold, the second threshold, the third threshold and the fourth threshold are 5000, 2000, 1000 and 500, respectively.

9. The wafer dense defect source detection system of claim 7, wherein the photographing module is specifically configured to:

when at least two color blocks in adjacent color blocks are vermillion, selecting a first number of defects from the chips corresponding to the vermillion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

10. The wafer dense defect source detection system of claim 9, wherein the first number, the second number and the third number are 30, 20 and 10, respectively.

Technical Field

The invention belongs to the technical field of semiconductor defect detection, and particularly relates to a wafer dense defect source detection method and a wafer dense defect source detection system.

Background

In the production process of large scale integrated circuit wafers, with the diversification of products, each product needs to have a site to monitor the defect condition so as to prevent a large number of wafers from suffering from the same defect due to the absence of scanning sites, thereby reducing the yield of the products. As the geometric dimension of the wafer is reduced, the yield loss rate caused by the defects is increased, and the size of the defects affecting the yield is reduced, so the precision requirements of the optical scanning program and the electron beam scanning program are increased.

The commonly used process of detecting defects by using patterns is to extract abnormal points (sampling) by using an optical scanning machine, wherein the commonly used optical scanning means comprises bright field scanning and dark field scanning, and then the extracted defect appearance is observed by using an electron beam scanning machine. For some aggregate defects, the number of defects transmitted by the optical scanner is often high, while the defects observed by the electronic scanner are defects in which only a fixed number of optical scan results are extracted. Defects (defects) at the source of defect generation are often not extracted, so that only some accompanying defects are found during review (review), and the source of the defects is not found. For the source defect, the defect source needs to be manually found through secondary dispatching. The productivity of the machine table has certain influence, and for serious defect problems, the timeliness cannot be met by repeated observation, and the efficiency of more products can be influenced.

Disclosure of Invention

The invention aims to provide a wafer dense defect source detection method and a wafer dense defect source detection system, which can quickly find out the source of the dense defect, avoid the influence of secondary dispatching on productivity and improve the product efficiency.

In order to achieve the above object, the present invention provides a method for detecting a source of a dense defect of a wafer, comprising the following steps:

scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and distinguishing the color block distribution diagram according to a photographing definition table, and photographing the defect image meeting the preset conditions in the chip.

Optionally, the step of converting the defect distribution map into a color block distribution map according to the number of defects on each chip and the color block definition table specifically includes:

when the number of the defects on the chip is larger than a first threshold value, enabling the color block corresponding to the chip to be vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

Optionally, the first threshold, the second threshold, the third threshold, and the fourth threshold are 5000, 2000, 1000, and 500, respectively.

Optionally, the step of distinguishing the color block distribution map according to a photographing definition table, and photographing the defect image meeting the preset condition in the chip specifically includes:

when at least two color blocks in adjacent color blocks are vermilion, selecting a first number of defects from the chips corresponding to the vermilion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

Optionally, the first number, the second number and the third number are respectively 30, 20 and 10.

Based on this, the invention also provides a wafer dense defect source detection system, which comprises:

the image acquisition module is used for scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

the color block conversion module is used for converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and the photographing module is used for distinguishing the color block distribution diagram according to a photographing definition table and photographing the defect image meeting the preset conditions in the chip.

Optionally, the color block conversion module is specifically configured to:

when the number of the defects on the chip is larger than a first threshold value, enabling the color block corresponding to the chip to be vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

Optionally, the first threshold, the second threshold, the third threshold, and the fourth threshold are 5000, 2000, 1000, and 500, respectively.

Optionally, the photographing module is specifically configured to:

when at least two color blocks in adjacent color blocks are vermillion, selecting a first number of defects from the chips corresponding to the vermillion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

Optionally, the first number, the second number and the third number are respectively 30, 20 and 10.

In the wafer dense defect source detection method and the detection system thereof provided by the invention, the defect distribution map is formed by scanning the defect number of each chip on the wafer, then the defect distribution map is converted into the color block distribution map according to the defect number of each chip and the color block definition table, then the color block distribution map is distinguished according to the photographing definition table, and the defect image meeting the preset conditions in the chip is photographed. The color block distribution diagram is distinguished according to a set photographing definition table, so that the source of the dense defects can be found out quickly, the influence of secondary dispatching on productivity is avoided, and the product efficiency is improved.

Drawings

It will be appreciated by those skilled in the art that the drawings are provided for a better understanding of the invention and do not constitute any limitation to the scope of the invention. Wherein:

FIG. 1 is a block diagram of a method for detecting a dense defect source in a wafer according to an embodiment of the present invention;

FIG. 2 is a defect distribution diagram of a wafer according to an embodiment of the present invention.

Detailed Description

To further clarify the objects, advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. It is to be noted that the drawings are in greatly simplified form and are not to scale, but are merely intended to facilitate and clarify the explanation of the embodiments of the present invention. Further, the structures illustrated in the drawings are often part of actual structures. In particular, the drawings may have different emphasis points and may sometimes be scaled differently. It should be further understood that the terms "first," "second," "third," and the like in the description are used for distinguishing between various components, elements, steps, and the like, and are not intended to imply a logical or sequential relationship between various components, elements, steps, or the like, unless otherwise indicated or indicated.

Referring to fig. 1, the present embodiment provides a method for detecting a source of a wafer dense defect, which includes the following steps:

s1, scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

s2, converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and S3, distinguishing the color block distribution diagram according to a photographing definition table, and photographing the defect image meeting the preset conditions in the chip.

Specifically, step S1 is performed to scan the number of defects on each chip of the wafer and form a defect map. It should be understood that there are usually many accompanying defects around the source of the dense defect, and the source is used as the center to expand to the periphery, so that the defect distribution map can be formed to facilitate finding out the chips with more defects, so as to determine whether the chips are the source of the defect or not in the following further process. As shown in fig. 2, fig. 2 is a defect distribution diagram of a wafer according to an embodiment of the present invention, wherein the number indicates the number of defects on the chip, and the larger the number, the larger the number of defects. It should be understood that the values in fig. 2 are not true detected values, but are for exemplary illustration only.

Then, step S2 is executed to convert the defect distribution map into a color block distribution map according to the number of defects on each chip and a color block definition table, where step S2 specifically includes:

when the number of the defects on the chip is larger than a first threshold value, enabling the color block corresponding to the chip to be vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

In this embodiment, the first threshold, the second threshold, the third threshold, and the fourth threshold are 5000 (ea), 2000 (ea), 1000 (ea), and 500 (ea), respectively.

TABLE 1

With reference to table 1, table 1 is a color patch definition table provided in the embodiment of the present invention, and thus it can be seen that the number of defects on a chip corresponding to a vermilion color patch is the largest, and the number of defects on a chip corresponding to a green color patch is the smallest. Of course, the present application does not limit the specific values of the first threshold, the second threshold, the third threshold and the fourth threshold.

And finally, executing a step S3, distinguishing the color block distribution diagram according to a photographing definition table, and photographing a defect image meeting preset conditions in the chip, wherein the step S2 specifically comprises the following steps:

when at least two color blocks in adjacent color blocks are vermillion, selecting a first number of defects from the chips corresponding to the vermillion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

It should be understood that, for dense defects, the size of the defect has a close relationship with whether the defect is a source of the defect, and the source of the defect can be found more effectively by further judging vermilion, bright red and yellow color blocks representing a large number of defects in real time. And subsequently, the defects after photographing can be analyzed and judged, and the sources of the defects and the reasons for the formation of the defects are determined.

In this embodiment, the first number, the second number, and the third number are 30, 20, and 10, respectively. Of course, the present application does not limit the specific values of the first quantity, the second quantity and the third quantity.

TABLE 2

With reference to table 2 and table 2 as a photographing definition table provided in the embodiment of the present invention, it can be seen that, with adjacent color blocks as determination conditions, only when the number of vermilion color blocks is greater than two color blocks, the number of bright red color blocks is greater than four color blocks, or the number of yellow color blocks is greater than eight color blocks, a defect image meeting preset conditions in a chip corresponding to the color block is photographed, so as to further determine a source of the dense defect. The color of the adjacent color blocks is used for judgment, so that chips which possibly have defect sources are rapidly screened out, the chips are photographed according to the size of the defects, and the detection efficiency can be greatly improved.

Based on this, this embodiment also provides a dense defect source detecting system of wafer, includes:

the image acquisition module is used for scanning the defect number of each chip on the wafer and forming a defect distribution diagram;

the color block conversion module is used for converting the defect distribution map into a color block distribution map according to the number of the defects on each chip and a color block definition table;

and the photographing module is used for distinguishing the color block distribution diagram according to a photographing definition table and photographing the defect image meeting the preset conditions in the chip.

In this embodiment, a Scanning Electron Microscope (SEM) may be used as a defect observation machine for defect detection, a color block conversion module and a photographing module are embedded in the SEM in a programming manner, defect distribution is analyzed and determined in real time, the dense defect category is defined by the color block conversion module, and finally, a defect source is searched for a defect image satisfying a preset condition in the chip by the photographing module.

In this embodiment, when the number of defects on the chip is greater than a first threshold, the color block corresponding to the chip is vermilion in color;

when the number of the defects on the chip is larger than a second threshold value and smaller than the first threshold value, enabling the color block color corresponding to the chip to be bright red;

when the number of the defects on the chip is larger than a third threshold value and smaller than the second threshold value, enabling the color block color corresponding to the chip to be yellow;

when the number of the defects on the chip is larger than a fourth threshold value and smaller than a third threshold value, enabling the color block color corresponding to the chip to be orange;

and when the number of the defects on the chip is smaller than the fourth threshold value, enabling the color block color corresponding to the chip to be green.

Wherein the first threshold, the second threshold, the third threshold and the fourth threshold are 5000, 2000, 1000 and 500 respectively.

In this embodiment, the photographing module is specifically configured to:

when at least two color blocks in adjacent color blocks are vermillion, selecting a first number of defects from the chips corresponding to the vermillion color blocks from large to small for photographing;

when at least four color blocks in adjacent color blocks are bright red, selecting a second number of defects from the chips corresponding to the bright red color blocks from large to small for photographing;

and when at least eight color blocks in the adjacent color blocks are yellow, selecting a third number of defects from large to small from the chip corresponding to the yellow color blocks for photographing.

Wherein the first number, the second number, and the third number are 30, 20, and 10, respectively.

In summary, the invention provides a method for detecting a source of a dense defect of a wafer, which is characterized in that the color block distribution diagram is distinguished according to a set photographing definition table, and a defect image meeting a preset condition in the chip is photographed, so that the source of the dense defect is quickly found out, the influence of secondary dispatching on productivity is avoided, and the product efficiency is improved. Based on this, this embodiment further provides a system for implementing a wafer dense defect source detection method, which may use a Scanning Electron Microscope (SEM) as a defect observation machine for defect detection, then embed a color block conversion module and a photographing module in the SEM in a programming manner, analyze and judge defect distribution in real time, define the dense defect category through the color block conversion module, and finally search for a defect source from a defect image satisfying a preset condition in the chip through the photographing module.

It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. It will be apparent to those skilled in the art from this disclosure that many changes and modifications can be made, or equivalents modified, in the embodiments of the invention without departing from the scope of the invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention are still within the protection scope of the technical solution of the present invention, unless the content of the technical solution of the present invention is departed from.