High sensitivity repeater defect detection

Patent metadata

Field	Value
Publication number	US-10395358-B2
Application number	US-201715804980-A
Country	US
Kind code	B2
Filing date	Nov 6, 2017
Priority date	Nov 10, 2016
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

Systems and methods for detecting defects on a reticle are provided. One system includes computer subsystem(s) that include one or more image processing components that acquire images generated by an inspection subsystem for a wafer, a main user interface component that provides information generated for the wafer and the reticle to a user and receives instructions from the user, and an interface component that provides an interface between the one or more image processing components and the main user interface. Unlike currently used systems, the one or more image processing components are configured for performing repeater defect detection by applying a repeater defect detection algorithm to the images acquired by the one or more image processing components, and the repeater defect detection algorithm is configured to detect defects on the wafer using a hot threshold and to identify the defects that are repeater defects.

First claim

What is claimed is:

1. A system configured to detect defects on a reticle, comprising:
an inspection subsystem configured to scan a wafer to thereby generate images for the wafer, wherein a reticle is used to print features on the wafer in a lithography process; and
one or more computer subsystems comprising:
one or more image processing components configured for acquiring the images generated by the inspection subsystem for the wafer;
a main user interface component configured for providing information generated for the wafer and the reticle to a user and for receiving instructions from the user; and
an interface component configured for providing an interface between t one or more image processing components and the main user interface component and for controlling one or more hardware elements of the inspection subsystem;
wherein the one or more image processing components are further configured for performing repeater defect detection by applying a repeater defect detection algorithm to the images acquired by the one or more image processing components, and wherein the repeater defect detection algorithm is configured to detect defects on the wafer using a hot threshold and to identify the defects that are repeater defects;
wherein the one or more image processing components are further configured for sending inspection results comprising information for only the repeater defects to the interface component; and
wherein the one or more computer subsystems are configured for identifying defects on the reticle based on the repeater defects detected on the wafer.

2. The system of claim 1 , wherein the repeater defect detection algorithm is further configured to identify the defects that are the repeater defects by comparing the within die defect coordinates for different of the defects to each other.

3. The system of claim 1 , wherein the one or more image processing components are further configured for storing information for all of the detected defects.

4. The system of claim 1 , wherein performing the repeater defect detection is performed for only a single swath on the wafer.

5. The system of claim 1 , wherein the one or more image processing components are further configured as a virtual inspector, and wherein the one or more computer subsystems are further configured for disconnecting the virtual inspector from the inspection subsystem after the images are acquired from the inspection subsystem and before the repeater defect detection is performed.

6. The system of claim 1 , wherein the one or more image processing components are further configured for performing single swath-multiple die row defect detection by applying a defect detection algorithm to the images generated by the inspection subsystem for the same single swath in multiple die rows on the wafer and for sending results of the single swath-multiple die row defect detection to the interface component, and wherein the interface component or the main user interface component performs repeater defect detection on the results of the single swath-multiple die defect detection.

7. The system of claim I, wherein the one or more image processing components comprise a shared non-transitory computer-readable storage medium accessible for multiple processes performed by the one or more image processing components, and wherein the repeater defect detection algorithm is further configured to detect the defects on the entire inspected area of the wafer, to store all of the detected defects in the shared non-transitory computer-readable storage medium, and to identify the defects that are the repeater defects using all of the stored detected defects for the entire inspected area of the wafer.

8. The system of claim 1 , wherein the one or more image processing components are further configured for performing single swath-multiple die row defect detection by applying a defect detection algorithm to the images generated by the inspection subsystem for the same single swath in multiple die rows on the wafer and storing results of the single swath-multiple die row defect detection in a shared non-transitory computer-readable storage medium in the one or more image processing components accessible for multiple processes performed by the one or more image processing components, and wherein the repeater defect detection algorithm is further configured to detect the defects in the entire inspected area of the same single swath in the multiple die rows, to store all of the detected defects in the shared non-transitory computer-readable storage medium, and to identify the defects that are the repeater defects using all of the stored detected defects for the entire inspected area of the same single swath in the multiple die rows.

9. The system of claim 1 , wherein the one or more image processing components comprise a shared non-transitory computer-readable storage medium accessible for multiple processes performed by the one or more image processing components, wherein the one or more computer subsystems further comprise a virtual inspector, wherein the one or more image processing components are further configured for storing only a first portion of results produced by the repeater defect detection algorithm in the shared non-transitory computer-readable storage medium and only a second portion of the results produced by the repeater defect detection algorithm in the virtual inspector, wherein the first portion comprises only defect coordinates for the defects detected on the wafer, wherein the second portion comprises only defect attributes and patch images for the detected defects on the wafer, wherein the repeater defect detection algorithm is further configured to identify the repeater defects using only the first portion of the results, and wherein the one or more image processing components are further configured for retrieving the defect attributes and patch images for the repeater defects from the virtual inspector and generating the inspection results by combining information generated by identifying the repeater defects with the retrieved defect attributes and patch images.

10. The system of claim 1 , wherein the one or more image processing components comprise a shared non-transitory computer-readable storage medium accessible for multiple processes performed by the one or more image processing components, wherein the one or more image processing components are further configured for storing only a first portion of results produced by the repeater defect detection algorithm in the shared non-transitory computer-readable storage medium, wherein the first portion comprises only defect coordinates for the defects detected on the wafer, Wherein the repeater defect detection algorithm is further configured to identify the repeater defects using only the first portion of the results, wherein the interface component is further configured for controlling the one or more hardware elements of the inspection subsystem to thereby scan only locations on the wafer of the identified repeater defects, and wherein the one or more image processing components are further configured for combining images generated in the scan of only the locations on the wafer of the identified repeater defects with the first portion of the results to thereby generate the inspection results that are sent to the interface component.

11. The system of claim 1 , wherein the repeater defect detection algorithm is further configured to identify the defects that appear at the same location in two or more printed instances of the reticle on the wafer as the repeater defects.

12. The system of claim 1 , wherein the one or more computer subsystems are further configured for identify

Assignees

• Kla Tencor Corp

Inventors

• Brauer Bjorn
• Shifrin Eugene
• Mathew Ashok
• Bhaskar Chetana
• Gao Lisheng
• Bhattacharyya Santosh
• Lee Hucheng
• Murray Benjamin

Classifications

• G06T2207/20076

  Probabilistic image processing · CPC title

• G06T7/0004

  Industrial image inspection · CPC title

• G06T2207/20224

  Image subtraction · CPC title

• G06T2207/10152

  Varying illumination · CPC title

• G01N2021/95676

  Masks, reticles, shadow masks · CPC title