Determining one or more characteristics of a pattern of interest on a specimen

Patent metadata

Field	Value
Publication number	US-10359371-B2
Application number	US-201615243809-A
Country	US
Kind code	B2
Filing date	Aug 22, 2016
Priority date	Aug 24, 2015
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

Methods and systems for determining characteristic(s) of patterns of interest (POIs) are provided. One system is configured to acquire output of an inspection system generated at the POI instances without detecting defects at the POI instances. The output is then used to generate a selection of the POI instances. The system then acquires output from an output acquisition subsystem for the selected POI instances. The system also determines characteristic(s) of the POI using the output acquired from the output acquisition subsystem.

First claim

What is claimed is:

1. A system configured to determine one or more characteristics of a pattern of interest on a specimen, comprising:
an output acquisition subsystem comprising at least an energy source and a detector, wherein the output acquisition subsystem is configured to direct energy generated by the energy source to a specimen while the detector detects energy from the specimen and generates output responsive to the detected energy, and wherein the specimen is a wafer; and
a computer subsystem comprising one or more processors configured to execute instructions from a memory medium, wherein the computer subsystem is configured for:
acquiring output of an inspection system generated by the inspection system for at least a majority of instances of a pattern of interest formed on the specimen and stored in a computer-readable storage medium, wherein the inspection system is an optical or electron beam inspection system, wherein the output of the inspection system comprises images of the pattern of interest formed on the specimen generated by one or more detectors of the optical or electron beam inspection system while the specimen is being scanned by the inspection system, wherein the one or more detectors of the optical or electron beam inspection system generate the output of the inspection system at a resolution that is lower than a resolution with which the detector of the output acquisition subsystem generates the output of the output acquisition subsystem, and wherein the inspection system stores the output acquired at the at least the majority of instances regardless of characteristics of the output of the inspection system;
selecting one or more of the at least the majority of instances at which the output is generated by the output acquisition subsystem, wherein said selecting is performed based on the characteristics of the output of the inspection system;
acquiring the output generated by the output acquisition subsystem for the selected one or more of the at least the majority of instances, wherein the resolution of the output acquisition subsystem with which the output of the output acquisition subsystem is generated by the detector of the output acquisition subsystem at the selected one or more of the at least the majority of instances is higher than the resolution at which the one or more detectors of the inspection system generate the output of the inspection system; and
determining one or more characteristics of the pattern of interest based on the output of the output acquisition subsystem at the selected one or more of the at least the majority of instances.

2. The system of claim 1 , wherein the one or more characteristics of the pattern of interest determined based on the output of the output acquisition subsystem are not detectable in any output generated by the inspection system.

3. The system of claim 1 , wherein the inspection system identities the locations of the at least the majority of the instances of the pattern of interest on the specimen without detecting defects on the specimen, and wherein selecting the one or more of the at least the majority of instances is not performed based on defects detected at the instances of the pattern of interest.

4. The system of claim 1 , wherein the instances of the pattern of interest on the specimen are located by the inspection system with sub-pixel accuracy.

5. The system of claim 1 , wherein the output for the selected one or more of the at least the majority of instances is generated by the output acquisition subsystem by locating the selected one or more of the at least the majority of instances with sub-pixel accuracy.

6. The system of claim 1 , wherein said determining the one or more characteristics is performed based on the output of the output acquisition subsystem at the selected one or more of the at least the majority of instances in combination with the output of the inspection system generated for at least one of the instances of the pattern of interest.

7. The system of claim 1 , wherein said determining the one or more characteristics comprises determining one or more initial values for the one or more characteristics of the pattern of interest based on the output of the output acquisition subsystem at the selected one or more of the at least the majority of instances in combination with a first portion of the output of the inspection system generated for at least one of the instances of the pattern of interest and, based on the one or more initial values, selecting a second portion of the output of the inspection system generated for at least one of the instances of the pattern of interest stored in the computer-readable storage medium and determining the one or more characteristics of the pattern of interest based on the output of the output acquisition subsystem at the selected one or more of the at least the majority of instances in combination with the second portion of the output of the inspection system generated for the at least one of the instances of the pattern of interest.

8. The system of claim 1 , wherein the computer subsystem is further configured for determining a variation in the one or more characteristics of the pattern of interest and determining a source of the variation based on the variation.

9. The system of claim 1 , wherein the determined one or more characteristics of the pattern of interest correspond to only patterning deviations in the pattern of interest.

10. The system of claim 1 , wherein the characteristics of the output of the inspection system comprise characteristics of raw image data generated by the inspection system for the at least the majority of the instances of the pattern of interest.

11. The system of claim 1 , wherein the computer subsystem is further configured for determining one or more relationships between one or more of the characteristics of the output of the inspection system and the one or more characteristics of the pattern of interest and determining one or more parameters used for the selecting based on the one or more relationships.

12. The system of claim 11 , wherein determining the one or more relationships is performed using machine learning.

13. The system of claim 11 , wherein the computer subsystem is further configured for performing data reduction on the output of the inspection system for the at least the majority of instances of the pattern of interest used for determining the one or more relationships by identifying a first portion of the at least the majority of instances, wherein the first portion includes fewer than all of the at least the majority of the instances, and wherein determining the one or more relationships is performed based on only the one or more characteristics of the output generated by the inspection system for the first portion of the at least the majority of instances.

14. The system of claim 11 , wherein the computer subsystem is further configured for performing data reduction on the output of the inspection system for the at least the majority of the instances of the pattern of interest used for determining the one or more relationships by identifying a first, portion of the output of the inspection system for the at least the majority of instances that is optically relevant and eliminating a second portion of the output of the inspection system for the at least the majority of instances that is not optically relevant, and wherein the first portion of the output of the inspection system comprises the output of the inspection system corresponding to actual defects in the instances of the pattern of interest.

15. The system of claim 11 , wherein t

Assignees

• Kla Tencor Corp

Inventors

• Duffy Brian
• Kulkarni Ashok
• Lennek Michael
• Park Allen

Classifications

• H10P74/203 Primary

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/23 Primary

  characterised by multiple measurements, corrections, marking or sorting processes · CPC title

• G05B19/41875

  characterised by quality surveillance of production · CPC title

• G06T2207/30148

  Semiconductor; IC; Wafer · CPC title

• G06T7/001

  using an image reference approach · CPC title