APPARATUS AND METHODS FOR PREDICTING WAFER-LEVEL DEFECT PRINTABILITY
First Claim
1. A method of qualifying a photolithographic reticle, the method comprising:
- using an optical reticle inspection tool, acquiring a plurality of images at different imaging configurations from each of a plurality of pattern areas of a calibration reticle;
recovering a reticle near field for each of the pattern areas of the calibration reticle based on the acquired images from each pattern area of the calibration reticle;
using the recovered reticle near field for the calibration reticle, generating a lithography model for simulating a plurality of wafer images based on the reticle near field;
using an optical reticle inspection tool, acquiring a plurality of images at different imaging configurations from each of a plurality of pattern areas of a test reticle;
recovering a reticle near field for each of the pattern areas of the test reticle based on the acquired images from each pattern area of the test reticle;
applying the generated model to the reticle near field for the test reticle to simulate a plurality of test wafer images; and
analyzing the simulated test wafer images to determine whether the test reticle will likely result in an unstable or defective wafer.
1 Assignment
0 Petitions
Accused Products
Abstract
Disclosed are methods and apparatus for qualifying a photolithographic reticle. A reticle inspection tool is used to acquire images at different imaging configurations from each of the pattern areas of a calibration reticle. A reticle near field is recovered for each of the pattern areas of the calibration reticle based on the acquired images from each pattern area of the calibration reticle. Using the recovered reticle near field for the calibration reticle, a lithography model for simulating wafer images is generated based on the reticle near field. Images are then acquired at different imaging configurations from each of the pattern areas of a test reticle. A reticle near field for the test reticle is then recovered based on the acquired images from the test reticle. The generated model is applied to the reticle near field for the test reticle to simulate a plurality of test wafer images, and the simulated test wafer images are analyzed to determine whether the test reticle will likely result in an unstable or defective wafer.
-
Citations
29 Claims
-
1. A method of qualifying a photolithographic reticle, the method comprising:
-
using an optical reticle inspection tool, acquiring a plurality of images at different imaging configurations from each of a plurality of pattern areas of a calibration reticle; recovering a reticle near field for each of the pattern areas of the calibration reticle based on the acquired images from each pattern area of the calibration reticle; using the recovered reticle near field for the calibration reticle, generating a lithography model for simulating a plurality of wafer images based on the reticle near field; using an optical reticle inspection tool, acquiring a plurality of images at different imaging configurations from each of a plurality of pattern areas of a test reticle; recovering a reticle near field for each of the pattern areas of the test reticle based on the acquired images from each pattern area of the test reticle; applying the generated model to the reticle near field for the test reticle to simulate a plurality of test wafer images; and analyzing the simulated test wafer images to determine whether the test reticle will likely result in an unstable or defective wafer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. An inspection system for qualifying a photolithographic reticle, the system comprising:
-
a light source for generating an incident beam; an illumination optics module for directing the incident beam onto a reticle; a collection optics module for directing an output beam from each pattern area of the reticle to at least one sensor; at least one sensor for detecting the output beam and generating an image or signal based on the output beam; and a controller that is configured to perform the following operations; causing the acquiring of a plurality of images at different imaging configurations from each of a plurality of pattern areas of a calibration reticle; recovering a reticle near field for each of the pattern areas of the calibration reticle based on the acquired images from each pattern area of the calibration reticle; using the recovered reticle near field for the calibration reticle, generating a lithography model for simulating a plurality of wafer images based on the reticle near field; causing the acquiring of a plurality of images at different imaging configurations from each of a plurality of pattern areas of a test reticle; recovering a reticle near field for each of the pattern areas of the test reticle based on the acquired images from each pattern area of the test reticle; applying the generated model to the reticle near field for the test reticle to simulate a plurality of test wafer images; and analyzing the simulated test wafer images to determine whether the test reticle will likely result in an unstable or defective wafer. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
-
Specification