Granted Patent B2

US 12,265,212 · App. 18/070,389 · Granted Apr 1, 2025

Inventors: James Jianguo Xu (San Jose, CA); Ken Kinsun Lee (Los Altos Hills, CA); Rusmin Kudinar (Fremont, CA); Ronny Soetarman (Fremont, CA); Hung Phi Nguyen (Santa Clara, CA); Zhen Hou (Fremont, CA)

Assignee: KLA-Tencor Corporation

G02B21/06G02B21/0092G02B21/367

Abstract

Claims (17)

1. A method of 3D imaging or measuring a sample, the method comprising:

acquiring a 3D image of a flat reference surface devoid of any features by varying a relative distance between the reference surface and an objective lens at a first plurality of predetermined steps;

at first predetermined steps:

at each of a first set of predetermined steps of the first plurality of predetermined steps:

projecting an image of a patterned article onto a focal plane of the objective lens;

capturing a first image with a pattern associated with the patterned article and the reference surface, and storing the first image in a first image array;

at each of a second set of predetermined steps of the first plurality of predetermined steps:

capturing a second image of the reference surface without the pattern associated with the patterned article, and storing the second image in a second image array;

generating a 3D image of the reference surface by analyzing the first and second images;

acquiring a 3D image of the sample by varying a relative distance between the sample and the objective lens at a second plurality of predetermined steps;

at each of a third set of predetermined steps of the second plurality of predetermined steps:

projecting an image of a patterned article onto a focal plane of the objective lens;

capturing a third image with a pattern associated with the patterned article and the sample, and storing the third image in a third image array;

at each of a fourth set of predetermined steps of the second plurality of predetermined steps:

capturing a fourth image of the sample without the pattern associated with the patterned article, and storing the fourth image in a fourth image array;

generating a 3D image of the sample by analyzing the third and fourth images; and

subtracting the 3D image of the sample with the 3D image of the reference surface to yield a final 3D image and measurement results of the sample.

Continuity (5)

References Cited (42)