Method of generating a compensation matrix during a substrate inspection

Patent metadata

Field	Value
Publication number	US-10151705-B2
Application number	US-201415021341-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Sep 12, 2013
Publication date	Dec 11, 2018
Grant date	Dec 11, 2018

Abstract

The present invention relates to a method for generating a compensation matrix during a substrate inspection. The method comprises the steps of: selecting information of N1 (N1≥2) feature objects which are randomly predetermined within a field of view (FOV) on a substrate; generating a first compensation matrix on the basis of information of the feature objects which are extracted on the substrate; comparing an offset value of each of all the feature objects with a predetermined reference value by applying all the feature objects within the FOV to the compensation matrix to count the number of the feature objects of which the offset value of the each of all the feature objects is less than the predetermined reference value; and repeatedly performing the above steps N2 times (N2≥1), and generating a second compensation matrix using information of the feature objects which have the offset value which is less than the predetermined reference value, in case the number of the counted feature objects is the maximum.

First claim

The invention claimed is:

1. A method of compensating position information of a field of view (FOV) on a substrate during a substrate inspection by a substrate inspection apparatus, the method comprising:
determining the FOV based on an image-capturing range of a camera of the substrate inspection apparatus;
selecting, by a computer and a computer program, feature objects within the FOV of the substrate;
generating, by the computer and the computer program, a first compensation matrix on a basis of information of the selected feature objects within the FOV and storing the first compensation matrix in a memory section;
obtaining an offset value of each of the selected feature objects within the FOV by applying the selected feature objects to the first compensation matrix and storing the offset value in the memory section;
comparing, by the computer and the computer program, offset values of the selected feature objects with reference values of the selected feature objects;
obtaining effective feature objects from the selected feature objects within the FOV, wherein the effective feature objects are ones of the selected feature objects of which offset values are less than the reference values thereof;
repeatedly performing, by the computer and the computer program, the above steps N times (N≥1) on the FOV to count a number of effective feature objects in each time and determine a maximum number among counted numbers at the N times;
generating, by the computer and the computer program, a second compensation matrix using information of effective feature objects of which number is determined as the maximum number and storing the second compensation matrix in the memory section;
compensating, by the computer and the computer program, the position information of the FOV on the substrate with the second compensation matrix to be same as position information of an exact area intended to be inspected; and
a display section that displays operation status and result of the substrate inspection by the substrate inspection apparatus.

2. The method of claim 1 , further comprising:
(a) obtaining an offset value of each of the selected feature objects by applying the selected feature objects to the second compensation matrix;
(b) comparing, by the computer and the computer program, offset values obtained in step (a) with the reference values of the selected feature objects;
(c) obtaining effective feature objects from the selected feature objects, the effective feature objects having offset values less than the reference values thereof;
(d) repeatedly performing steps (a) through (c) M times (M≥1) on the FOV to count a number of effective feature objects in each time and determine a maximum number among counted numbers at the M times;
(e) generating, by the computer and the computer program, a third compensation matrix on a basis of information of effective feature objects of which number is determined as the maximum number in step (d); and
(f) compensating the position information of the FOV on the substrate with the third compensation matrix.

3. The method of claim 1 , wherein the first compensation matrix and the second compensation matrix are one of an affine transformation matrix or a projective transformation matrix.

4. The method of claim 1 , wherein the N is determined by following equation,

N
⁢

⁢
2

=

log
⁡

(

1
-
p

)

log
⁡

(

1
-

u

N
⁢

⁢
1

)

wherein ‘p’ is a probability of selecting only feature objects of which offset values are less than the specific offset values when N 1 feature objects are selected, and ‘u’ is a probability of being a feature object of which offset value is less than the specific offset value when one feature object is selected.

5. The method of claim 1 , wherein the feature object is at least one of a hole pattern, a circle pattern and a corner portion of a curved pattern.

6. A non-transitory computer-readable media storing program instructions for performing a computer implemented method for compensating position information of a field of view (FOV) on a substrate during a substrate inspection by a substrate inspection apparatus, wherein the computer implemented method comprises:
determining the FOV based on an image-capturing range of a camera of the substrate inspection apparatus;
selecting, by a computer and a computer program, feature objects within the FOV of the substrate;
generating, by the computer and the computer program, a first compensation matrix on a basis of information of the selected feature objects within the FOV and storing the first compensation matrix in a memory section;
obtaining an offset value of each of the selected feature objects within the FOV by applying the selected feature objects to the first compensation matrix and storing the offset value in the memory section;
comparing, by the computer and the computer program, offset values of the selected feature objects with reference values of the selected feature objects;
obtaining effective feature objects from the selected feature objects within the FOV, wherein the effective feature objects are ones of the selected feature objects of which offset values are less than the reference values thereof;
repeatedly performing, by the computer and the computer program, the above steps N times (N≥1) on the FOV to count a number of effective feature objects in each time and determine a maximum number among counted numbers at the N times;
generating, by the computer and the computer program, a second compensation matrix using information of effective feature objects of which number is determined as the maximum number and storing the second compensation matrix in the memory section;
compensating, by the computer and the computer program, the position information of the FOV on the substrate with the second compensation matrix to be same as position information of an exact area intended to be inspected; and
a display section that displays operation status and result of the substrate inspection by the substrate inspection apparatus.

Assignees

• Koh Young Tech Inc

Inventors

• Jung Seungwon
• Choi Jongjin
• You Heewook

Classifications

• G06T2207/30141

  Printed circuit board [PCB] · CPC title

• G01N2021/8896

  Circuits specially adapted for system specific signal conditioning · CPC title

• G06T2207/20076

  Probabilistic image processing · CPC title

• G01N2201/121

  Correction signals · CPC title

• G01N21/95607 Primary

  using a comparative method · CPC title