Inspection system and method for inspecting line width and/or positional errors of a pattern

Patent metadata

Field	Value
Publication number	US-9406117-B2
Application number	US-201514665880-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Apr 9, 2010
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A method and system for imaging an object to be inspected and obtaining an optical image; creating a reference image from design pattern data; preparing an inspection recipe including one or more templates and parameter settings necessary for the inspection; checking the pattern and the template against each other, and selecting the reference image which corresponds to the template; detecting first and second edges in the selected reference image in accordance with the parameter setting using determined coordinates as a reference; detecting first and second edges in the optical image, this optical image corresponds to the selected reference image; and determining an inspection value by acquiring the difference between the line width of the optical image and the reference image using the first edge and second edge of the reference image and the first edge and second edges of the optical image.

First claim

The invention claimed is:

1. A method for inspecting an amount of positional aberration of a pattern on an object to be inspected with different types of patterns rendered thereon, comprising:
imaging the object to be inspected and obtaining optical images;
creating reference images from design pattern data;
preparing an inspection recipe comprising one or more templates used for pattern matching and parameter settings necessary for the inspection;
selecting a pattern of a reference image which corresponds to a template selected from the inspection recipe;
detecting a first edge and a second edge in the selected reference image in accordance with the parameter settings using a standard coordinate;
selecting an optical image which corresponds to the selected reference image;
determining an expected coordinate region within which to search for an edge of the selected pattern based on a matching reference coordinate in the parameter settings that identifies a same reference location in relation to the selected pattern in both of the selected reference image and the selected optical image;
detecting a first edge in the selected optical image corresponding to the first edge in the selected reference image and a second edge in the selected optical image corresponding to the second edge in the selected reference image using the matching reference coordinate to search for at least one of the first edge and the second edge in the selected optical image only within the determined expected coordinate region; and
determining an inspection value by acquiring an amount of positional aberration between the selected optical image and the selected reference image by using the first edge and the second edge of the selected optical image, and the first edge and the second edge of the selected reference image.

2. The method according to claim 1 , comprising:
acquiring the amount of positional aberration of the selected optical image and the selected reference image from the respective middle positions of the first edge and the second edge in the selected optical image and the respective middle position of the first edge and second edge in the selected reference image.

3. The method according to claim 1 , comprising:
determining a pattern corresponding to an inspection value which exceeds a threshold value in inspection recipe is defective.

4. The method according to claim 1 , comprising:
setting the inspection recipe between a plurality of objects to be inspected;
detecting the first edge in the selected reference image and the first edge in the selected optical image corresponding to the first edge in the selected reference image in one object, and, the second edge in the selected reference image and the second edge in the selected optical image corresponding to the second edge in the selected reference image in another object.

5. An inspecting system which illuminates light on to an object to be inspected, receiving optical images of the object to be inspected in an image sensor, and inspecting a pattern rendered on the object to be inspected, said system comprising:
a sensor circuit configured to acquire the optical images from the image sensor;
a pattern generating circuit configured to generate design images data from design pattern data;
a reference circuit configured to create reference images from the design images data; and
a comparison circuit configured to select a pattern of a reference image which corresponds to a template by utilizing an inspection recipe comprising one or more templates used for pattern matching including the template and parameter settings necessary for the inspection, detect a first edge and a second edge in the selected reference image in accordance with the parameter settings using a standard coordinate, select an optical image corresponding to the selected reference image, determine an expected coordinate region within which to search for an edge of the selected pattern based on a matching reference coordinate in the parameter settings that identifies a same reference location in relation to the selected pattern in both of the selected reference image and the selected optical image, detect a first edge in the selected optical image corresponding to the first edge in the selected reference image and a second edge in the selected optical image corresponding to the second edge in the selected reference image using the matching reference coordinate to search for at least one of the first edge and the second edge in the selected optical image only within the determined expected coordinate region, and acquire an inspection value by measuring an amount of positional aberration between the selected optical image and the selected reference image by using the first edge and the second edge in the selected optical image and the first edge and the second edge in the selected reference image.

6. The inspecting system according to claim 5 , wherein the comparison circuit is further configured to determine that a pattern corresponding to an inspection value which exceeds a threshold value in the inspection recipe is defective.

Assignees

• Nuflare Technology Inc

Inventors

• Touya Takanao
• Tamamushi Shuichi
• Sato Hidenori
• Tanizaki Hiroyuki
• Fujiwara Takeshi
• Sawa Eiji
• Okuda Kentaro
• Ikeda Hiroyuki
• Inoue Hiromu
• Tsukada Hiroshi

Classifications

• H10P74/00

  Testing or measuring during manufacture or treatment of wafers, substrates or devices · CPC title

• G01N21/956

  Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} · CPC title

• G06T7/0006

  using a design-rule based approach · CPC title

• G06T7/0085

  Physics · mapped topic

• G06T7/0044

  Physics · mapped topic