Method and apparatus for inspecting pattern defects

• US 8,275,190 B2
• Filed: 08/22/2011
• Issued: 09/25/2012
• Est. Priority Date: 11/20/2003
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Sakai, Kaoru, Maeda, Shunji, Okabe, Takafumi
• Primary Examiner(s): Desire, Gregory M
• Application Number:
  US13/214,420
• Publication Number:
  US 20110304725A1
• Time in Patent Office: 400 Days
• Field of Search: 348/87, 348/92, 348/126, 356/237.4, 356/237.5, 382/144, 382/149, 382/195, 382/218, 382/224, 700/121
• US Class Current: 382/149
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G01N 21/95607 using a comparative method
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

An apparatus for inspecting pattern defects, the apparatus including: an image acquisition unit which acquires an image of a specimen and stores the acquired image in an image memory; a defect candidate extraction unit which performs a defect candidate extraction process by using the acquired image, which is read from the image memory; and a defect detection unit which performs a defect detection process based on a partial image containing a defect candidate that is extracted by the defect candidate extraction unit, wherein the defect detection process performed by the defect detection unit is performed asynchronously with an image acquisition process that is performed by the image acquisition unit.

Claims

1. An apparatus for inspecting pattern defects, the apparatus comprising:

an image acquisition unit which acquires an image of a specimen and stores the acquired image in an image memory;

a defect candidate extraction unit which performs a defect candidate extraction process by using the acquired image, which is read from the image memory; and

a defect detection unit which performs a defect detection process based on a partial image containing a defect candidate that is extracted by the defect candidate extraction unit,

wherein the defect detection process performed by the defect detection unit is performed asynchronously with an image acquisition process that is performed by the image acquisition unit.

2. The apparatus for inspecting pattern defects according to claim 1,

wherein the image acquisition unit is installed in a clean room and the defect detection unit is installed outside the clean room.

3. The apparatus for inspecting pattern defects according to claim 1,

wherein the defect detection unit includes plural defect detection sets, each of the plural defect detection sets performs the defect detection process in parallel on partial images which are different with each other.

4. The apparatus for inspecting pattern defects according to claim 1,

wherein the defect detection unit includes a comparative collation section, which detects defects by collating feature amount of the defect candidate calculated by the defect candidate extraction unit with feature amount of the defect candidate calculated by the defect detection unit.

5. The apparatus for inspecting pattern defects according to claim 1,

wherein the image acquisition unit includes plural TDI image sensors.

6. An apparatus for inspecting pattern defects, the apparatus comprising:

an image acquisition unit which acquires an image of a specimen and stores the acquired image in an image memory;

a defect candidate extraction unit which performs a defect candidate extraction process by using the acquired image, which is read from the image memory; and

a defect detection unit which performs a defect detection process based on a partial image containing a defect candidate that is extracted by the defect candidate extraction unit,

wherein the defect detection process performed by the defect candidate extraction unit and the defect detection unit are performed off-line asynchronously with an image acquisition process that is performed by the image acquisition unit.

7. The apparatus for inspecting pattern defects according to claim 6,

wherein the image acquisition unit is installed in a clean room, and the defect candidate extraction unit and the defect detection unit are installed outside the clean room.

8. The apparatus for inspecting pattern defects according to claim 6,

wherein the defect candidate extraction unit includes plural defect candidate extraction sets, each of the plural defect candidate extraction sets performs the defect candidate extraction process in parallel on partial images which are different with each other;

and

wherein the defect detection unit includes plural defect detection sets, each of the plural defect detection sets performs the defect detection process in parallel on partial images which are different with each other.

9. The apparatus for inspecting pattern defects according to claim 6,

wherein the defect detection unit includes a comparative collation section, which detects defects by collating feature amount of the defect candidate calculated by the defect candidate extraction unit with feature amount of the defect candidate calculated by the defect detection unit.

10. The apparatus for inspecting pattern defects according to claim 6,

wherein the image acquisition unit includes plural TDI image sensors.