Method and apparatus for evaluating the runability of a photomask inspection tool

• US 6,721,695 B1
• Filed: 11/20/2001
• Issued: 04/13/2004
• Est. Priority Date: 03/24/2000
• Status: Expired due to Fees

• Current Assignee: Toppan Photomasks Incorporated (TOPPAN Holdings, Inc.)
• Original Assignee: DuPont Photomasks Inc (TOPPAN Holdings, Inc.)
• Inventors: Chen, Xiaoming, Kalk, Franklin Dean, Chipman, Paul, Howard, Charles H., Son, Kong
• Primary Examiner(s): Broda, Esq., Samuel
• Application Number:
  US09/989,509
• Time in Patent Office: 875 Days
• Field of Search: 703/1-2, 703/7, 703/22, 382/144, 382/152, 702/35, 702/94, 430/5, 430/30, 430/22, 356/237, 356/239
• US Class Current: 703/7
• CPC Class Codes: G03F 1/84 Inspecting

Abstract

A method and apparatus evaluates the runability of a photomask inspection tool that inspects plural sets of die, each die having a standard simulated industrial device feature at plural technology nodes. A technology node size is determined for each feature at which inspection by the tool provides no false detection of faults. A sensitivity module included on a photomask test plate along with a runability module allows determination of inspection tool sensitivity and runability in a single test sequence.

Claims

1. An apparatus for evaluating the runability of a photomask inspection tool, the apparatus comprising:

a photomask test plate; and

plural die written on the test plate, each die having repeated occurrences of a feature written at a technology node;

wherein inspection of the plural die with the tool provides a determination of the smallest technology node at which the tool identifies a feature without detecting false defects.

2. The apparatus of claim 1 further comprising:

a sensitivity module written on the test plate for determining the smallest defect that the tool can detect.

3. The apparatus of claim 1 wherein the plural die are written as an array having columns with each die in a column having repeated occurrences of the same feature, the array having rows with each die in a row having repeated occurrences of a feature at the same technology node.

4. The apparatus of claim 3 wherein the plural die are written as a first and second array for die-to-die comparison inspection.

5. The apparatus of claim 3 further comprising:

a sensitivity module having a transmission defect.

6. An apparatus for evaluating the runability of a photomask inspection tool, the apparatus comprising:

a photomask test plate; and

a runability module written on the test plate, the runability module including plural features at plural technology nodes;

wherein the runability module facilitates a determination by the inspection tool of the smallest technology node at which a feature is identified without the tool detecting false errors.

7. The apparatus of claim 6 further comprising:

a sensitivity module written on the test plate, the sensitively module operable to determine the smallest defect that the tool can detect.

8. The apparatus of claim 6 further comprising the plural features formed in plural die in the runability module.

9. The apparatus of claim 8 further comprising the plural die written as an array including:

columns with each die in a column having repeated occurrences of the same feature; and

rows with each die in a row having repeated occurrences of the same technology node.

10. The apparatus of claim 9 further comprising the plural die written as a first and second array for die-to-die comparison inspection between a die in the first array and a corresponding die in the second array.