Method and system of discriminating substrate type

• US 7,211,196 B2
• Filed: 03/26/2004
• Issued: 05/01/2007
• Est. Priority Date: 03/26/2004
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Lam, Hieu A., Yue, Hongyu
• Primary Examiner(s): ALANKO, ANITA KAREN
• Application Number:
  US10/809,474
• Publication Number:
  US 20050211669A1
• Time in Patent Office: 1,131 Days
• Field of Search: None
• US Class Current: 216/59
• CPC Class Codes: G01N 21/68 using high frequency electric fields

Abstract

A method and system for determining a substrate type during a seasoning process is presented. An optical signal is acquired from a process in a plasma processing system, and the optical signal is compared to a pre-determined threshold value. Depending upon the comparison, the substrate type is determined to be of a correct type, or an incorrect type.

Claims

1. A method for determining a substrate type comprising:

disposing said substrate in a plasma processing system;

exposing said substrate to a plasma process in said plasma processing system;

detecting an optical signal resulting from an optical emission spectrum of said plasma process performed on said substrate, said optical signal including an intensity ratio of a first intensity corresponding to a first wavelength band to a second intensity corresponding to a second wavelength band; and

determining whether said substrate type is a correct substrate type or an incorrect substrate type by comparing said optical signal with a threshold value,

said threshold value comprises setting said threshold value to an average of an intensity ratio corresponding to the incorrect substrate type and an intensity ratio corresponding to the correct substrate type.

2. The method of claim 1, wherein said exposing said substrate to said process comprises exposing said substrate to a seasoning process.

3. The method of claim 1, wherein said detecting said optical signal comprises using optical emission spectroscopy (OES).

4. The method of claim 1, wherein said determining said substrate type comprises determining the correct substrate type when said intensity ratio has a value less than said threshold value, and determining the incorrect substrate type when said intensity ratio has a value greater than said threshold value.

5. The method of claim 1, wherein said determining said substrate type comprises identifying a seasoning substrate when said intensity ratio has a value less than said threshold value, and identifying a bare silicon substrate when said intensity ratio has a value greater than said threshold value.

6. The method of claim 1, wherein said comparing said optical signal with said threshold value comprises comparing said optical signal with at least one of a static threshold value, or a dynamic threshold value.

8. The method of claim 1, wherein said exposing said substrate to said process comprises exposing said substrate to a production process.

7. A method for determining a substrate type comprising:

disposing said substrate in a plasma processing system;

exposing said substrate to a seasoning process in said plasma processing system;

detecting an optical signal resulting from an optical emission spectrum of said process using optical emission spectroscopy, wherein said optical signal comprises an intensity ratio of a first intensity corresponding to a first wavelength band to a second intensity corresponding to a second wavelength band; and

determining whether said substrate is a correct substrate type or an incorrect substrate type by comparing said optical signal with a threshold value, wherein said threshold value is set to an average value between an intensity ratio for the correct substrate type and an intensity ratio for the incorrect substrate type.