Yizhi Xiong

US Patent:

6565416, May 20, 2003

Filed:

Mar 13, 2001

Appl. No.:

09/805860

Inventors:

Samuel Vance Dunton - San Jose CA
Yizhi Xiong - Santa Clara CA

Assignee:

Koninklijke Philips Electronics N.V. - Eindhoven

International Classification:

B24B 4900

US Classification:

451 6, 451 8, 451 57, 451 66

Abstract:

A multi-platen chemical-mechanical polishing system is used to polish a wafer. The wafer is polished at a first station. During polishing, an endpoint is detected. The endpoint is detected by generating optical radiation by a first light source. The first optical radiation travels through a translucent area in a surface of a first platen and travels through a first polishing pad. After being reflected by the wafer, the optical radiation returns through the first polishing pad through the translucent window to a first optical radiation detector. The first polishing pad has a uniform surface in that no part of the surface of the first polishing pad includes transparent material through which non-scattered optical radiation originating from the first light source can pass and be detected by the first optical radiation detector. Optical radiation that travels through the first polishing pad and is detected by the first optical radiation detector is haze scattered by inclusions within the first polishing pad. Non-scattered light is absorbed by the first polishing pad.

US Patent:

62244604, May 1, 2001

Filed:

Jun 30, 1999

Appl. No.:

9/340487

Inventors:

Samuel Vance Dunton - San Jose CA
Yizhi Xiong - Santa Clara CA

Assignee:

VLSI Technology, Inc. - San Jose CA

International Classification:

B24B 4900
B24B 5100

US Classification:

451 6

Abstract:

A multi-platen chemical-mechanical polishing system is used to polish a wafer. The wafer is polished at a first station. During polishing, an endpoint is detected. The endpoint is detected by generating optical radiation by a first light source. The first optical radiation travels through a translucent area in a surface of a first platen and travels through a first polishing pad. After being reflected by the wafer, the optical radiation returns through the first polishing pad through the translucent window to a first optical radiation detector. The first polishing pad has a uniform surface in that no part of the surface of the first polishing pad includes transparent material through which non-scattered optical radiation originating from the first light source can pass and be detected by the first optical radiation detector. Optical radiation that travels through the first polishing pad and is detected by the first optical radiation detector is haze scattered by inclusions within the first polishing pad. Non-scattered light is absorbed by the first polishing pad.