Patent ID: 6964597
Filing Date: 2005-11-15
Classification: B24B

Abstract:
1. A retaining ring for chemical mechanical polishing (CMP) apparatus comprising: a body of said retaining ring; and a single trigger cavity; said single trigger cavity further including: wherein said trigger cavity is formed inside said body of said retaining ring; and wherein said trigger cavity is configured to indicate that thickness of said retaining ring is less than or equal to a predetermined thickness threshold, and wherein said single trigger cavity extends inside said body of said retaining ring at a depth level that is greater than or equal to a threshold depth level corresponding to a predetermined thickness threshold; and wherein said single trigger cavity is filled with gas; and wherein said O-ring prevents said gas from escaping from said trigger cavity; and wherein said gas is selected from the group consisting of: {air, Helium, Neon, Argon, Krypton, and Xenon}.