发明名称 |
Method for Adaptive Feedback Controlled Polishing |
摘要 |
An adaptive feedback control method is provided for a chemical mechanical polish process to minimize a dielectric layer clearing time difference between two annular regions on a substrate. An optical system with an optical window passes below the polishing pad and detects reflected light interference signals from at least two annular regions. A pre-clearing time difference is determined and is used to calculate an adjustment to one or both of a CMP head membrane pressure and a retaining ring pressure. The pressure adjustment is applied before the end of the polish cycle to avoid the need for a second polish cycle and to reduce a dishing difference and a resistance difference in a metal layer in the at least two annular regions. In some embodiments, a second pressure adjustment is performed before the end of the cycle and different CMP head membrane pressure adjustments are made in different pressure zones. |
申请公布号 |
US2016121451(A1) |
申请公布日期 |
2016.05.05 |
申请号 |
US201414532338 |
申请日期 |
2014.11.04 |
申请人 |
Headway Technologies, Inc. |
发明人 |
Moore Terry;Nease Brant |
分类号 |
B24B37/013;B24B49/12 |
主分类号 |
B24B37/013 |
代理机构 |
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代理人 |
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主权项 |
1. A chemical mechanical polish (CMP) adaptive feedback control method, comprising:
(a) monitoring removal of a dielectric layer from a front side of a substrate during a CMP process by using an optical end point system, the front side of the substrate faces a polishing pad during a polish cycle while a substrate backside adjoins a CMP head membrane and is held in position by a retaining ring, the CMP process also removes a top portion of a metal layer within the dielectric layer; (b) determining a pre-clearing time of the dielectric layer removal for at least two annular regions on the substrate by collecting a reflected light interference signal from a first annular region at a first time (t1) after a polish cycle start time (tS), and collecting a reflected light interference signal from a second annular region at a second time (t2) after tS; (c) calculating an adjustment to one or both of a retaining ring pressure and a CMP head membrane pressure that will minimize a clearing time difference between the first and second annular regions at an end of the polish cycle; (d) applying the adjustment to one or both of the retaining ring pressure and the CMP head membrane pressure; and (e) completing the polish cycle. |
地址 |
Milpitas CA US |