Method of chemical mechanical polishing (CMP) using an underpad with different compression regions and polishing pad therefor
US5899745A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1997 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Jul 3, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31053
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A chemical mechanical polishing (CMP) method utilizes a polishing pad (21) and an under pad (20). The under pad (20) has an edge portion (24) and a central portion (22). The central portion (22) has either a shore D hardness less than a shore D hardness of the portion (24), greater slurry absorption than the edge portion (24), or more compressibility than the edge portion (24). This composite material under pad (20) will improve polishing uniformity of a semiconductor wafer (39). In addition, the use of the polishing pads (20 and 21) allows for greater final wafer profile control than was previously available in the art (FIGS. 4-6).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.