Holding apparatus, a metal deposition system, and a wafer processing method which preserve topographical marks on a semiconductor wafer
US5456756A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1994 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Sep 2, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2223/54493
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A holding apparatus, a metal deposition system and a wafer processing method which preserve topographical marks, including those used as alignment targets, on a semiconductor wafer by preventing metal from depositing on such marks during metal deposition. The invention eliminates the need to use window mask and etch techniques to provide replication of topographical marks on a newly formed metal layer when a CMP planarization technique is used prior to metal deposition. As a result, cost, cycle time and yield loss due to the additional window mask and etch steps can be eliminated. The holding apparatus includes a wafer retainer for retaining a wafer which has at least one topographical mark and a clamp ring with at least one tab. The wafer is pressed against the clamp ring by the retainer for securing the wafer in the retainer. Each tab is positioned directly above a corresponding one of the topographical mark and has an area big enough to cover such mark for avoiding metal being deposited on such mark during metal deposition of the wafer. The metal deposition system comprises a depositing system for depositing a layer of a selected metal onto the wafer. The metal deposition system…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.