Processing for polishing dissimilar conductive layers in a semiconductor device
US6204169A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1997 |
| Grant date | Mar 20, 2001 |
| Priority date | — |
| Expiry date | Mar 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process of polishing two dissimilar conductive materials deposited on semiconductor device substrate optimizes the polishing of each of the conductive material independently, while utilizing the same polishing equipment for manufacturing efficiency. A tungsten layer (258) and a titanium layer (256) of a semiconductor device substrate (250) are polished using one polisher (10) but two different slurry formulations. The two slurries can be dispensed sequentially onto the same polishing platen (132) from two different urce containers (111 and 112), wherein the first slurry is dispensed until e tungsten is removed and then the slurry dispense is switched to second slurry for removal of the titanium. In a preferred embodiment, the first slurry composition is a ferric nitrate slurry while the second slurry composition is an oxalic acid slurry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.