Slurry compositions and method for the chemical-mechanical polishing of copper and copper alloys
US6083840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Nov 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to an improved chemical-mechanical polishing (CMP) method for polishing a copper coated wafer containing a copper adhesion-promoting layer and a silicon-based layer. The method polishes copper layers with high removal rates, low defect densities and reduced amounts of dishing and erosion. The method involves a two step process. The first step is to utilize a bulk copper removal slurry that rapidly removes the majority the copper on the substrate. The second step utilizes a 1:1:1 selectivity copper/tantalum/silicon dioxide (Cu/Ta/SiO.sub.2) slurry that has approximately the same polishing rates for the copper layer, the adhesion-promoting layer and the silicon-based substrate. The second slurry reduces the amount of dishing and erosion that occurs in the copper trenches and dense copper arrays.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.