Low temperature system and method for CVD copper removal
US5897379A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Dec 19, 1997 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | Dec 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/6708
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of using diluted nitric acid and an edge bead removal tool to remove copper from the perimeter of a semiconductor wafer is provided. In one embodiment, sensitive areas of the wafer are covered with photoresist, and the wafer perimeter cleared of photoresist, before the acid is applied. In another embodiment, sensitive areas of the wafer are protected with water spray as the copper etchant is applied. In a third embodiment, the nitric acid is applied to clear the wafer perimeter of copper before a chemical mechanical polishing (CMP) is performed on the layer of deposited copper. The excess thickness of copper protects copper interconnection structures from reacting with the copper etchant. All these methods permit copper to be removed at a low enough temperature that copper oxides are not formed. A semiconductor wafer cleaned of copper in accordance with the above-described method, and a system for low temperature copper removal is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.