Removal of field and embedded metal by spin spray etching
US5486234A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1995 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | Jan 19, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32134
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process of removing both the field metal, such as copper, and a metal, such as copper, embedded into a dielectric or substrate at substantially the same rate by dripping or spraying a suitable metal etchant onto a spinning wafer to etch the metal evenly on the entire surface of the wafer. By this process the field metal is etched away completely while etching of the metal inside patterned features in the dielectric at the same or a lesser rate. This process is dependent on the type of chemical etchant used, the concentration and the temperature of the solution, and also the rate of spin speed of the wafer during the etching. The process substantially reduces the metal removal time compared to mechanical polishing, for example, and can be carried out using significantly less expensive equipment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.