Chemical-mechanical polishing for shallow trench isolation
US5958795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1998 |
| Grant date | Sep 28, 1999 |
| Priority date | — |
| Expiry date | May 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76229
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of chemical-mechanical polishing for forming a shallow trench isolation. A substrate having a plurality of active regions, including a large active region and a small active region, is provided. A silicon nitride layer is formed on the substrate. A shallow trench is formed between the active regions. An oxide layer is formed over the substrate, so that the shallow trench is filled therewith. A partial reverse active mask is formed on the oxide layer, so that the oxide layer on a central part of the large active region is exposed. Whereas, the oxide layer on an edge part of the large active region and on the small active region are covered by the partial reverse active mask. The oxide layer is etched with the silicon nitride layer as a stop layer, using the partial reverse active mask as a mask. The oxide layer is planarized until the oxide layer within the shallow trench has a same level as the silicon nitride layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.