STI process by method of in-situ multilayer dielectric deposition
US6235608A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1999 |
| Grant date | May 22, 2001 |
| Priority date | — |
| Expiry date | Apr 14, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/97
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process for forming shallow trench isolation (STI) structures. It includes the steps of: (a) depositing a composite silicon nitride on to the silicon substrate; (b) forming a shallow trench on the silicon substrate by etching, using the composite silicon nitride as the hard mask; (c) depositing a filler oxide layer inside the shallow trench as well as on top of the composite silicon nitride, using a chemical vapor deposition (CVD) method; and (d) using a chemical-mechanical polishing (CMP) process to planarize the filler oxide layer using the composite nitride as a CMP stop. The composite silicon nitride comprises a plurality of silicon nitride layers whose CMP removal rate increases with the distance from the silicon substrate. Additionally, a composite silicon oxide layer can be formed on top of the filler oxide layer which comprises a plurality of silicon oxide layers whose CMP removal rate increases with the distance from the silicon substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.