Nitridation for split gate multiple voltage devices
US6331492A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1998 |
| Grant date | Dec 18, 2001 |
| Priority date | — |
| Expiry date | Dec 18, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/981
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for making gate oxides on a silicon wafer surface for multiple voltage applications comprising the steps of growing an oxide layer (12) on a wafer (10) surface, exposing the surface of the oxide layer (12) to a nitrogen ion containing plasma to form a nitrided layer (22). Next, a photoresist layer (14) is deposited over a portion of the oxide layer (12) and the isolation (30), followed by etching of the exposed nitrided layer 22 and a portion of the oxide layer (12) to create a thinner silicon dioxide layer (32). The photoresist layer (14) is removed, the wafer (10) is cleaned and then the thinner silicon dioxide layer (32) is removed prior to a final oxidation step to form a thinner silicon dioxide layer (34) having a different thickness than the silicon dioxide layer (12).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.