Process for forming silicided capacitor utilizing oxidation barrier layer
US6171901A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 1999 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | Jul 16, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/692
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A process flow for forming a polysilicon-to-polysilicon capacitor performs the capacitor anneal step in a nitrous oxide ambient. As a result, a nitroxide layer forms over heavily doped polysilicon of the upper electrode of the capacitor. This nitroxide layer acts as a barrier against the diffusion of oxygen, preventing further oxidation of the heavily doped polysilicon electrode layer during the subsequent seal oxidation step. The nitroxide barrier layer is readily removed along with the other seal oxide layers immediately before formation of the silicided capacitor electrode contacts, without any attendant danger of overetching of gate oxide or spacer structures. Where the gate polysilicon layer is doped immediately after its formation, an additional capacitor anneal step in a nitrous oxide ambient is necessary to form an additional nitroxide layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.