Method of planarizing peripheral circuit region of a DRAM
US6372572B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2001 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Mar 9, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D1/716
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of planarizing the peripheral circuit region of a DRAM. A first oxide layer and a silicon nitride layer are sequentially formed over a substrate. A plurality of polysilicon plugs are formed within the crown-shaped capacitor region of the DRAM. A patterned second oxide layer is formed over the silicon nitride layer. A conformal doped amorphous silicon layer is formed over the exposed surface of the crown-shaped capacitor region and the peripheral circuit region of the DRAM. A photoresist layer is formed over the crown-shaped region and then a nitrogen implant is carried out to form a silicon oxy-nitride barrier layer. A chemical-mechanical polishing is carried out to separate the various lower electrodes. The photoresist layer and the second oxide layer within the crown-shaped capacitor region are removed. Hemispherical silicon grains are grown on the exposed surface of the doped amorphous silicon layer. A dielectric layer and an upper electrode layer are sequentially formed over the hemispherical silicon grains on the doped amorphous silicon layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.