Method of fabricating deep trench capacitor
US6423594B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 2001 |
| Grant date | Jul 23, 2002 |
| Priority date | — |
| Expiry date | Jan 4, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/0385
Abstract
A method of fabricating a trench capacitor includes forming a trench in a substrate; forming a conductive diffusion region in the substrate surrounding a lower portion of the trench; forming a dielectric layer along an inner surface of the trench; and filling the trench with a first doped polysilicon layer. A first recess is formed to expose an upper portion of the inner sidewall of the trench. A collar dielectric layer is formed on the exposed inner sidewall. The first recess is filled with a second doped polysilicon layer. A second recess is formed to expose a part of the upper portion of the inner sidewall. A gap is formed between the exposed inner sidewall and the second doped polysilicon layer, and filled with a doped polysilicon layer converted from an undoped polysilicon layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.