Two-step strap implantation of making deep trench capacitors for DRAM cells
US6291286A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Nov 27, 1998 |
| Grant date | Sep 18, 2001 |
| Priority date | — |
| Expiry date | Nov 27, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B12/0385
Abstract
A method of fabricating deep trench capacitors of high density Dynamic Random Access Memory (DRAM) cells is disclosed: first, providing a semiconductor substrate, and then forming a trench on the semiconductor substrate; sequentially forming a capacitor dielectric layer, a first polysilicon storage node, dielectric collars and a second polysilicon stud inside the trench; performing two-step ion implantation to form shallow and deep strap regions on one side of the trench; forming a third polysilicon layer and an isolation layer overlaying the dielectric collars and second polysilicon stud inside the trench to complete a buried strap formation; and forming an access field effect transistor on the semiconductor substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.