Transistors formed with grid or island implantation masks to form reduced diffusion-depth regions without additional masks and process steps
US6869851B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 2004 |
| Grant date | Mar 22, 2005 |
| Priority date | — |
| Expiry date | Jan 20, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/038
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming two regions having differing depths using a single implantation process is provided. A mask having two openings associated therewith is formed over a semiconductor body, wherein one of the openings has a size larger than an implantation design rule, and the other opening has a size smaller than the design rule. An implant is performed into the semiconductor body through the implant mask, resulting in two distinct doped regions, wherein the region associated with the larger opening has more dopant than the region associated with the smaller opening. Subsequent activation and thermal processing results in the one region diffusing a greater amount than the second region, thereby resulting in two regions formed concurrently having different depths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.