Geometrical control of device corner threshold
US5858866A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1996 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Nov 22, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S977/938
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Corner conduction in a conduction channel of a field effect transistor is controlled by the geometrical configuration of the gate oxide and gate electrode at the sides of the conduction channel. Rounding the corners of the conduction channel or forming depressions at edges of trench structures such as deep or shallow trench isolation structures and/or trench capacitors develop recesses in a surface of a substrate at an interface of active areas and trench structures in which a portion of the gate oxide and gate electrode are formed so that the gate oxide and gate electrode effectively wrap around a portion of the conduction channel of the transistor. Particularly when such transistors are formed in accordance with sub-micron design rules, the geometry of the gate electrode allows the electric field in the conduction channel to be modified without angled implantation to regulate the effects of corner conduction in the conduction channel. Thus the conduction characteristic near cut-off can be tailored to specific applications and conduction/cut-off threshold voltage can be reduced at will utilizing a simple, efficient and high-yield manufacturing process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.