LCD TFT having two layer region adjacent base region in which the layers have opposite conductivities and have two density gradients
US5710606A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 1995 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Aug 22, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/6715
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A polycrystalline silicon active layer is provided on a transparent insulating substrate. Phosphorus is ion-implanted into the active layer, to form a pair of n-type source/drain regions with a base region interposed therebetween. In this ion-implantation, a density gradient of phosphorus is formed in the thicknesses direction of the active layer. Boron is ion-implanted into each of the source/drain regions, to be adjacent to the base region. In this ion-implantation, a density gradient of boron is formed, and the position providing a maximum density of boron is set to be deeper than the position which provides a maximum density of phosphorus. By the ion-implantation of boron, an n-type LDD portion having a high resistance and a p-type portion are formed on the upper and lower sides, respectively, adjacent to the base region within each of the source/drain regions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.