Semiconductor device and method for manufacturing the same
US7902003B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2007 |
| Grant date | Mar 8, 2011 |
| Priority date | — |
| Expiry date | May 21, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02691
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An image display device capable of high-resolution and smooth moving image display, equipped with TFTs in an n-type (or p-type) semiconductor layer with a high on-off ratio and a low resistance. In polysilicon crystallization by laser annealing, an n-type (or p-type) semiconductor layer with a low resistance is produced by performing the following processes in order: implanting nitrogen (N) ions into an amorphous silicon precursor semiconductor film; laser crystallization; implanting n-type (or p-type) dopant ions; and annealing for dopant activation. When fabricating TFTs, this low-resistance semiconductor layer is used to form a source and a drain. Since C, N, and O impurities decrease the mobility of the TFTs, polysilicon is used in which the contaminants concentrations meet the following conditions: carbon concentration ≦3×1019 cm−3, nitrogen concentration ≦5×1017 cm−3, and oxygen concentration ≦3×1019 cm−3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.