Semiconductor device for performing photoelectric conversion
US8415762B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2007 |
| Grant date | Apr 9, 2013 |
| Priority date | — |
| Expiry date | Mar 26, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/401
Abstract
The external base electrode has a two-layered structure where a p-type polysilicon film doped with a medium concentration of boron is laminated on a p-type polysilicon film doped with a high concentration of boron. Therefore, since the p-type polysilicon film doped with a high concentration of boron is in contact with an intrinsic base layer at a junction portion between the external base electrode and the intrinsic base layer, the resistance of the junction portion can be reduced. In addition, since the resistance of the external base electrode becomes a parallel resistance of the two layers of the p-type polysilicon films, the resistance of the p-type polysilicon film whose boron concentration is relatively lower is dominant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.