Bucket brigade charge transfer device with auxiliary gate electrode
US4709380A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 6, 1986 |
| Grant date | Nov 24, 1987 |
| Priority date | — |
| Expiry date | Jan 6, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C19/186
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A high charge transfer efficiency BBD (bucket brigade device) has an auxiliary gate (M.sub.11, M.sub.12 . . . ) provided in a position next to each transfer gate (11, 12 . . . ) of a charge transfer MOSFET, the auxiliary gate being impressed with a DC bias voltage. A region of higher absolute value of threshold voltage at the auxiliary gate electrode is formed, by making the gate insulation film thereat (241, 242 . . . ) thicker than other parts, or by forming a higher doped island region (211, 212) than the substrate surface under the transfer gate. This enables the attainment of efficient charge transfer by only impressing the same DC bias level on the auxiliary gates (M.sub.11, M.sub.12 . . . ) as the voltage of the clock signal level for the transfer gates (11, 12 . . . ).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.