Charge transfer memory and fabrication method thereof
US4878103A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Oct 31, 1989 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C19/287
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A charge transfer memory and its fabrication method are disclosed. The memory has charge transfer shift registers, with four phases and two level of electrodes, and a reading register with two phases and three levels of electrodes. At one end of each shift register, there is a final electrode contiguous with a reading storage electrode of the reading register, which is itself contiguous to a reading transfer electrode. These electrodes are made in a layer, with a second type of doping, of a semiconductor substrate with a first type of doping. Zones with a third type of doping are made facing the transfer electrodes of the reading register. According to the invention, facing the final electrode of each shift register, a zone with a fourth type of doping is made. This zone with a fourth type of doping prevents charges flowing in the reading register from returning to a shift register.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.