Programmable bipolar structures
US4412308A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 15, 1981 |
| Grant date | Oct 25, 1983 |
| Priority date | — |
| Expiry date | Jun 15, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B69/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A switchable bipolar structure, suitable for use in a programmable read only memory, is provided which includes a rectifying contact disposed on a N type semiconductor substrate with a P type diffusion region formed in the substrate spaced within a minority carrier diffusion length from the rectifying contact. A conductive filament is selectively formed between the rectifying contact and the P type diffusion region by applying a reverse bias voltage between the rectifying contact and the N type substrate having a magnitude sufficiently large so as to form a liquid alloy having a front moving in the direction of current flow. By maintaining the P type diffusion region at a positive voltage with respect to the voltage on the rectifying contact, the liquid alloy front moves from the rectifying contact to the P type diffusion region forming a conductive filament or segment therebetween. If the rectifying contact is aluminum and the semiconductor substrate is made of silicon, the filament becomes a silicide made of aluminum and silicon. By arranging the rectifying contact within a minority carrier diffusion length of, e.g., the base of a NPN transistor, a dense programmable read only me…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.