Semiconductor ROM cell programmed using source mask
US5200802A · kind A · utility
11Cited by
11References
22Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 22, 1992 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | Jun 22, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B20/00
Abstract
ROM cell programmed ON has N+ source implant spaced a given distance from the gate with LDD bridging the gap between the N+ source and the N channel. ROM cell programmed OFF has P+ implanted into this gap so as to completely override the LDD in this gap. The P+ prevents the N channel from forming ohmic connection to the N+ source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.