Thin film memory cell
US5278428A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1991 |
| Grant date | Jan 11, 1994 |
| Priority date | — |
| Expiry date | Jun 25, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/69
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory cell has a thin film memory transistor and a thin film selective transistor. The thin film memory transistor has a charge trapping structure and a positive-negative-charge occurrence structure. The charge trapping structure includes a first thin film semiconductor layer, an insulating memory gate layer formed on the first thin film semiconductor layer, and a memory gate electrode. The positive-negative-charge occurrence structure includes an impurity high density layer with a portion facing the memory gate electrode. The thin film selective transistor is coupled to the thin film memory transistor in a serial form and has an only n-channel occurrence structure which includes a second thin film semiconductor layer, an insulating selective gate layer formed on the second thin film semiconductor layer and being thicker than the insulating memory gate layer, and a selective gate electrode formed on said insulating selective gate layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.