Semiconductor memory device and manufacturing method thereof
US6169308A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1998 |
| Grant date | Jan 2, 2001 |
| Priority date | — |
| Expiry date | Oct 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/681
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
A high speed/large capacity DRAM (Dynamic Random Access Memory) is generally refreshed each 0.1 sec because it loses information stored therein due to a leakage current. The DRAM also loses information stored therein upon cutoff of a power source. Meanwhile, a nonvolatile ROM (Read-only Memory) cannot be configured as a high speed/large capacity memory. A semiconductor memory device of the present invention realizes nonvolatile characteristic by shielding a drain functioning as a memory node from a leakage current by a tunnel insulator, and also realizes stable and high speed operation by adding a transistor for reading to a memory cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.