Nonvolatile semiconductor memory device and method for driving the same
US6657893B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2002 |
| Grant date | Dec 2, 2003 |
| Priority date | — |
| Expiry date | Jan 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B69/00
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory transistor and a select transistor are disposed side by side on a semiconductor substrate between source/drain diffusion layers thereof, with an intermediate diffusion layer interposed therebetween. The memory transistor includes: a gate insulating film having such a thickness as to allow tunneling current to pass therethrough; a floating gate electrode; an interelectrode insulating film; and a control gate electrode. The select transistor includes a gate insulating film and a select gate electrode. Tunneling current, allowing electrons to pass through the gate insulating film under the floating gate electrode, is utilized during the removal and injection of electrons from/into the floating gate electrode. As a result, higher reliability can be attained and rewriting can be performed at a lower voltage. Also, since the select transistor is provided, reading can also be performed at a lower voltage. Improvement of reliability and rewrite and read operations at respective lower voltages are realized for a nonvolatile semiconductor memory device, in which a memory cell includes a floating gate electrode and a control gate electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.