Patent · US Expired

Semiconductor device

US8054680B2 · kind B2 · utility

18Cited by
11References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 25, 2004
Grant dateNov 8, 2011
Priority date
Expiry dateMay 25, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C16/3468
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Memory cells in which an erase and write operation is performed by injecting electrons from a substrate and extracting the electrons into a gate electrode constitute a semiconductor nonvolatile memory device. That is a gate extraction semiconductor nonvolatile memory device. In that device, if an erase bias is applied in a first process of an erase and write operation, memory cells in an overerase condition occur and the charge retention characteristics of such memory cells are degraded. The present invention provides a semiconductor nonvolatile memory device using means for writing all the memory cells in an erase unit before applying the erase bias, and then applying the erase bias.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.