Patent · US Expired

pFET nonvolatile memory

US7221596B2 · kind B2 · utility

25Cited by
60References
129Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 5, 2004
Grant dateMay 22, 2007
Priority date
Expiry dateMay 5, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2216/10
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A nonvolatile memory cell is constructed using a floating-gate (FG) pFET Readout Transistor (RT) having its source tied to a power source (Vdd) and its drain providing a current which can be sensed to determine a cell state. The gate of the RT provides for charge/information storage. A control capacitor structure (CCS) having terminals coupled to a first voltage source and the FG and a tunneling capacitor structure (TCS) having terminals coupled to a second voltage source and the FG are utilized in each embodiment. The CCS has much more capacitance than the TCS. Manipulation of the voltages applied to the first voltage source and second voltage source (and Vdd) controls an electric field across the CCS and pFET dielectrics and thus Fowler-Nordheim tunneling of electrons onto and off of the FG, thus controlling the charge on the FG and the information stored thereon.

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