Programming a Static Random-Access Memory Cell With Hot Electrons
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
By injecting hot electrons into the gate region of a field-effect transistor (FET) structure, a simple technique for personalizing chips for redundancy, architecture, organization or initial shadow programs can be provided. A CMOS FET static random-access memory (SRAM) cell with matched devices will, in the ideal case, assume random states upon the application of voltage to the cell. Through the injection of hot electrons into the gate insulator of an FET SRAM cell, it is possible to cause a threshold voltage shift so that each time the cell is powered on it will assume a preferred state. In actual use, a normal gate input signal will override the preferred state when the cell is addressed and can be set to either binary state. Fig.