Patent ID: 6046934
Filing Date: 2000-04-04
Classification: G11C

Abstract:
A program and verify method for programming a multi-level threshold memory cell device via controlled regulation of the gate voltage, the device including a floating gate memory cell having a cell current and threshold voltage, the memory cell switchably coupled with at least one dummy cell having a respective cell current and threshold voltage, the threshold voltage of the dummy cell being set to a target threshold level of the memory cell, the cells having common drain, gate, and source nodes, the method comprising the steps of:coupling the drain and gate nodes to a high voltage level, and the source node to a certain intermediate voltage level, for each of a series of program pulses applied;repeating the application of the program pulses, and thereafter verify voltage pulses, to the gate, drain, and source nodes until the programmable threshold voltage level of the memory cell reaches the target threshold voltage.