Patent ID: 7656704
Filing Date: 2010-02-02
Classification: G11C

Abstract:
1. A method for programming a multi-level nitride storage memory cell including a nitride storage region that stores different programming states corresponding to a plurality of threshold voltage levels, comprising: selecting a resistor from a variable resistance circuit including a plurality of exclusively selectable resistors having different resistance values and a direct connection to provide a zero magnitude resistance, each resistor having a predetermined magnitude and corresponding directly to one of the plurality of threshold voltage levels, and at least one of the resistors having a value in the range of 1 k ohm to 20 k ohm; connecting a drain side of the nitride storage memory cell to the selected resistor; and programming the nitride storage memory cell to store one of the program states corresponding to the one of the threshold voltage levels by applying a programming voltage to the drain side through the selected resistor.