Patent ID: 6914826
Filing Date: 2005-07-05
Classification: G11C,H01L

Abstract:
1. A method of operating a flash memory device, wherein the flash memory device includes a P-type substrate, an N-type well region within the P-type substrate, a P-well region within the N-well region, a first memory cell and a second memory cell over the P-type substrate wherein the first memory cell has a first control gate and the second memory cell has a second control gate, a select gate between the first memory cell and the second memory cell, a first source/drain region and a second source/drain region in the P-well region on one side of the first memory cell and the second memory cell respectively, and the first source/drain region and the second source/drain region are N-type regions, the method comprising the steps of: programming data into the first memory cell of the flash memory device includes: applying a first positive voltage to the first control gate, applying a first negative voltage to the P-well region, connecting the select gate to ground and setting the first source/drain region and the second source/drain region in a floating state so that F-N tunneling effect is activated to program data into the first memory cell; reading data from the first memory cell of the flash memory device includes: applying a second positive voltage to the select gate, applying the second positive voltage to the first control gate, applying a third positive voltage to the second control gate, applying a fourth positive voltage to the second source/drain region and setting the first source/drain region and the P-well region in a floating state so that data can be read from the first memory cell; and erasing data from the first memory device of the flash memory device, includes: applying a fifth positive voltage to the select gate, setting the first control gate and the second control gate to 0V and setting the first source/drain region and the second source/drain region to a floating state so that F-N tunneling effect is activated to erase data from the flash memory device.