Patent ID: 7009888
Filing Date: 2006-03-07
Classification: G09G,G11C,H01L

Abstract:
1. A method for driving a nonvolatile memory device comprising a semiconductor substrate, at least one island semiconductor layer provided on the semiconductor substrate, at least one memory cell having a control gate and a charge storage layer partly or entirely surrounding a peripheral surface of the island semiconductor layer, a first selection transistor provided between the memory cell and the semiconductor substrate and having a first insulation layer and a first selection gate, a source diffusion layer provided as a source between the semiconductor substrate and the island semiconductor layer provided with the memory cell and the first selection transistor for electrically isolating the island semiconductor layer from the semiconductor substrate, a drain diffusion layer provided as a drain in an end surface of the island semiconductor layer opposite from the source diffusion layer with respect to the memory cell, and a second selection transistor provided between the memory cell and the drain diffusion layer and having a second insulation layer and a second selection gate, the method comprising the steps of: applying a negative first voltage to the drain and the first selection gate, applying a positive second voltage to the second selection gate, and applying 0V or a positive third voltage to the source; and applying a positive fourth voltage higher than the second voltage to the control gate of the memory cell, whereby electric charges are injected into the charge storage layer.