Nonvolatile semiconductor memory and method of driving the same

Abstract

It is an object of the present invention to provide a nonvolatile semiconductor memory including memory cells using side walls of island semiconductor layers which avoid lowing of the writing speed and the reading speed. In the nonvolatile semiconductor memory having the nonvolatile semiconductor memory cells each having an island semiconductor layer formed on a semiconductor substrate, the island semiconductor layer having a drain diffusing layer formed on top thereof, a source diffusion layer formed on the lower side thereof, a charge-storage layer formed on a channel area on the side wall interposed between the drain diffusion layer and the source diffusion layer via a gate insulation film, and a control gate formed on the charge-storage layer arranged in matrix, bit lines connected to the drain diffusion layers are arranged in the column direction, control gate lines are arranged in the row direction, and source lines connected to the source diffusion layers are arranged in the column direction, the above-described object is achieved by the nonvolatile semiconductor memory characterized in that common source lines connected to the source lines are formed at every predetermined number of control gate lines, the common source lines are formed of metal, and the common source lines are arranged in the row direction.