NONVOLATILE SEMICONDUCTOR MEMORY AND ITS DRIVE METHOD

摘要

It is possible to provide a nonvolatile semiconductor memory formed by memory cells using the side wall of an island-shaped semiconductor layer capable of evading lowering of write speed and read speed. The nonvolatile semiconductor memory includes an island-shaped semiconductor layer formed on a semiconductor substrate. The island-shaped semiconductor layer is formed by nonvolatile semiconductor memory cells, each having a drain diffusion layer formed on the semiconductor layer, a source diffusion layer formed under the semiconductor layer, a charge accumulation layer formed via a gate insulating film on the channel region of the side wall sandwiched by the drain diffusion layer and the source diffusion layer, and a control gate formed on the charge accumulation layer. The memory cells are arranged in a matrix. Bit lines connected to the drain diffusion layer are arranged in the column direction. Control gate lines are arranged in the row direction. Source lines connected to the source diffusion layer are arranged in the column direction. Common source lines connected to the source lines are formed for each predetermined number of control gate lines. The common source lines are formed by metal and arranged in the row direction.