SEMICONDUCTOR MEMORY DEVICE AND ITS MANUFACTURING METHOD

摘要

PURPOSE: To provide a semiconductor memory device for improving integration degree by reducing the influence of reverse bias effect of the memory device which has a charge storage layer and a control gate, further increasing the ratio of the volumes of a floating gate to the control gate, without increasing an occupying area and suppressing an unevenness of cell characteristics due to a manufacturing process, and to provide a method for manufacturing the same. CONSTITUTION: The semiconductor memory device comprises a semiconductor substrate and at least one memory cell having at least one island-like semiconductor layer; a charge storage layer formed on the entire or a partial periphery of the sidewall of the semiconductor layer and a control gate. In this memory device, at least one of the cells is electrically insulated from the substrate.