Read only semiconductor memory device with polysilicon drain extensions

摘要

A semiconductor memory device is formed of a polycrystalline silicon electrode terminal layer, which is formed on a MOS transistor except over the gate region and is connected to the drain region of the MOS transistor, and metal wire layer, which is formed on the MOS transistor except over the gate region and is connected to the electrode terminal layer to transmit output signals. Data is written into the semiconductor memory device by ion implantation of the gate of the MOS transistor after the metal wire layer is formed.