Silicon nitride read only memory structure and method of programming and erasure

摘要

A silicon nitride read only memory and associated method of data programming and erasing. The read only memory includes a first type ion-doped semiconductor substrate, an oxide-nitride-oxide (ONO) composite layer over the semiconductor substrate, a first type ion-doped gate conductive layer over the ONO layer and a second type ion doped source/drain region in the substrate on each side of the ONO layer, wherein the second type ions have an electrical polarity opposite to the first type ions. Data is programmed into the silicon nitride read only memory by channel hot electron injection and data is erased from the silicon nitride read only memory by negative gate channel erase method. Since the gate conductive layer and the channel layer are identically doped, the energy gap between the two layers reduced. Hence, operating voltage of the gate terminal is lowered and damage to the tunnel oxide layer by hot holes is reduced.