채널 길이와 도핑 농도에 따른 낸드 플래시 메모리 소자의 결합비 의존성 연구

In the programming operation of the NAND-type flash memory array, the program-inhibited cell is biased with positive voltages on the source and drain junction while program voltage is applied on the control gate, which is called as self-boosting channel program inhibition. As the device is scaled down and the channel doping concentration is varied accordingly, the coupling ratio which is the crucial factor in self-boosting mechanism is also changed. In this work, the dependence of coupling ratio on the channel length and doping concentration is investigated by the numerical device simulation.