Impact of critical geometry dimension on channel boosting potential in 3D NAND memory
Dandan Jiang, Zhiliang Xia, Lei Jin, Yu Zhang, Xingqi Zou, Peizhen Hong, Qiang Xu, Zhaoyun Tang, Jing Gao, Ming Zeng, Shaoning Mei, Zongliang Huo · 2016
The impact of polysilicon thickness (THK-poly) and channel hole diameter (CHCD) on channel boosting potential during program inhibit has been studied with Sentaurus device simulator for three dimensional (3D) NAND memory. According to the distribution of boosting potential along the channel, the potential level of thinner THK-poly is higher than that of thicker one. Moreover, the correlation between boosting potential and CHCD also depends on the THK-poly. In the case of 20nm THK-poly, strong dependence between potential and CHCD is observed. When the THK-poly decreases to 5nm, boosting potential is almost independent with the CHCD. Our results provide guidance for predicting and optimizing the program disturbance characteristic for highly reliable 3D NAND flash memory.