Increasing VG-type 3D NAND flash cell density by using ultra-thin poly-silicon channels
Teng-Hao Yeh, Pei-Ying Penny Du, Tzu‐Hsuan Hsu, Wei-Chen Chen, Hang-Ting Lue, Yen-Hao Shih, Yu-De Huang, Han-Hui Hsu, Lo-Yueh Lin, Ya‐Chin King, Tahone Yang, Chih-Yuan Lu · 2013
Z-direction pitch (stacking period) scaling is critical to the ultimate number of stacking of 3D NAND Flash. In this work, we study the ultra-thin (<;10nm) poly-Si channel together with a thinner inter-poly oxide for Vertical Gate (VG)-type 3D NAND Flash. For the first time, the Z pitch is successfully scaled to 18nm and the memory cell still provides adequate performance. The impact of the Z pitch on the P/E memory window, Z disturb, and read current are studied extensively.