Mechanical Stress Distribution and the Effects of Process Parameter Changes in Vertical NAND Flash Memory
Yeon Namkoong, Hyung Jun Yang, Yun Heub Song · Journal of Nanoscience and Nanotechnology · 2017
We investigated the stress distribution and electrical characteristics according to changes in the process parameters in a vertical NAND (VNAND) flash cell with a poly-Si channel. We used technology computer-aided design to confirm that process parameters changes affect the stress distribution in a VNAND flash cell and the stress in the poly-Si channel. Also, we found that, as the stress distributions changed, the electrical characteristics depended significantly on the annealing temperature, channel hole angle, and tungsten intrinsic stress in a VNAND flash cell. Thus, the industry needs to develop and apply better process parameters and acquire a better understanding of how the electrical characteristics of a VNAND flash cell depend on those parameters.