Statistical characterization of vertical poly-Si channel using charge pumping technique for 3D flash memory optimization

Abstract

We analyzed the charge pumping signals in ultra-scaled 3D vertical devices.Statistical analysis has been used to characteristic the variability of poly-Si channel.The quality of bottom and top junctions with different process has been presented.Different poly-Si formations and hole sizes have been investigated.Different annealing conditions have been carried out for optimization of the channel of 3D flash memory. Poly silicon has been used as the vertical channel material in 3D devices for future generations of NAND flash memory. Improving the read current and reducing its variations in the small-sized single-hole structure are among the critical challenges, which require understanding and characterizing interface states and bulk defects in the vertical 3D poly-Si channel. In this paper, we analyzed the charge pumping signals in ultra-scaled 3D vertical devices and characterized the poly-Si channel by using statistical analysis. Devices with different poly-Si formations, hole sizes and annealing conditions have been investigated, in order to optimize the 3D device.