Title :
Vertical-channel stacked array (VCSTAR) for 3D NAND flash memory
Author :
Kim, Yoon ; Park, Se Hwan ; Kim, Wandong ; Seo, Joo Yon ; Park, Byung-Gook
Author_Institution :
Inter-Univ. Semicond. Res. Center (ISRC), Seoul Nat. Univ., Seoul, South Korea
Abstract :
Recently, 3D stacked NAND flash architectures have been proposed to solve scaling limit of the planar NAND flash memory based on floating-gate type [1]-[2]. However, theses structures have several drawbacks. For TCAT[1], declined hole-etch slope leads to different curvature radius of each stacked active layers. Consequently, different electric field is applied to each layer in program operation, which causes the threshold voltage distribution problem. In case of VSAT[2], it is almost impossible to implement metal gate structure. Also, VSAT has the limitation of the stacking extendability due to inefficient bit line current flow (going up and down).
Keywords :
NAND circuits; flash memories; 3D NAND flash memory; 3D stacked NAND flash architectures; TCAT; VCSTAR; VSAT; bit line current flow; curvature radius; declined hole-etch slope; electric field; floating-gate type; metal gate structure; planar NAND flash memory; program operation; stacked active layers; stacking extendability; threshold voltage distribution problem; vertical-channel stacked array; Arrays; Doping; Flash memory; Logic gates; Stacking; Three dimensional displays;
Conference_Titel :
Semiconductor Device Research Symposium (ISDRS), 2011 International
Conference_Location :
College Park, MD
Print_ISBN :
978-1-4577-1755-0
DOI :
10.1109/ISDRS.2011.6135406