Title :
Physical Mechanism of High-Programming-Efficiency Dynamic-Threshold Source-Side Injection in Wrapped-Select-Gate SONOS for nor-Type Flash Memory
Author :
Wang, Kuan-Ti ; Chao, Tien-Sheng ; Chiang, Tsung-Yu ; Wu, Woei-Cherng ; Kuo, Po-Yi ; Wu, Yi-Hong ; Lu, Yu-Lun ; Liao, Chia-Chun ; Yang, Wen-Luh ; Lee, Chien-Hsing ; Hsieh, Tsung-Min ; Liou, Jhyy-Cheng ; Wang, Shen-De ; Chen, Tzu-Ping ; Chen, Chien-Hung ;
Author_Institution :
Dept. of Electrophys., Nat. Chiao Tung Univ., Hsinchu, Taiwan
Abstract :
For the first time, a programming mechanism for conventional source-side injection (SSI) (normal mode), substrate-bias enhanced SSI (body mode), and dynamic-threshold SSI (DTSSI) (DT mode) of a wrapped-select-gate SONOS memory is developed with 2-D Poisson equation and hot-electron simulation and programming characteristic measurement for NOR flash memory. Compared with traditional SSI, DTSSI mechanisms are determined in terms of lateral acceleration electric field and programming current (IPGM) in the neutral gap region, resulting in high programming efficiency. Furthermore, the lateral electric field intersects the vertical electric field, indicating that the main charge injection point is from the end edge of the gap region close to the word gate.
Keywords :
NOR circuits; Poisson equation; field effect memory circuits; flash memories; hot carriers; logic gates; 2D Poisson equation; NOR-type flash memory; conventional source-side injection; dynamic-threshold SSI; dynamic-threshold source-side injection; high programming efficiency; hot-electron simulation; lateral acceleration electric field; neutral gap region; programming characteristic measurement; programming current; substrate-bias enhanced SSI; wrapped-select-gate SONOS memory; Memory; programming mechanism; wrapped-select-gate SONOS (WSG SONOS);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2009.2031601
