The Electrical Field Enhancement of Corner Effects on Thin-Film Transistor Nonvolatile Memories

• Main Authors: Lin, Mic-Chen, 林岷臻
• Other Authors: Chao, Tien-Sheng
• Format: Others
• Language: en_US
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/41338917259055392516

碩士 === 國立交通大學 === 電子物理系所 === 99 === For the first time, we propose a special structure to enhance the characteristic of TFT-SONOS memory devices. The memory process is not only simple but also compatible with 3D circuit integration. In this thesis, we investigate the effect of corners along channel width direction on TFT-SONOS memory. The experiments in this study used a local-oxidation of silicon (LOCOS) scheme to fabricate an M-shape in the width direction of TFT-SONOS memory. The programming and erasing operations are performed by the FN tunneling (FN) and Substrate transient hot-hole (STHH) injection, respectively. The improvement of M-shape TFT-SONOS memory is due to the locally electrical field enhancement at corners. On the other hand, the other advantage of this corner structure is the rounded corners improve the “Double Hump” situation. “Double Hump” would be caused by non-uniform charges injection. Different oxidation thickness would make the platform and structure off-set of corners are different. The oxidation thicknesses are 100 nm and 150 nm, respectively. The more oxidation makes the higher structure off-set, but it is not direct related devices performance. We found out not the longer of effective width would depress the improvement of program/ erase speed. The design exhibits superior electrical performance, including faster program/ erase speed, excellent data retention at high temperature, and width dependence. Thus, it has the larger application potential for flash memory market in the future.