Title :
A Novel SONOS Memory With Recessed-Channel Poly-Si TFT via Excimer Laser Crystallization
Author :
Lee, I-Che ; Tsai, Chun-Chien ; Kuo, Hsu-Hang ; Yang, Po-Yu ; Wang, Chao-Lung ; Cheng, Huang-Chung
Author_Institution :
Dept. of Electron. Eng. & the Inst. of Electron., Nat. ChiaoTung Univ., Hsinchu, Taiwan
fDate :
4/1/2012 12:00:00 AM
Abstract :
A silicon-oxide-nitride-oxide-silicon memory with recessed-channel (RC) polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) via excimer laser crystallization (ELC) has been demonstrated to achieve a high mobility of ~ 400 cm2/V · s and a large ON/OFF current ratio of ~ 108. Such a high performance is because the RC poly-Si TFTs possess only one perpendicular grain boundary (GB) in the channel and the corresponding protrusion at this GB. In addition, the proposed devices also exhibited the largest memory window of 2.63 V in 10 ms with respect to 2.37 and 1.31 V for the conventional-ELC and solid-phase-crystallized ones, respectively. Since the silicon grain growth could be artificially controlled, the device-to-device uniformity could be significantly improved. Therefore, such a simple scheme is promising for applications of low-temperature poly-Si TFTs in 3-D ICs and system on panel.
Keywords :
crystallisation; excimer lasers; thin film transistors; SONOS memory; device-to-device uniformity; excimer laser crystallization; perpendicular grain boundary; protrusion; recessed-channel poly-Si TFT; recessed-channel polycrystalline-silicon thin-film transistors; silicon grain growth; silicon-oxide-nitride-oxide-silicon memory; solid-phase-crystallized ones; Lasers; Performance evaluation; SONOS devices; Silicon; Thin film transistors; Excimer-laser crystallization (ELC); lateral grain growth; nonvolatile memory; recessed-channel (RC); thin-film transistor (TFT);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2012.2185479
