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

Volume

33

Issue

4

fYear

2012

fDate

4/1/2012 12:00:00 AM

Firstpage

558

Lastpage

560

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);

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2012.2185479

Filename

6163340