DocumentCode :
837668
Title :
A Novel Self-Aligned Etch-Stopper Structure With Lower Photo Leakage for AMLCD and Sensor Applications
Author :
Liang, Chung-Yu ; Gan, Feng-Yuan ; Liu, Po-Tsun ; Yeh, F.S. ; Chen, Stephen Hsin-Li ; Chang, Ting-Chang
Author_Institution :
Inst. of Electron. Eng., Nat. Tsing Hua Univ., Hsinchu
Volume :
27
Issue :
12
fYear :
2006
Firstpage :
978
Lastpage :
980
Abstract :
In this letter, the authors introduce a novel self-aligned etch-stopper sidewall-contact hydrogenated amorphous silicon (a-Si : H) thin-film transistor (ESSC-TFT), which reduces the photo leakage current by more than one order of magnitude and increases the on-off ratio to seven orders of magnitude under back light illumination. Such a TFT will enable high-resolution and high-brightness liquid-crystal displays (LCDs) for next-generation TV, monitor, notebook, and mobile-phone applications. This ESSC-TFT design reduces the volume of a-Si film in which the active region can totally be shielded by the gate metal resulting in the prevention from direct back light illumination. With the sidewall contact, the hole current is reduced due to the smaller contact area between drain/source and a-Si layer. As well as the source, drain parasitic intrinsic resistance of a-Si can be also lessened by the ESSC-TFT structure. Although the defects between etched a-Si and n+ a-Si film may degrade the on current, the ESSC-TFT still exhibits higher on-off ratio and lower leakage than the one in traditional etch-stopper (ES)-TFT structure. The ESSC-TFT structure can be used not only for TFT-LCD application but also for the applications that demand high on-off ratio and low-leakage device, such as X-ray image sensor
Keywords :
amorphous semiconductors; leakage currents; liquid crystal displays; sensors; silicon; thin film transistors; AMLCD; direct back light illumination; drain parasitic intrinsic resistance; hole current; liquid-crystal displays; photo leakage current; self-aligned etch-stopper structure; sensor applications; sidewall contact; sidewall-contact hydrogenated amorphous silicon thin-film transistor; Active matrix liquid crystal displays; Amorphous silicon; Degradation; Etching; Leakage current; Lighting; Liquid crystal displays; Monitoring; TV; Thin film transistors; Hydrogenated amorphous silicon; light-shield; parasitic resistance; self-aligned; thin-film transistor (TFT);
fLanguage :
English
Journal_Title :
Electron Device Letters, IEEE
Publisher :
ieee
ISSN :
0741-3106
Type :
jour
DOI :
10.1109/LED.2006.886418
Filename :
4016192
Link To Document :
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