DocumentCode :
1533130
Title :
Electrical Degradation and Recovery of Low-Temperature Polycrystalline Silicon Thin-Film Transistors in Polycrystalline Silicon Plasma Process
Author :
Chang, Jiun-Jye ; Chang-Liao, Kuei-Shu ; Wang, Tien-Ko ; Wu, Yung-Chun ; Lin, Kao-Chao ; Chen, Chia-Yu ; Chen, Yu-Mou ; Tseng, Jen-Pei ; Hung, Min-Feng
Author_Institution :
Dept. of Eng. & Syst. Sci., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Volume :
58
Issue :
8
fYear :
2011
Firstpage :
2448
Lastpage :
2455
Abstract :
The plasma-process-induced damage (PPID) of low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) during the etching of the poly-Si film was investigated in this paper. The results reveal the relationship between the device degradation and the PPID during TFT liquid-crystal-display fabrication. This degradation is caused in part by the damage at the edge of the poly-Si film in plasma exposure. The trapped-state densities Ntrap are measured to clarify the relationship between instability and plasma etching damages. The plasma-process condition substantially affects the PPID of the poly-Si etching process. The main mechanism is the generation of charge trapping states at the poly-Si grain boundary in the damaged edge of the TFT channel active region. The electrical recovery from the plasma damage is also studied with various postetching treatments. Hydrogen-base plasma treatment and laser anneal process are revealed to improve the device characteristics due to reduction of charge trapping states.
Keywords :
annealing; elemental semiconductors; etching; plasma materials processing; polymer films; semiconductor thin films; silicon; thin film transistors; TFT liquid-crystal-display fabrication; charge trapping state; device degradation; electrical degradation; electrical recovery; hydrogen-base plasma treatment; instability; laser anneal process; low-temperature polycrystalline silicon thin-film transistor; plasma etching damage; plasma exposure; plasma-process-induced damage; poly-Si film; poly-Si grain boundary; polycrystalline silicon plasma process; trapped-state density; Degradation; Etching; Leakage current; Plasmas; Radio frequency; Thin film transistors; Threshold voltage; Grain-boundary trap state; low-temperature polycrystalline silicon (poly-Si) thin-film transistors (LTPS TFTs); negative-bias temperature instability (NBTI); plasma-process-induced damage (PPID);
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/TED.2011.2153855
Filename :
5783902
Link To Document :
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