Enhanced reliability for gate dielectric of low-temperature polysilicon thin-film transistors by NO-plasma nitridation

D.C.T. Or1, P.T. Lai1, J.K.O. Sin2, J.P. Xu3
1Department of Electrical and Electronic Engineering, University of Hong Kong, Hong Kong, China
2Department of EIectrical and Electronic Engineering, Hong Kong University of Science and Technology, Hong Kong, China
3Department of Electronic Science & Technology, Huazhong University of Science and Technology, Wuhan, China

Tóm tắt

Polysilicon thin-film transistors (poly-Si TFTs) fabricated solely by low-temperature processes (under 600/spl deg/C) are treated with nitridation using NO plasma. Their properties are investigated at room temperature under high-field stress. It is found that the plasma is effective in improving the gate-oxide hardness against stress-induced damage, with the nitrided device showing a smaller shift in threshold voltage, a smaller decrease in peak transconductance and a smaller increase in subthreshold slope after the stress. This result shows that plasma nitridation has positive effects on the reliability of low-temperature-fabricated poly-Si TFTs, which play an important role nowadays in low-cost flat-panel display systems on glass.

Từ khóa

#Dielectrics #Thin film transistors #Plasma devices #Plasma temperature #Plasma properties #Stress #Plasma displays #Threshold voltage #Transconductance #Glass

Tài liệu tham khảo

maikap, 2000, NO/O2/NO plasma grown oxynitride films on silicon, Proc SPIE, 3975, 411 lee, 1998, Improved stability of short-channel hydrogenated N-channel polycrystalline silicon thin-film transistors with very thin ECR N2O-plasma gate oxide, IEEE Electron Device Lett, 19, 458, 10.1109/55.735745 10.1109/55.400733 10.1109/55.144977 10.1109/T-ED.1987.23226 10.1109/16.554793 khamesra, 0, Device degradation of n-channel poly-Si TFT'sauwht due to high-field, hot-carrier and radiation stressing, Proceedings of the 8thIPFA 2001, 258 david, 2002, Enhanced reliability for low-temperature gate dielectric of MOS devices by N2O or NO plasma nitridation, IEEE Electron Device Lett kato, 1992, Degradation mechanism of polysilicon TFT's under D.C. stress, IEDM Tech Dig, 677