Browsing by Author "Chou, Yen-Pang"

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A statistical model for simulating the effect of UPS TFT device variation for SOP applications
(2007-12-01)
Tai, Ya-Hsiang
;
Huang, Shih-Che
;
Chen, Wan-Ping
;
Chao, Yu-Te
;
Chou, Yen-Pang
In this paper, the variation characteristics of low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) are investigated with a statistical approach. A special layout is proposed to investigate the device variation with respect to various devices distances. Two non-Gaussian equations are proposed to fit the device parameter distributions, whose the coefficients of determination (R(2)) are both near 0.9, reflecting the validity of the model. Two benchmark circuits are used to compare the difference between the proposed model and the conventional Gaussian distribution for the device parameter distribution. The output behaviors of the digital and analog circuits show that the variation in the short range would greatly affect the performance of the analog circuits and would instead be averaged in the digital circuits.
Statistical study on the states in the low-temperature poly-silicon films with thin film transistors
(2006-11-25)
Huang, Shih-Che
;
Chou, Yen-Pang
;
Tai, Ya-Hsiang
;
光電工程學系
;
顯示科技研究所
Laser recrystallized low temperature poly-silicon films have attracted attention for their applications in thin-film transistors (TFTs), which are widely used in active matrix displays. The electrical characteristics of the poly-silicon film may vary because of its grain boundaries. In this work, the variation is statistically studied with respect to the threshold voltage and mobility of the TFTs. The threshold voltage and mobility of many closely-located TFTs are measured. These two parameters correspond to the deep states and tail states of the poly-silicon film, respectively. The mutual difference of two threshold voltages exhibits the distribution in a Gaussian-Lorentzian cross product form. On the other hand, the mutual difference of two mobility exhibits the distribution of Lorentzian function. This result directly reflects the local fluctuations and the spatial trends of the deep and tail states in a poly-silicon film. (c) 2006 Elsevier B.V. All rights reserved.