Browsing by Author "Lo, WH"

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A novel process-compatible fluorination technique with electrical characteristic improvements of poly-Si TFTs
(2005-06-01)
Wang, SD
;
Lo, WH
;
Chang, TY
;
Lei, TF
;
電子工程學系及電子研究所
A process-compatible fluorine passivation technique of poly-Si thin-film transistors (TFTs) was demonstrated by employing a novel CF4 plasma treatment. Introducing fluorine atoms into poly-Si films can effectively passivate the trap states near the SiO2/poly-Si interface. With fluorine incorporation, the electrical characteristics of poly-Si TFTs can be significantly improved including a steeper subthreshold slope, smaller threshold voltage, lower leakage current, higher field-effect mobility, and better On/Off current ratio. Furthermore, the CF4 plasma treatment also improves the reliability of poly-Si TFTs with respect to hot-carrier stress, which is due to the formation of strong Si-F bonds.
CF4 plasma treatment for fabricating high-performance and reliable solid-phase-crystallized poly-Si TFTs
(2005)
Wang, SD
;
Lo, WH
;
Lei, TF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A CF4 plasma treatment on solid-phase-crystallized (SPC) poly-Si thin-film transistors ( TFTs ) has been demonstrated. Using this technique, fluorine atoms can be introduced into the poly-Si film to passivate the defects, and hence, the device performance of the SPC poly-Si TFTs can be significantly improved. The fluorinated SPC poly- Si TFTs exhibit a good subthreshold slope, low threshold voltage, and high field effect mobility. Moreover, the fluorinated SPC poly- Si TFTs also exhibit an improved hot-carrier-stress immunity, which is due to the strong Si-F bonds formed in the poly-Si channel region. (c) 2005 The Electrochemical Society.
Drain/gate-voltage-dependent on-current and off-current instabilities in polycrystalline silicon thin-film transistors under electrical stress
(2005-09-01)
Wang, SD
;
Chang, TY
;
Lo, WH
;
Sang, JY
;
Lei, TF
The On-current (I(on)) and Off-current (I(off)) instabilities of polycrystalline silicon thin-film transistors (poly-Si TFTs) were investigated under various stress conditions. The stress-induced device degradation was studied by measuring the dependences Of I(on) and I(off) on the drain/gate voltages. From the results, dissimilar variations in I(on) and I(off) were observed. The differences can be attributed to the variances in the amount of trap charges in the gate oxide and the spatial distributions of the trap states generated in the poly-Si channel. A comprehensive model for the degradation Of I(on) and I(off) in poly-Si TFTs under various electrical stress conditions was suggested.
Mechanism of on-current and off-current instabilities under electrical stress in polycrystalline silicon thin-film transistors
(2005)
De Wang, S
;
Chang, TY
;
Lo, WH
;
Lei, TF
;
電子工程學系及電子研究所
The On-current (I(on)) and Off-current (I(off)) instabilities of polycrystalline silicon thin-film transistors (poly-Si TFTs) were investigated under various electrical stress conditions. The stress-induced device degradation was studied by measuring the dependences of I(on) and I(off) on the drain/gate voltages. Using this technique, dissimilar variations of I(on) and I(off) after stress were observed. The differences can be attributed to the variances in the amount of charges trapped in the gate oxide and the spatial distributions of the trap states generated in the poly-Si channel. These results suggested a comprehensive model for the I(on) and I(off) instabilities of poly-Si TFTs.
Performance and reliability of poly-Si TFTs on FSG buffer layer
(2005-07-01)
De Wang, S
;
Chang, TY
;
Chien, CH
;
Lo, WH
;
Sang, JY
A novel and process-compatible scheme for fabricating poly-Si thin-film transistors (TFTs) on an FSG buffer layer was proposed and demonstrated. Experimental results reveal that remarkably improved device performance and uniformity can be achieved with appropriate fluorine concentration. The poly-Si TFTs fabricated on FSG layers have a higher on-current, a lower leakage current, and a higher field-effect mobility compared with the conventional poly-Si TFTs. Furthermore, the incorporation of fluorine also increased the reliability of poly-Si TFTs against hot carrier stressing, which is attributed to the formation of Si-F bonds.