Browsing by Author "Wang, Mu-Chun"

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Gate-to-drain capacitance verifying the continuous-wave green laser crystallization n-TFT trapped charges distribution under dc voltage stress
(2009-12-21)
Hsieh, Zhen-Ying
;
Wang, Mu-Chun
;
Chen, Shuang-Yuan
;
Chen, Chih
;
Huang, Heng-Sheng
In this work, a metrology was proposed to realize the distribution of fixed oxide trapped charges and grain boundary trapped states. The (continuous-wave green laser crystallization) n-channel thin-film transistors (TFTs) were forced by dc voltage stress, V(G)=V(D). The gate-to-drain capacitance, C(GD) -V(G), with varying frequency of applied small signal was developed. To probe the distribution of these defects, the difference (initial capacitance values minus stressed capacitance values) of C(GD) -V(G) with different frequencies was precisely studied. (C) 2009 American Institute of Physics. [doi:10.1063/1.3275728]
On the Nitrogen Doping in Erbium and Nitrogen Codoped Magnesium Zinc Oxide Diode by Spray Pyrolysis
(2020-01-01)
Chen, Chun-An
;
Hsu, Yu-Ting
;
Lan, Wen-How
;
Huang, Kai-Feng
;
Chang, Kuo-Jen
Diodes with an erbium and nitrogen codoped magnesium zinc oxide (MgZnO:Er,N) active layer were fabricated by spray pyrolysis on Si substrate with aqueous solutions including magnesium nitrate, zinc acetate, erbium acetate, ammonium acetate, and indium nitrate precursors. Diodes with different nitrogen content in their precursor were prepared and their properties were investigated. With scanning electron microscopy, film surface with mixed hexagonal flakes and tiny blocks was characterized for all samples. Certain morphologies varied for samples with different N contents. In the photoluminescence analyses, the intensity of the oxygen-related defects peak increased with the increasing of nitrogen content. The diodes were fabricated with an Au and In deposition on the top and backside. The diode current-voltage as well as capacitance-voltage characteristics were examined. An ununiformed n-type concentration distribution with high concentration near the interface in the MgZnO:Er,N layer was characterized for all samples. Diodes with high nitrogen content exhibit reduced breakdown voltage and higher interface concentration characteristics. Under reversed bias conditions with an injection current of 50 mA, a light spectrum with two distinct green emissions around wavelengths 532 and 553 nm was observed. A small spectrum variation was characterized for diodes prepared from different nitrogen content. The diode luminescence characteristics were examined and the diode prepared from N/Zn=1 in the precursor showed an optimal injection current-to-luminescence property. The current and luminescence properties of the diode were characterized and discussed.
Thickness Study of Er-Doped Magnesium Zinc Oxide Diode by Spray Pyrolysis
(2018-12-01)
Hsu, Yu-Ting
;
Lee, Che-Chi
;
Lan, Wen-How
;
Huang, Kai-Feng
;
Chang, Kuo-Jen
Erbium-doped magnesium zinc oxides were prepared through spray pyrolysis deposition at 450 degrees C with an aqueous solution containing magnesium nitrate, zinc acetate, erbium acetate, and indium nitrate precursors. Diodes with different erbium-doped magnesium zinc oxide thicknesses were fabricated. The effect of erbium-doped magnesium zinc oxide was investigated. The crystalline structure and surface morphology were analyzed using X-ray diffraction and scanning electron microscopy. The films exhibited a zinc oxide structure, with (002), (101), and (102) planes and tiny rods in a mixed hexagonal flakes surface morphology. With the photoluminescence analyses, defect states were identified. The diodes were fabricated via a metallization process in which the top contact was Au and the bottom contact was In. The current-voltage characteristics of these diodes were characterized. The structure resistance increased with the increase in erbium-doped magnesium zinc oxide thickness. With a reverse bias in excess of 8 V, the light spectrum, with two distinct green light emissions at wavelengths of 532 nm and 553 nm, was observed. The light intensity that resulted when using a different operation current of the diodes was investigated. The diode with an erbium-doped magnesium zinc oxide thickness of 230 nm shows high light intensity with an operational current of 80 mA. The emission spectrum with different injection currents for the diodes was characterized and the mechanism is discussed.
Trend transformation of drain-current degradation under drain-avalanche hot-carrier stress for CLC n-TFTs
(2009-08-01)
Hsieh, Zhen-Ying
;
Wang, Mu-Chun
;
Chen, Chih
;
Shieh, Jia-Min
;
Lin, Yu-Ting
Continuous-wave green laser-crystallized (CLC) single-grain-like polycrystalline silicon n-channel thin-film transistors (poly-Si n-TFTs) demonstrate the higher electron mobility and turn-on current than excimer laser annealing (ELA) poly-Si n-TFTs. Furthermore, high drain voltage accelerates the flowing electrons in n-type channel, and hence the hot-carriers possibly cause a serious damage near the drain region and deteriorate the source/drain (S/D) current. in this study, at high drain stress voltage, it appears that CLC TFT was degraded in the initial stress time (before 50 s), but the drain current was enhanced after 50 s. After 50 s stress time, the amount of grain boundary trap states near the drain side was getting large and the reflowing holes damaged the source region or injected into gate oxide near source side as well. (C) 2009 Elsevier Ltd. All rights reserved.