Browsing by Author "Wang, FS"

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An adaptive and robust watermarking method based on VQ
(2002-04-01)
Huang, HC
;
Wang, FS
;
Pan, JS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
An adaptive and robust watermarking algorithm based on vector quantization (VQ) is presented in this paper. A binary watermark is adaptively embedded with the characteristics of the original source in the VQ domain, then the watermarked image along with a secret key are transmitted to the receiver for protecting the ownership. In extracting the watermark, we make use of the pre-registered secret key in addition to the watermarked image to examine whether the watermark could survive the intentional attacks or not. We performed a variety of attacks on the watermarked image, including the destruction attacks and the synchronization attacks, to show the robustness and effectiveness of the proposed algorithm. After watermark extraction, we acquired the extracted watermark that is highly similar to the embedded one; in addition, the information conveyed therein is easily recognizable. Hence, the proposed algorithm is not only robust bust also useful for protecting the ownership of digital media.
Effects of NH3 plasma passivation on N-channel polycrystalline silicon thin-film transistors
(1997-01-01)
Cheng, HC
;
Wang, FS
;
Huang, CY
;
奈米中心
;
Nano Facility Center
The NH3-plasma passivation has been performed on polycrystalline silicon (poly-Si) thin-film transistors (TFT's). It is found that the TFT's after the NH3-plasma passivation achieve better device performance, including the off-current below 0.1 pA/mu m and the on/off current ratio higher than 10(8), and also better hot-carrier reliability than the H-2-plasma ones. Based on optical emission spectroscopy (OES) and secondary ion mass spectroscopy (SIMS) analysis, these improvements were attributed to not only the hydrogen passivation of the defect states, but also the nitrogen pile-up at SiO2/poly-Si interface and the strong Si-N bond formation to terminate the dangling bonds at the grain boundaries of the polysilicon films. Furthermore, the gate-oxide leakage current significantly decreases and the oxide breakdown voltage slightly increases after applying NH3-plasma treatment. This novel process is of potential use for the fabrication of TFT/LCD's and TFT/SRAM's.
Effects of NH3 plasma passivation on N-channel polycrystalline silicon thin-film transistors
(1997-01-01)
Cheng, HC
;
Wang, FS
;
Huang, CY
;
奈米中心
;
Nano Facility Center
The NH3-plasma passivation has been performed on polycrystalline silicon (poly-Si) thin-film transistors (TFT's). It is found that the TFT's after the NH3-plasma passivation achieve better device performance, including the off-current below 0.1 pA/mu m and the on/off current ratio higher than 10(8), and also better hot-carrier reliability than the H-2-plasma ones. Based on optical emission spectroscopy (OES) and secondary ion mass spectroscopy (SIMS) analysis, these improvements were attributed to not only the hydrogen passivation of the defect states, but also the nitrogen pile-up at SiO2/poly-Si interface and the strong Si-N bond formation to terminate the dangling bonds at the grain boundaries of the polysilicon films. Furthermore, the gate-oxide leakage current significantly decreases and the oxide breakdown voltage slightly increases after applying NH3-plasma treatment. This novel process is of potential use for the fabrication of TFT/LCD's and TFT/SRAM's.
Investigation of the dosage effect on the activation of arsenic- and boron-implanted low-pressure chemical vapor deposition (LPCVD) amorphous-silicon films
(1996-02-01)
Wang, FS
;
Tsai, MJ
;
Lai, WK
;
Cheng, HC
;
電子工程學系及電子研究所
The dopant activation of arsenic- and boron-implanted low-pressure chemical vapor deposition (LPCVD) amorphous silicon (cu-Si) films, furnace-annealed with different annealing temperatures has been investigated. For the arsenic-implanted specimens with a dosage of 4 x 10(14) cm(-2), an increase of sheet resistance was observed with increasing annealing temperature for the temperatures range from 700 to 850 degrees C. The reverse annealing phenomenon is attributed to dopant segregation at grain boundaries and becomes less marked with heavier doped films (2 x 10(15) cm(-2)). Consequently for a dosage of 1 x 10(16) cm(-2), the sheet resistance exhibits a monotonic decrease with increasing annealing temperature. As for the boron-implanted specimens, the reverse annealing phenomenon is not observed. It means that dopant segregation is not significant for boron-implanted films.
Novel N2O plasma passivation on polycrystalline silicon thin-film transistors
(1997)
Wang, FS
;
Huang, CY
;
Cheng, HC
;
交大名義發表
;
奈米中心
A novel defect passivation process of polycrystalline silicon thin-film transistors (poly-Si TFT's) utilizing nitrous oxide (N2O) plasma was investigated. In terms of the gas flow rate, chamber pressure, and plasma exposure time, the optimum plasma condition has been found to significantly improve the electrical characteristics of poly-Si TFTs. The performance is even better than those passivated with conventional hydrogen plasma. It is believed that the nitrogen radicals from the N2O gas as well as the hydrogen ones from the residual H2O both can diffuse into the gate-oxide/poly-Si interface and the channel poly-Si layer to passivate the defect-states. Furthermore, the gate-oxide leakage current significantly decreases and the oxide breakdown voltage slightly increases after applying N2O-plasma treatment. This novel process is promising for the applications of TFT/liquid crystal displays and TFT/static random access memories.
Plasma passivation effects on polycrystalline silicon thin-film transistors utilizing nitrous oxide plasma
(1997-04-01)
Wang, FS
;
Huang, CY
;
Cheng, HC
;
電子工程學系及電子研究所
;
奈米中心
A novel defect passivation process in polycrystalline silicon (poly-Si) thin-him transistors (TFTs) utilizing nitrous oxide (N2O) plasma has been performed to significantly improve the electrical characteristics of poly-Si TFTs, For example, the on/off current ratio increased to 6.58x10(6); the threshold voltage decreased to 0.55V, and a the field effect mobility increased to 48.2 cm(2)/Vs. The distribution of N incorporated in this oxide and these poly-Si films was examined by means of secoudary ion mass spectroscopy (SIMS) and Auger-electron spectroscopy (AES). It is believed that the nitrogen radicals which dissociated from the N2O gas as well as the hydrogen radicals with dissociated from the residual H2O can both diffuse into the active poly-Si layer to passivate the grain-boundary defect states and accumulate at the gale SiO2/poly-Si interlace lo reduce the interface state density. Thus, the hot-carrier reliability of TFTs M-as also enhanced after the N2O plasma treatments.
Thin-film transistors with polycrystalline silicon films prepared by two-step rapid thermal annealing
(2000-01-15)
Cheng, HC
;
Huang, CY
;
Wang, FS
;
Lin, KH
;
Tarntair, FG
A novel two-step rapid thermal annealing (RTA) process has been developed to significantly reduce the crystallization time for the solid-phase crystallization (SPC) of amorphous silicon films. In comparison with the conventional SPC processes, it not only keeps a low thermal budget but also achieves a larger poly-Si film grain size than that obtained by one-step RTA, and even as large as that obtained by conventional furnace annealing (CFA). Furthermore, poly-Si thin-film transistors fabricated by such a novel annealing scheme possess electrical characteristics superior to those obtained by one-step RTA and comparable to those obtained by long-time CFA.