Browsing by Author "Yeh (Huang), Fon-Shan"

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Formation and nonvolatile memory characteristics of W nanocrystals by in-situ steam generation oxidation
(2010-12-30)
Chen, Shih-Cheng
;
Chang, Ting-Chang
;
Hsieh, Chieh-Ming
;
Li, Hung-Wei
;
Sze, S. M.
The authors provide the formation and memory effects of W nanocrystals nonvolatile memory in this study. The charge trapping layer of stacked a-Si and WSi(2) was deposited by low pressure chemical vapor deposition (LPCVD) and was oxidized by in-situ steam generation system to form uniform W nanocrystals embedded in SiO(2). Transmission electron microscopy analyses revealed the microstructure in the thin film and X-ray photon-emission spectra indicated the variation of chemical composition under different oxidizing conditions. Electrical measurement analyses showed the different charge storage effects because the different oxidizing conditions influence composition of trapping layer and surrounding oxide quality. Moreover, the data retention and endurance characteristics of the formed W nanocrystal memory devices were compared and studied. The results show that the reliability of the structure with 2% hydrogen and 98% oxygen at 950 degrees C oxidizing condition has the best performance among the samples. (C) 2010 Elsevier B.V. All rights reserved.
Influence of hydrogen plasma treatment on charge storage characteristics in high density tungsten nanocrystal nonvolatile memory
(2011-03-31)
Chen, Shih-Cheng
;
Chang, Ting-Chang
;
Chen, Wei-Ren
;
Lo, Yuan-Chun
;
Wu, Kai-Ting
This study focuses on the influence of a hydrogen plasma treatment on electrical properties of tungsten nanocrystal nonvolatile memory. The X-ray photon emission spectra show that, after the hydrogen plasma treatment, a change in binding energy occurs such that Si(x+) and Si(y+) peaks appear at a position that is shifted about 2.3 and 3.3 eV from Si(o+) in Si 2p spectra. This indicates that Si dangling bonds are passivated to form a Si-H bond structure in the SiO(2). Furthermore, the transmission electron microscopy shows cross-sectional and plane-view for the nanocrystal microstructure after the hydrogen plasma treatment. Electrical measurement analyses show improved data retention because the hydrogen plasma treatment enhances the quality of the oxide surrounding the nanocrystals. The endurance and retention properties of the memory device are improved by about 36% and 30%, respectively. (C) 2011 Elsevier By. All rights reserved.
Influence of Oxygen Partial Pressure on Resistance Random Access Memory Characteristics of Indium Gallium Zinc Oxide
(2011)
Chen, Min-Chen
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Chang, Ting-Chang
;
Huang, Sheng-Yao
;
Chang, Guan-Chang
;
Chen, Shih-Cheng
This paper investigates the effect of oxygen concentrations of InGaZnO films on the resistive switching characteristics of a Pt/InGaZnO (IGZO)/TiN structure. The IGZO films were prepared by an RF magnetron sputtering system at various oxygen partial pressures at room temperature. The memory devices reveal a reversible unipolar switching behavior. In addition, the high-resistance state current was found to be strongly dependent on oxygen concentration. X-ray photoelectron spectroscopy analyses attributed this phenomenon to the non-lattice oxygen concentration in the IGZO thin films, rather than the change in crystalline constituent. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.007112esl] All rights reserved.
Surface states related the bias stability of amorphous In-Ga-Zn-O thin film transistors under different ambient gasses
(2011-12-30)
Chen, Yu-Chun
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chen, Shih-Cheng
;
Chung, Wan-Fang
This paper investigates the origin of the bias stability under ambient gas (oxygen, moisture and vacuum) of In-Ga-Zn-O thin film transistors with different annealing temperatures. In Zn-based TFTs, the electrical characteristic of device is a strongly function with the ambient gas, the simultaneous gas ambient and bias stresses are applied on devices annealed in atmosphere ambient to study this issue. The result shows the device which is annealed at temperature up to 330 degrees C has worst reliability. We suppose that the sensitivity of gas ambient depend the defect state, which is associated to the annealing temperature, of surface in a-IGZO. (C) 2011 Elsevier B.V. All rights reserved.