Browsing by Author "Chang, MC"

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A new simulation model for plasma ashing process-induced oxide degradation in MOSFET
(1998-01-01)
You, KF
;
Chang, MC
;
Wu, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Plasma ashing process-induced oxide damage is studied quantitatively in this paper, To simulate thin gate-oxide damage due to plasma ashing process, a new equivalent circuit model is proposed by including a differential capacitance, a parasitic resistance, an offset flatband voltage, and the effects of feedback on the interface-state and trapped oxide charge densities generated during plasma ashing process, According to this new model, computation of gate oxide charging current is performed by correlating to the latent interface-state density, The test n-MOSFET devices including different antenna-ratios are measured, and excellent agreement is obtained as compared with measured results, Moreover, the deficiency of the previous model is stated and compared, In addition, the effects of substrate doping concentration on plasma-induced oxide damage are also investigated as well as those of plasma ion density, plasma uniformity, thin gate-oxide thickness, Therefore, the relationships between interface state/oxide traps and antenna ratio are linked to provide a guideline for circuit designers and the plasma ashing process-induced damage can be predicted.
A physical model for hole direct tunneling current in P+ poly-gate PMOSFETs with ultrathin gate oxides
(2000-11-01)
Yang, KN
;
Huang, HT
;
Chang, MC
;
Chu, CM
;
Chen, YS
A model of the hole direct tunneling gate current accounting for heavy and light hole's subbands in the quantized inversion layer is built explicitly. This model comprises four key physical parameters: inversion layer charge density, hole impact frequency on SiO2/Si interface, WKB transmission probability, and reflection correction factor. With the effective hole mass m(oxh) = 0.5m(o) for parabolic dispersion relationship in the oxide, experimental reproduction without any parameter adjustment is consistently achieved in p(+) poly-gate pMOSFETs with 1.23, 1.85, and 2.16 nm gate oxide thicknesses. The proposed model can thereby serve as a promising characterization means of direct tunnel oxides. In particular, it is calculated that the secondary subbands and beyond, although occupying few holes, indeed contribute substantially to the direct tunneling conduction due to effective lo,vcr barrier heights, and are prevailing over the first subbands for reducing oxide field down below 1 MV/cm.
Characterization of BaPbO3 and Ba(Pb1-xBix)O-3 thin films
(2002-02-17)
Sun, CL
;
Wang, HW
;
Chang, MC
;
Lin, MS
;
Chen, SY
BaPbO3 and Ba(Pb1-xBix)O-3 films made from barium 2-ethylhexanoate, lead 2-ethylhexanoate and bismuth acetate were prepared by metal-organic deposition (MOD) method on Pt/Ti/SiO2/Si substrate. The phase transition and the physical properties of these films were studied. The polycrystalline BaPbO3 phase starts to form above 600 degreesC and the Pb-excess addition would enhance the formation of single perovskite BaPbO3 phase. With increasing annealing temperature, the optimum sheet resistance 1.6 Omega sq(-1) (resistivity approximate to 1.07 x 10(-4) Omega cm) could be obtained at 750 degreesC. However, an annealing temperature over 800 degreesC causes reactions between substrate and BaPbO3 phase and results in sharp increase of resistance. On the other hand, the substitution of Pb by Bi in the Ba(Pb1-xBix)O-3 films could stabilize the perovskite phase, though the sheet resistance is raised over 10 Omega sq(-1) at x = 0.3. (C) 2002 Elsevier Science B.V. All rights reserved.
Characterization of BaPbO3 and Ba(Pb1-xBix)O-3 thin films
(2003-02-17)
Sun, CL
;
Wang, HW
;
Chang, MC
;
Lin, MS
;
Chen, SY
BaPbO3 and Ba(Pb1-xBix)O-3 films made from barium 2-ethylhexanoate, lead 2-ethylhexanoate and bismuth acetate were prepared by metal-organic deposition (MOD) method on Pt/Ti/SiO2/Si substrate. The phase transition and the physical properties of these films were studied. The polycrystalline BaPbO3 phase starts to form above 600 degreesC and the Pb-excess addition would enhance the formation of single perovskite BaPbO3 phase. With increasing annealing temperature, the optimum sheet resistance 1.6 Omega sq(-1) (resistivity approximate to 1.07 x 10(-4) Omega cm) could be obtained at 750 degreesC. However, an annealing temperature over 800 degreesC causes reactions between substrate and BaPbO3 phase and results in sharp increase of resistance. On the other hand, the substitution of Pb by Bi in the Ba(Pb1-xBix)O-3 films could stabilize the perovskite phase, though the sheet resistance is raised over 10 Omega sq(-1) at x = 0.3. (C) 2002 Elsevier Science B.V. All rights reserved.
Reaction kinetics and mechanism of BaPbO3 formation
(2000-06-15)
Chang, MC
;
Wu, JM
;
Cheng, SY
;
Chen, SY
;
材料科學與工程學系
The influence of starting materials on the formation of BaPbO3 is studied. The reaction kinetics of perovskite BaPbO3 phase formation depends greatly on the phase of lead oxide raw materials. Kinetics of BaPbO3 formation is analyzed by the Johnson-Mehl-Avrami model. The experimental results reveals that the reaction of BaCO3-PbO2 raw materials has a reaction order of n = 5/2, and the reaction is controlled by diffusion. On the other hand, in the case of BaCO3-PbO system, the reaction order n is equal to 1. The formation is controlled by the interface reaction. In the final stage of both systems, the reaction orders are the same of about 0.5. The phases left in the final stage are BaPbO3 and BaCO3. (C) 2000 Elsevier Science S.A. All rights reserved.
Resonant optical nonlinearity of conjugated polymers
(1997-11-15)
Chang, MC
;
Meng, HF
;
物理研究所
;
Institute of Physics
When the energy of a pump wave is in resonance with the exciton creation energy, the electric susceptibility of a conjugated polymer in response to the probe wave is altered by the exciton gas. In this paper we calculate the dependence of this change on the exciton populations by the equation of motion (EOM) method. The magnitude of optical nonlinearity is also influenced by ambient temperature, by the extent of exciton wave functions, and by the strength of electron-electron interaction. All of these factors can be easily incorporated in the EOM approach systematically. Using the material parameters for polydiacetylene, the optical Ken coefficient n(2) obtained is about 10(-8) cm(2)/W, which is close to experimental value, and is four orders of magnitude larger than the value in nonresonant pump experiments.
Resonant optical nonlinearity of conjugated polymers
(1997-11-15)
Chang, MC
;
Meng, HF
;
物理研究所
;
Institute of Physics
When the energy of a pump wave is in resonance with the exciton creation energy, the electric susceptibility of a conjugated polymer in response to the probe wave is altered by the exciton gas. In this paper we calculate the dependence of this change on the exciton populations by the equation of motion (EOM) method. The magnitude of optical nonlinearity is also influenced by ambient temperature, by the extent of exciton wave functions, and by the strength of electron-electron interaction. All of these factors can be easily incorporated in the EOM approach systematically. Using the material parameters for polydiacetylene, the optical Ken coefficient n(2) obtained is about 10(-8) cm(2)/W, which is close to experimental value, and is four orders of magnitude larger than the value in nonresonant pump experiments.
The effect of ball-milling solvent on the decomposition properties of Ba(Pb1-xBix)O-3
(2001-03-01)
Chang, MC
;
Wu, JM
;
Cheng, SY
;
Chen, SY
;
材料科學與工程學系
Ba(Pb1-xBix)O-3 compound, which exhibits perovskite structure is a superconducting material. It can be a useful material for resistor when x value equals 0. The conducting behavior of BaPbO3 is liable to be affected during aqueous processing. In contrast, the phenomenon is not found in Ba(Pb0.8Bi0.2)O-3 The milling solvents of water and ethanol have different effect on the stability of perovskite phase. The decomposition of BaPbO3 into BaCO3 and PbO2 is found when CO32- ion exists. The partial substitution of Bi3+ stabilizes the perovskite phase. The stabilization and decomposition of perovskite phase explain the resistivity change with different milling solvents. (C) 2001 Elsevier Science B.V. All rights reserved.