An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from...An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from 1 kHz to1 MHz.The proposed model is based on the Fermi-Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal.The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data.Simulations indicate thatthe capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface,with negligible effects from the traps far from the interface,and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed.In addition,by excluding the negligible effect of oxide-trap conductance,the model avoids the use of imaginary numbers and complex calculations,and thus is simple and intuitive.展开更多
Fluorine plasma treatment was used prior to the Schottky metal deposition on the undoped Al0.45Ga0.55N,which aimed at the solar-blind wavelength.After fluorine plasma treatment and before depositing the Ni/Au Schottky...Fluorine plasma treatment was used prior to the Schottky metal deposition on the undoped Al0.45Ga0.55N,which aimed at the solar-blind wavelength.After fluorine plasma treatment and before depositing the Ni/Au Schottky,the samples were thermal annealed in the N2 gas at 400 ℃.The reverse leakage current density of Al0.45Ga0.55N Schottky diode was reduced by 2 orders of magnitude at-10 V.The reverse leakage current density was reduced by 3 orders of magnitude after thermal annealing.Further capacitance-frequency analysis revealed that the fluorine-based plasma treatment reduces the surface states of AlGaN by one order of magnitude at different surface state energies.The capacitance-frequency analysis also proved that the concentration of carriers in AlGaN top is reduced through fluorine plasma treatment.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61176100 and 61274112)the University Development Fund of the University of Hong Kong,China(Grant No.00600009)the Hong Kong Polytechnic University,China(Grant No.1-ZVB1)
文摘An equivalent distributed capacitance model is established by considering only the gate oxide-trap capacitance to explain the frequency dispersion in the C-V curve of MOS capacitors measured for a frequency range from 1 kHz to1 MHz.The proposed model is based on the Fermi-Dirac statistics and the charging/discharging effects of the oxide traps induced by a small ac signal.The validity of the proposed model is confirmed by the good agreement between the simulated results and experimental data.Simulations indicate thatthe capacitance dispersion of an MOS capacitor under accumulation and near flatband is mainly caused by traps adjacent to the oxide/semiconductor interface,with negligible effects from the traps far from the interface,and the relevant distance from the interface at which the traps can still contribute to the gate capacitance is also discussed.In addition,by excluding the negligible effect of oxide-trap conductance,the model avoids the use of imaginary numbers and complex calculations,and thus is simple and intuitive.
文摘Fluorine plasma treatment was used prior to the Schottky metal deposition on the undoped Al0.45Ga0.55N,which aimed at the solar-blind wavelength.After fluorine plasma treatment and before depositing the Ni/Au Schottky,the samples were thermal annealed in the N2 gas at 400 ℃.The reverse leakage current density of Al0.45Ga0.55N Schottky diode was reduced by 2 orders of magnitude at-10 V.The reverse leakage current density was reduced by 3 orders of magnitude after thermal annealing.Further capacitance-frequency analysis revealed that the fluorine-based plasma treatment reduces the surface states of AlGaN by one order of magnitude at different surface state energies.The capacitance-frequency analysis also proved that the concentration of carriers in AlGaN top is reduced through fluorine plasma treatment.
