In order to investigate their electrical characteristics, high-voltage light-emitting-diodes （HV-LEDs） each contain- ing four cells in series are fabricated. The electrical parameters including varying voltage and p...In order to investigate their electrical characteristics, high-voltage light-emitting-diodes （HV-LEDs） each contain- ing four cells in series are fabricated. The electrical parameters including varying voltage and parasitic effect are studied. It is shown that the ideality factors （IFs） of the HV-LEDs with different numbers of cells are 1.6, 3.4, 4.7, and 6.4. IF increases linearly with the number of cells increasing. Moreover, the performance of the HV-LED with failure cells is examined, The analysis indicates that the failure cell has a parallel resistance which induces the leakage of the failure cell. The series resistance of the failure cell is 76.8 Ω, while that of the normal cell is 21.3 Ω. The scanning electron microscope （SEM） image indicates that different metal layers do not contact well. It is hard to deposit the metal layers in the deep isolation trenches. The fabrication process of HV-LEDs needs to be optimized.展开更多
Fundamentals of the Schottky contacts and the high-temperature current conduction through three kinds of Schottky diodes are studied. N-Si Schottky diodes, GaN Schottky diodes and AlGaN/GaN Schottky diodes are investi...Fundamentals of the Schottky contacts and the high-temperature current conduction through three kinds of Schottky diodes are studied. N-Si Schottky diodes, GaN Schottky diodes and AlGaN/GaN Schottky diodes are investigated by I-V-T measurements ranging from 300 to 523 K. For these Schottky diodes, a rise in temperature is accompanied with an increase in barrier height and a reduction in ideality factor. Mechanisms are suggested, including thermionic emission, field emission, trap-assisted tunnelling and so on. The most remarkable finding in the present paper is that these three kinds of Schottky diodes are revealed to have different behaviours of high-temperature reverse currents. For the n-Si Schottky diode, a rise in temperature is accompanied by an increase in reverse current. The reverse current of the GaN Schottky diode decreases first and then increases with rising temperature. The AlGaN/GaN Schottky diode has a trend opposite to that of the GaN Schottky diode, and the dominant mechanisms are the effects of the piezoelectric polarization field and variation of two-dimensional electron gas charge density.展开更多
In this paper, the electrical parameters of Au/n-Si （MS） and Au/Si3N4/n-Si （MIS） Schottky diodes are obtained from the forward bias current-voltage （I-V） and capacitance-voltage （C-V） measurements at room temp...In this paper, the electrical parameters of Au/n-Si （MS） and Au/Si3N4/n-Si （MIS） Schottky diodes are obtained from the forward bias current-voltage （I-V） and capacitance-voltage （C-V） measurements at room temperature. Experimental results show that the rectifying ratios of the MS and MIS diodes at ± 5 V are found to be 1.25 ×103 and 1.27 ×104, respectively. The main electrical parameters of the MS and MIS diodes, such as the zero-bias barrier height （rbBo） and ideality factor （n）, are calculated to be 0.51 eV （I-V）, 0.53 eV （C-V）, and 4.43, and 0.65 eV （I-V）, 0.70 eV （C-V）, and 3.44, respectively. In addition, the energy density distribution profile of the interface states （Nss） is obtained from the forward bias I-V, and the series resistance （Rs） values for the two diodes are calculated from Cheung＇s method and Ohm＇s law.展开更多
Small high-quality Au/P-Si Schottky barrier diodes（SBDs） with an extremely low reverse leakage current using wet lithography were produced.Their effective barrier heights（BHs） and ideality factors from current-vol...Small high-quality Au/P-Si Schottky barrier diodes（SBDs） with an extremely low reverse leakage current using wet lithography were produced.Their effective barrier heights（BHs） and ideality factors from current-voltage （Ⅰ-Ⅴ） characteristics were measured by a conducting probe atomic force microscope（C-AFM）.In spite of the identical preparation of the diodes there was a diode-to-diode variation in ideality factor and barrier height parameters.By extrapolating the plots the built in potential of the Au /p-Si contact was obtained as V_（bi）=0.5425 V and the barrier height valueΦ_（b（c-V）） was calculated to beΦ_（B（C-V））=0.7145 V for Au/p-Si.It is found that for the diodes with diameters smaller than 100μm,the diode barrier height and ideality factor dependency to their diameters and correlation between the diode barrier height and its ideality factor are nonlinear,where similar to the earlier reported different metal semiconductor diodes in the literature,these parameters for the here manufactured diodes with diameters more than 100μm are also linear.Based on the very obvious sub-nanometer C-AFM produced pictures the scientific evidence behind this controversy is also explained.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11002013201102)the National Key Technology R & D Program of China(Grant No.2011BAE01B14)
文摘In order to investigate their electrical characteristics, high-voltage light-emitting-diodes （HV-LEDs） each contain- ing four cells in series are fabricated. The electrical parameters including varying voltage and parasitic effect are studied. It is shown that the ideality factors （IFs） of the HV-LEDs with different numbers of cells are 1.6, 3.4, 4.7, and 6.4. IF increases linearly with the number of cells increasing. Moreover, the performance of the HV-LED with failure cells is examined, The analysis indicates that the failure cell has a parallel resistance which induces the leakage of the failure cell. The series resistance of the failure cell is 76.8 Ω, while that of the normal cell is 21.3 Ω. The scanning electron microscope （SEM） image indicates that different metal layers do not contact well. It is hard to deposit the metal layers in the deep isolation trenches. The fabrication process of HV-LEDs needs to be optimized.
基金Project supported by the Foundation of Key Laboratory of General Armament Department, China (Grant No 5132030102QT0101)
文摘Fundamentals of the Schottky contacts and the high-temperature current conduction through three kinds of Schottky diodes are studied. N-Si Schottky diodes, GaN Schottky diodes and AlGaN/GaN Schottky diodes are investigated by I-V-T measurements ranging from 300 to 523 K. For these Schottky diodes, a rise in temperature is accompanied with an increase in barrier height and a reduction in ideality factor. Mechanisms are suggested, including thermionic emission, field emission, trap-assisted tunnelling and so on. The most remarkable finding in the present paper is that these three kinds of Schottky diodes are revealed to have different behaviours of high-temperature reverse currents. For the n-Si Schottky diode, a rise in temperature is accompanied by an increase in reverse current. The reverse current of the GaN Schottky diode decreases first and then increases with rising temperature. The AlGaN/GaN Schottky diode has a trend opposite to that of the GaN Schottky diode, and the dominant mechanisms are the effects of the piezoelectric polarization field and variation of two-dimensional electron gas charge density.
基金supported by Gazi University Scientific Research Project (BAP),FEF. 05/2012-15
文摘In this paper, the electrical parameters of Au/n-Si （MS） and Au/Si3N4/n-Si （MIS） Schottky diodes are obtained from the forward bias current-voltage （I-V） and capacitance-voltage （C-V） measurements at room temperature. Experimental results show that the rectifying ratios of the MS and MIS diodes at ± 5 V are found to be 1.25 ×103 and 1.27 ×104, respectively. The main electrical parameters of the MS and MIS diodes, such as the zero-bias barrier height （rbBo） and ideality factor （n）, are calculated to be 0.51 eV （I-V）, 0.53 eV （C-V）, and 4.43, and 0.65 eV （I-V）, 0.70 eV （C-V）, and 3.44, respectively. In addition, the energy density distribution profile of the interface states （Nss） is obtained from the forward bias I-V, and the series resistance （Rs） values for the two diodes are calculated from Cheung＇s method and Ohm＇s law.
文摘Small high-quality Au/P-Si Schottky barrier diodes（SBDs） with an extremely low reverse leakage current using wet lithography were produced.Their effective barrier heights（BHs） and ideality factors from current-voltage （Ⅰ-Ⅴ） characteristics were measured by a conducting probe atomic force microscope（C-AFM）.In spite of the identical preparation of the diodes there was a diode-to-diode variation in ideality factor and barrier height parameters.By extrapolating the plots the built in potential of the Au /p-Si contact was obtained as V_（bi）=0.5425 V and the barrier height valueΦ_（b（c-V）） was calculated to beΦ_（B（C-V））=0.7145 V for Au/p-Si.It is found that for the diodes with diameters smaller than 100μm,the diode barrier height and ideality factor dependency to their diameters and correlation between the diode barrier height and its ideality factor are nonlinear,where similar to the earlier reported different metal semiconductor diodes in the literature,these parameters for the here manufactured diodes with diameters more than 100μm are also linear.Based on the very obvious sub-nanometer C-AFM produced pictures the scientific evidence behind this controversy is also explained.
