The current-voltage characteristics of 4H-SiC junction barrier Schottky （JBS） diodes terminated by an offset field plate have been measured in the temperature range of 25-300℃. An experimental barrier height value ...The current-voltage characteristics of 4H-SiC junction barrier Schottky （JBS） diodes terminated by an offset field plate have been measured in the temperature range of 25-300℃. An experimental barrier height value of about 0.5 eV is obtained for the Ti/4H-SiC JBS diodes at room temperature. A decrease in the experimental barrier height and an increase in the ideality factor with decreasing temperature are shown. Reverse recovery testing also shows the temperature dependence of the peak recovery current density and the reverse recovery time. Finally, a discussion of reducing the reverse recovery time is presented.展开更多
Surge current(SC)capability is one of the main aspects of reliability for silicon carbide(SiC)power devices.In this work,the influences of neutron radiation‐induced defects on the SC capability and reliability of Si...Surge current(SC)capability is one of the main aspects of reliability for silicon carbide(SiC)power devices.In this work,the influences of neutron radiation‐induced defects on the SC capability and reliability of SiC P‐intrinsic‐N(PiN)diodes were comprehensively investigated.It was found that the surge capability of the diodes can be deteriorated even under the slightly enhanced formation of carbon‐vacancy‐related Z_(1/2) and EH_(6/7 )defects introduced by neutron irradiation.Surprisingly,it was found that the forward voltage(V_(F))decreases with the increased SC and the stress cycles in the irradiated diodes,which is usually found to in-crease under the SC tests and attributed to the bipolar degradation(BPD).By using technology computer‐aided design simulation and deep‐level transient spectroscopy characterization,it was found that the sig-nificant self‐heating during surge stress leads to the annealing effect on the Z_(1/2) defects through the promoted recombination with the nearest and second neighbor carbon interstitials injected by irradiation,which thus plays a dominant role in the decrease of VF over the BPD.展开更多
A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to anal...A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMPATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation （~ 2%, i.e. small-signal conditions） results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode＇s negative conductance （5 × 106 S/m2）, susceptance （10.4 × 107 S/m2）, average breakdown voltage （207.6 V）, and power generating efficiency （15%, RF power： 25.0 W at 94 GHz） are obtained as a function of oscillation amplitude （50% of DC breakdown voltage） for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal （〉 50%） voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMPATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMPATT for possible application in high-power MM-wave communication systems.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 61006060)the 13115 Innovation Engineering of Shaanxi, China (Grant No. 2008ZDKG-30)the Key Laboratory Fund of Ministry of Education, China (Grant No. JY0100112501)
文摘The current-voltage characteristics of 4H-SiC junction barrier Schottky （JBS） diodes terminated by an offset field plate have been measured in the temperature range of 25-300℃. An experimental barrier height value of about 0.5 eV is obtained for the Ti/4H-SiC JBS diodes at room temperature. A decrease in the experimental barrier height and an increase in the ideality factor with decreasing temperature are shown. Reverse recovery testing also shows the temperature dependence of the peak recovery current density and the reverse recovery time. Finally, a discussion of reducing the reverse recovery time is presented.
基金National Natural Science Foundation of China,Grant/Award Number:12275244。
文摘Surge current(SC)capability is one of the main aspects of reliability for silicon carbide(SiC)power devices.In this work,the influences of neutron radiation‐induced defects on the SC capability and reliability of SiC P‐intrinsic‐N(PiN)diodes were comprehensively investigated.It was found that the surge capability of the diodes can be deteriorated even under the slightly enhanced formation of carbon‐vacancy‐related Z_(1/2) and EH_(6/7 )defects introduced by neutron irradiation.Surprisingly,it was found that the forward voltage(V_(F))decreases with the increased SC and the stress cycles in the irradiated diodes,which is usually found to in-crease under the SC tests and attributed to the bipolar degradation(BPD).By using technology computer‐aided design simulation and deep‐level transient spectroscopy characterization,it was found that the sig-nificant self‐heating during surge stress leads to the annealing effect on the Z_(1/2) defects through the promoted recombination with the nearest and second neighbor carbon interstitials injected by irradiation,which thus plays a dominant role in the decrease of VF over the BPD.
文摘A full-scale, self-consistent, non-linear, large-signal model of double-drift hetero-structure IMPATT diode with general doping profile is derived. This newly developed model, for the first time, has been used to analyze the large-signal characteristics of hexagonal SiC-based double-drift IMPATT diode. Considering the fabrication feasibility, the authors have studied the large-signal characteristics of Si/SiC-based hetero-structure devices. Under small-voltage modulation （~ 2%, i.e. small-signal conditions） results are in good agreement with calculations done using a linearised small-signal model. The large-signal values of the diode＇s negative conductance （5 × 106 S/m2）, susceptance （10.4 × 107 S/m2）, average breakdown voltage （207.6 V）, and power generating efficiency （15%, RF power： 25.0 W at 94 GHz） are obtained as a function of oscillation amplitude （50% of DC breakdown voltage） for a fixed average current density. The large-signal calculations exhibit power and efficiency saturation for large-signal （〉 50%） voltage modulation and thereafter decrease gradually with further increasing voltage-modulation. This generalized large-signal formulation is applicable for all types of IMPATT structures with distributed and narrow avalanche zones. The simulator is made more realistic by incorporating the space-charge effects, realistic field and temperature dependent material parameters in Si and SiC. The electric field snap-shots and the large-signal impedance and admittance of the diode with current excitation are expressed in closed loop form. This study will act as a guide for researchers to fabricate a high-power Si/SiC-based IMPATT for possible application in high-power MM-wave communication systems.
