Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemi...Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode,in which N-type ZnO and P-type CuO are constricted to a PN junction.This paper comprehensively discusses the material properties,morphology,semiconductor characteristics,and exploding performances of the energetic diode.Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3×10^(-4)A.When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s,the loaded power can excite the energetic diode exploding and the current rises to about100 A.Due to the unique performance of the energetic diode,it has a double function of rectification and explosion.The energetic diode can be used as a logic element in the normal chip to complete the regular operation,and it can release energy to destroy the chip accurately.展开更多
The trench diamond junction barrier Schottky(JBS)diode with a sidewall enhanced structure is designed by Silvaco simulation.Comparing with the conventional trench JBS diode,Schottky contact areas are introduced on the...The trench diamond junction barrier Schottky(JBS)diode with a sidewall enhanced structure is designed by Silvaco simulation.Comparing with the conventional trench JBS diode,Schottky contact areas are introduced on the sidewall of the trench beside the top cathode.The sidewall Schottky contact weakens the junction field-effect transistor effect between the trenches to realize a low on-resistance and a high Baliga's figure of merit(FOM)value.In addition,the existence of the n-type diamond helps to suppress the electric field crowding effect and enhance the reverse breakdown voltage.With the optimal parameters of device structure,a high Baliga's FOM value of 2.28 GW/cm^(2) is designed.Therefore,the proposed sidewall-enhanced trench JBS diode is a promising component for the applications in diamond power electronics.展开更多
A vertical junction barrier Schottky diode with a high-K/low-K compound dielectric structure is proposed and optimized to achieve a high breakdown voltage(BV).There is a discontinuity of the electric field at the inte...A vertical junction barrier Schottky diode with a high-K/low-K compound dielectric structure is proposed and optimized to achieve a high breakdown voltage(BV).There is a discontinuity of the electric field at the interface of high-K and low-K layers due to the different dielectric constants of high-K and low-K dielectric layers.A new electric field peak is introduced in the n-type drift region of junction barrier Schottky diode(JBS),so the distribution of electric field in JBS becomes more uniform.At the same time,the effect of electric-power line concentration at the p-n junction interface is suppressed due to the effects of the high-K dielectric layer and an enhancement of breakdown voltage can be achieved.Numerical simulations demonstrate that GaN JBS with a specific on-resistance(R_(on,sp)) of 2.07 mΩ·cm^(2) and a BV of 4171 V which is 167% higher than the breakdown voltage of the common structure,resulting in a high figure-of-merit(FOM) of 8.6 GW/cm^(2),and a low turn-on voltage of 0.6 V.展开更多
By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conductio...By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conduction characteristic is demonstrated by the verification of temperature-dependent current–voltage(I–V) tests and electroluminescence spectra.Meanwhile, apparently advantageous forward conduction properties as compared to the pn diode fabricated on the same wafer have been achieved, featuring a lower turn-on voltage of 0.82 V. Together with the analysis model established in the GaN SPND for a wide-range designable turn-on voltage, this work provides an alternative method to the GaN rectifier strategies besides the traditional solution.展开更多
This work demonstrates high-performance NiO/β-Ga_(2)O_(3) vertical heterojunction diodes(HJDs)with double-layer junc-tion termination extension(DL-JTE)consisting of two p-typed NiO layers with varied lengths.The bott...This work demonstrates high-performance NiO/β-Ga_(2)O_(3) vertical heterojunction diodes(HJDs)with double-layer junc-tion termination extension(DL-JTE)consisting of two p-typed NiO layers with varied lengths.The bottom 60-nm p-NiO layer fully covers theβ-Ga_(2)O_(3) wafer,while the geometry of the upper 60-nm p-NiO layer is 10μm larger than the square anode elec-trode.Compared with a single-layer JTE,the electric field concentration is inhibited by double-layer JTE structure effectively,resulting in the breakdown voltage being improved from 2020 to 2830 V.Moreover,double p-typed NiO layers allow more holes into the Ga_(2)O_(3) drift layer to reduce drift resistance.The specific on-resistance is reduced from 1.93 to 1.34 mΩ·cm^(2).The device with DL-JTE shows a power figure-of-merit(PFOM)of 5.98 GW/cm^(2),which is 2.8 times larger than that of the conven-tional single-layer JTE structure.These results indicate that the double-layer JTE structure provides a viable way of fabricating high-performance Ga_(2)O_(3) HJDs.展开更多
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
Mesa width (WM) is a key design parameter for SiC super junction (SJ) Schottky diodes (SBD) fabricated by the trench-etching-and-sidewall-implant method. This paper carries out a comprehensive investigation on h...Mesa width (WM) is a key design parameter for SiC super junction (SJ) Schottky diodes (SBD) fabricated by the trench-etching-and-sidewall-implant method. This paper carries out a comprehensive investigation on how the mesa width design determines the device electrical performances and how it affects the degree of performance degradation induced by process variations. It is found that structures designed with narrower mesa widths can tolerant substantially larger charge imbalance for a given BV target, but have poor specific on-resistances. On the contrary, structures with wider mesa widths have superior on-state performances but their breakdown voltages are more sensitive to p-type doping variation. Medium WM structures (-2 p.m) exhibit stronger robustness against the process variation resulting from SiC deep trench etching. Devices with 2-p.m mesa width were fabricated and electrically characterized. The fabricated SiC SJ SBDs have achieved a breakdown voltage of 1350 V with a specific on-resistance as low as 0.98 mΩ2.cm2. The estimated specific drift on- resistance by subtracting substrate resistance is well below the theoretical one-dimensional unipolar limit of SiC material. The robustness of the voltage blocking capability against trench dimension variations has also been experimentally verified for the proposed SiC SJ SBD devices.展开更多
This paper stuides the structures of 4H SiC floating junction Schottky barrier diodes. Some structure parameters of devices are optimized with commercial simulator based on forward and reverse electrical characteristi...This paper stuides the structures of 4H SiC floating junction Schottky barrier diodes. Some structure parameters of devices are optimized with commercial simulator based on forward and reverse electrical characteristics. Compared with conventional power Schottky barrier diodes, the devices are featured by highly doped drift region and embedded floating junction layers, which can ensure high breakdown voltage while keeping lower specific on-state resistance, and solve the contradiction between forward voltage drop and breakdown voltage. The simulation results show that with optimized structure parameter, the breakdown voltage can reach 4.36 kV and the specific on-resistance is 5.8 mΩ.cm2 when the Baliga figure of merit value of 13.1 GW/cm2 is achieved.展开更多
This paper develops a new and easy to implement analytical model for the specific on-resistance and electric field distribution along the critical path for 4H-SiC multi-floating junction Schottky barrier diode. Consid...This paper develops a new and easy to implement analytical model for the specific on-resistance and electric field distribution along the critical path for 4H-SiC multi-floating junction Schottky barrier diode. Considering the charge compensation effects by the multilayer of buried opposite doped regions, it improves the breakdown voltage a lot in comparison with conventional one with the same on-resistance. The forward resistance of the floating junction Schottky barrier diode consists of several components and the electric field can be understood with superposition concept, both are consistent with MEDICI simulation results. Moreover, device parameters are optimized and the analyses show that in comparison with one layer floating junction, multilayer of floating junction layer is an effective way to increase the device performance when specific resistance and the breakdown voltage are traded off. The results show that the specific resistance increases 3.2 mΩ.cm2 and breakdown voltage increases 422 V with an additional floating junction for the given structure.展开更多
Schottky diodes and PN junctions were utilized as energy converting structures in ZnO-based betavoltaic batteries,in which 0.101121 Ci 63Ni was selected as the beta source.The time-related electrical properties were o...Schottky diodes and PN junctions were utilized as energy converting structures in ZnO-based betavoltaic batteries,in which 0.101121 Ci 63Ni was selected as the beta source.The time-related electrical properties were obtained using Monte Carlo simulations.For the n-type ZnO,the Pt/ZnO Schottky diode had the highest energy conversion efficiency,and the Ni/ZnO Schottky diode had the largest Isc.The overall electrical performance of PN junctions is better than that of Schottky diodes.The lifetimes of Pt/ZnO and Ni/ZnO are longer than for other Schottky devices,coming close to those of PN junctions.Considering that Schottky diodes are easier to fabricate and independent of p-type semiconductors,Pt/ZnO and Ni/ZnO diodes offer alternatives to PN-junction-based betavoltaic batteries.展开更多
This paper proposes a novel super junction (S J) SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained ...This paper proposes a novel super junction (S J) SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained SiGe p+ layer to overcome the drawbacks of existing Si switching power diode. The SJ SiGe diode can achieve low specific on-resistance, high breakdown voltages and fast switching speed. The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm^2, which is very good for getting lower operating loss. The forward voltage drop of the Si diode is 0.66V whereas that of the SJ SiGe diode is only 0.52V voltages are 203 V for the former and 235 V for the latter. at operating current density of 10A/cm^2. The breakdown Compared with the conventional Si power diode, the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%. The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material.展开更多
The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional de...The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional device simulator ISE-TCAD10.0. By experimental verification, a good consistency between simulation and experiment can be observed. The results show that the reverse breakdown voltage for the 4H-SiC P-i-N diode with optimized JTE edge termination can accomplish near ideal breakdown voltage and much lower leakage current. The breakdown voltage can be near 1650 V, which achieves more than 90 percent of ideal parallel plane junction breakdown voltage and the leakage current density can be near 3 ×10^-5 A/cm2.展开更多
This paper reports that the 4H-SiC Schottky barrier diode, PiN diode and junction barrier Schottky diode terminated by field guard rings are designed, fabricated and characterised. The measurements for forward and rev...This paper reports that the 4H-SiC Schottky barrier diode, PiN diode and junction barrier Schottky diode terminated by field guard rings are designed, fabricated and characterised. The measurements for forward and reverse characteristics have been done, and by comparison with each other, it shows that junction barrier Schottky diode has a lower reverse current density than that of the Schottky barrier diode and a higher forward drop than that of the PiN diode. High-temperature annealing is presented in this paper as well to figure out an optimised processing. The barrier height of 0.79 eV is formed with Ti in this work, the forward drop for the Schottky diode is 2.1 V, with an ideality factor of 3.2, and junction barrier Schottky diode with blocking voltage higher than 400 V was achieved by using field guard ring termination.展开更多
A novel diode string-triggered gated-Pi N junction device, which is fabricated in a standard 65-nm complementary metal-oxide semiconductor(CMOS) technology, is proposed in this paper. An embedded gated-Pi N junction...A novel diode string-triggered gated-Pi N junction device, which is fabricated in a standard 65-nm complementary metal-oxide semiconductor(CMOS) technology, is proposed in this paper. An embedded gated-Pi N junction structure is employed to reduce the diode string leakage current to 13 n A/μm in a temperature range from 25°C to 85°C. To provide the effective electrostatic discharge(ESD) protection in multi-voltage power supply, the triggering voltage of the novel device can be adjusted through redistributing parasitic resistance instead of changing the stacked diode number.展开更多
4H-SiC junction barrier Schottky (JBS) diodes with a high-temperature annealed resistive termination extension (HARTE) are designed, fabricated and characterized in this work. The differential specific on-state re...4H-SiC junction barrier Schottky (JBS) diodes with a high-temperature annealed resistive termination extension (HARTE) are designed, fabricated and characterized in this work. The differential specific on-state resistance of the device is as low as 3.64 mΩ·cm^2 with a total active area of 2.46× 10 ^-3 cm^2. Ti is the Schottky contact metal with a Schottky barrier height of 1.08 V and a low onset voltage of 0.7 V. The ideality factor is calculated to be 1.06. Al implantation annealing is performed at 1250 ℃ in Ar, while good reverse characteristics are achieved. The maximum breakdown voltage is 1000 V with a leakage current of 9× 10^-5 A on chip level. These experimental results show good consistence with the simulation results and demonstrate that high-performance 4H-SiC JBS diodes can be obtained based on the double HARTE structure.展开更多
We report on the fabrications and characterizations of axial and radial Ga As nanowire pn junction diode arrays.The nanowires are grown on n-doped Ga As(111)B substrates using the Au-catalyzed vapor–liquid–solid m...We report on the fabrications and characterizations of axial and radial Ga As nanowire pn junction diode arrays.The nanowires are grown on n-doped Ga As(111)B substrates using the Au-catalyzed vapor–liquid–solid mechanism by metal–organic chemical vapor deposition(MOCVD). Diethyl–zinc and silane are used as p- and n-type dopant precursors,respectively. Both the axial and radial diodes exhibit diode-like J–V characteristics and have similar performances under forward bias. Under backward bias, the axial diode has a large leakage current, which is attributed to the bending of the pn junction interface induced by two doping mechanisms in Au-catalyzed nanowires. The low leakage current and high rectification ratio make the radial diode more promising in electrical and optoelectronic devices.展开更多
A novel junction terminal extension structure is proposed for vertical diamond Schottky barrier diodes(SBDs) by using an n-Ga_(2)O_(3)/p-diamond heterojunction. The depletion region of the heterojunction suppresses pa...A novel junction terminal extension structure is proposed for vertical diamond Schottky barrier diodes(SBDs) by using an n-Ga_(2)O_(3)/p-diamond heterojunction. The depletion region of the heterojunction suppresses part of the forward current conduction path, which slightly increases the on-resistance. On the other hand, the reverse breakdown voltage is enhanced obviously because of attenuated electric field crowding. By optimizing the doping concentration, length, and depth of n-Ga_(2)O_(3), the trade-off between on-resistance and breakdown voltage with a high Baliga figure of merit(FOM)value is realized through Silvaco technology computer-aided design simulation. In addition, the effect of the work functions of the Schottky electrodes is evaluated. The results are beneficial to realizing a high-performance vertical diamond SBD.展开更多
In this paper, a mixed terminal structure for the 4H-SiC merged PiN/Schottky diode (MPS) is investigated, which is a combination of a field plate, a junction termination extension and floating limiting rings. Optimi...In this paper, a mixed terminal structure for the 4H-SiC merged PiN/Schottky diode (MPS) is investigated, which is a combination of a field plate, a junction termination extension and floating limiting rings. Optimization is performed on the terminal structure by using the ISE-TCAD. Further analysis shows that this structure can greatly reduce the sensitivity of the breakdown voltage to the doping concentration and can effectively suppress the effect of the interface charge compared with the structure of the junction termination extension. At the same time, the 4H-SiC MPS with this termination structure can reach a high and stable breakdown voltage.展开更多
Silicon p–i–n diodes with different i-region widths are fabricated and tested. It is found that the current shows the non-monotonic behavior as a function of i-region width at a bias voltage of 1.0 V. In this paper,...Silicon p–i–n diodes with different i-region widths are fabricated and tested. It is found that the current shows the non-monotonic behavior as a function of i-region width at a bias voltage of 1.0 V. In this paper, an analytical model is presented to explain the non-monotonic behavior, which mainly takes into account the diffusion current and recombination current contributing to the total current. The calculation results indicate that the concentration ratio of p-region to n-region plays a crucial role in the non-monotonic behavior, and the carrier lifetime also has a great influence on this abnormal phenomenon.展开更多
4H silicon carbide(4H-SiC) junction barrier Schottky(JBS) diode with breakdown voltage higher than 2.7 kV and active area of 2.8 mm2 has been successfully fabricated.The design,the fabrication,and the electrical c...4H silicon carbide(4H-SiC) junction barrier Schottky(JBS) diode with breakdown voltage higher than 2.7 kV and active area of 2.8 mm2 has been successfully fabricated.The design,the fabrication,and the electrical characteristics are reported.Numerical simulations have been performed to select the doping level and thickness of the drift layer and the effectiveness of the edge termination technique.The epilayer properties of the N-type are 18μm with a doping of 3.5×1015 cm-3.The diodes are fabricated with a floating guard rings edge termination.The on-state voltage is 2.15 V at Jf=350 A·cm-2.展开更多
基金the National Natural Science Foundation of China(Grant Nos.22275092,52372084)the Fundamental Research Funds for the Central Universities(Grant No.30923010920)。
文摘Self-destructing chips have promising applications for securing data.This paper proposes a new concept of energetic diodes for the first time,which can be used for self-destructive chips.A simple two-step electrochemical deposition method is used to prepare ZnO/CuO/Al energetic diode,in which N-type ZnO and P-type CuO are constricted to a PN junction.This paper comprehensively discusses the material properties,morphology,semiconductor characteristics,and exploding performances of the energetic diode.Experimental results show that the energetic diode has typical rectification with a turn-on voltage of about 1.78 V and a reverse leakage current of about 3×10^(-4)A.When a constant voltage of 70 V loads to the energetic diode in the forward direction for about 0.14 s or 55 V loads in the reverse direction for about 0.17 s,the loaded power can excite the energetic diode exploding and the current rises to about100 A.Due to the unique performance of the energetic diode,it has a double function of rectification and explosion.The energetic diode can be used as a logic element in the normal chip to complete the regular operation,and it can release energy to destroy the chip accurately.
基金Project supported by the Key Research and Development Program of Guangdong Province,China(Grant No.2020B0101690001)the Natural Science Foundation of Sichuan Province,China(Grant No.2022NSFSC0886)the Open Project of State Key Laboratory of Superhard Materials,Jilin Province,China(Grant No.202314)。
文摘The trench diamond junction barrier Schottky(JBS)diode with a sidewall enhanced structure is designed by Silvaco simulation.Comparing with the conventional trench JBS diode,Schottky contact areas are introduced on the sidewall of the trench beside the top cathode.The sidewall Schottky contact weakens the junction field-effect transistor effect between the trenches to realize a low on-resistance and a high Baliga's figure of merit(FOM)value.In addition,the existence of the n-type diamond helps to suppress the electric field crowding effect and enhance the reverse breakdown voltage.With the optimal parameters of device structure,a high Baliga's FOM value of 2.28 GW/cm^(2) is designed.Therefore,the proposed sidewall-enhanced trench JBS diode is a promising component for the applications in diamond power electronics.
基金Project supported by the National Natural Science Foundation of China (Grant No.61376078)the Natural Science Foundation of Sichuan Province,China (Grant No.2022NSFSC0515)。
文摘A vertical junction barrier Schottky diode with a high-K/low-K compound dielectric structure is proposed and optimized to achieve a high breakdown voltage(BV).There is a discontinuity of the electric field at the interface of high-K and low-K layers due to the different dielectric constants of high-K and low-K dielectric layers.A new electric field peak is introduced in the n-type drift region of junction barrier Schottky diode(JBS),so the distribution of electric field in JBS becomes more uniform.At the same time,the effect of electric-power line concentration at the p-n junction interface is suppressed due to the effects of the high-K dielectric layer and an enhancement of breakdown voltage can be achieved.Numerical simulations demonstrate that GaN JBS with a specific on-resistance(R_(on,sp)) of 2.07 mΩ·cm^(2) and a BV of 4171 V which is 167% higher than the breakdown voltage of the common structure,resulting in a high figure-of-merit(FOM) of 8.6 GW/cm^(2),and a low turn-on voltage of 0.6 V.
基金supported by the National Natural Science Foundation of China (Grant Nos. U2141241, 62004099, 61921005,and 91850112)。
文摘By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode(SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conduction characteristic is demonstrated by the verification of temperature-dependent current–voltage(I–V) tests and electroluminescence spectra.Meanwhile, apparently advantageous forward conduction properties as compared to the pn diode fabricated on the same wafer have been achieved, featuring a lower turn-on voltage of 0.82 V. Together with the analysis model established in the GaN SPND for a wide-range designable turn-on voltage, this work provides an alternative method to the GaN rectifier strategies besides the traditional solution.
基金supported by the National Natural Science Foundation of China under Grant U21A20503.
文摘This work demonstrates high-performance NiO/β-Ga_(2)O_(3) vertical heterojunction diodes(HJDs)with double-layer junc-tion termination extension(DL-JTE)consisting of two p-typed NiO layers with varied lengths.The bottom 60-nm p-NiO layer fully covers theβ-Ga_(2)O_(3) wafer,while the geometry of the upper 60-nm p-NiO layer is 10μm larger than the square anode elec-trode.Compared with a single-layer JTE,the electric field concentration is inhibited by double-layer JTE structure effectively,resulting in the breakdown voltage being improved from 2020 to 2830 V.Moreover,double p-typed NiO layers allow more holes into the Ga_(2)O_(3) drift layer to reduce drift resistance.The specific on-resistance is reduced from 1.93 to 1.34 mΩ·cm^(2).The device with DL-JTE shows a power figure-of-merit(PFOM)of 5.98 GW/cm^(2),which is 2.8 times larger than that of the conven-tional single-layer JTE structure.These results indicate that the double-layer JTE structure provides a viable way of fabricating high-performance Ga_(2)O_(3) HJDs.
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Project supported by the National Key Research and Development Program of China(Grant No.2016YFB0400502)the National Natural Science Foundation of China(Grant Nos.U1766222 and 51777187)
文摘Mesa width (WM) is a key design parameter for SiC super junction (SJ) Schottky diodes (SBD) fabricated by the trench-etching-and-sidewall-implant method. This paper carries out a comprehensive investigation on how the mesa width design determines the device electrical performances and how it affects the degree of performance degradation induced by process variations. It is found that structures designed with narrower mesa widths can tolerant substantially larger charge imbalance for a given BV target, but have poor specific on-resistances. On the contrary, structures with wider mesa widths have superior on-state performances but their breakdown voltages are more sensitive to p-type doping variation. Medium WM structures (-2 p.m) exhibit stronger robustness against the process variation resulting from SiC deep trench etching. Devices with 2-p.m mesa width were fabricated and electrically characterized. The fabricated SiC SJ SBDs have achieved a breakdown voltage of 1350 V with a specific on-resistance as low as 0.98 mΩ2.cm2. The estimated specific drift on- resistance by subtracting substrate resistance is well below the theoretical one-dimensional unipolar limit of SiC material. The robustness of the voltage blocking capability against trench dimension variations has also been experimentally verified for the proposed SiC SJ SBD devices.
基金Project supported by the Open Fund of Key Laboratory of Wide Bandgap Semiconductor Materials and Devices, Ministry of Education of China
文摘This paper stuides the structures of 4H SiC floating junction Schottky barrier diodes. Some structure parameters of devices are optimized with commercial simulator based on forward and reverse electrical characteristics. Compared with conventional power Schottky barrier diodes, the devices are featured by highly doped drift region and embedded floating junction layers, which can ensure high breakdown voltage while keeping lower specific on-state resistance, and solve the contradiction between forward voltage drop and breakdown voltage. The simulation results show that with optimized structure parameter, the breakdown voltage can reach 4.36 kV and the specific on-resistance is 5.8 mΩ.cm2 when the Baliga figure of merit value of 13.1 GW/cm2 is achieved.
基金Project supported by the Open Fund of Key Laboratory of Wide Bandgap Semiconductor Materials and Devices, Ministry of Education of China
文摘This paper develops a new and easy to implement analytical model for the specific on-resistance and electric field distribution along the critical path for 4H-SiC multi-floating junction Schottky barrier diode. Considering the charge compensation effects by the multilayer of buried opposite doped regions, it improves the breakdown voltage a lot in comparison with conventional one with the same on-resistance. The forward resistance of the floating junction Schottky barrier diode consists of several components and the electric field can be understood with superposition concept, both are consistent with MEDICI simulation results. Moreover, device parameters are optimized and the analyses show that in comparison with one layer floating junction, multilayer of floating junction layer is an effective way to increase the device performance when specific resistance and the breakdown voltage are traded off. The results show that the specific resistance increases 3.2 mΩ.cm2 and breakdown voltage increases 422 V with an additional floating junction for the given structure.
基金supported by the National Major Scientific Instruments and Equipment Development Projects(No.2012YQ240121)National Natural Science Foundation of China(No.11075064)
文摘Schottky diodes and PN junctions were utilized as energy converting structures in ZnO-based betavoltaic batteries,in which 0.101121 Ci 63Ni was selected as the beta source.The time-related electrical properties were obtained using Monte Carlo simulations.For the n-type ZnO,the Pt/ZnO Schottky diode had the highest energy conversion efficiency,and the Ni/ZnO Schottky diode had the largest Isc.The overall electrical performance of PN junctions is better than that of Schottky diodes.The lifetimes of Pt/ZnO and Ni/ZnO are longer than for other Schottky devices,coming close to those of PN junctions.Considering that Schottky diodes are easier to fabricate and independent of p-type semiconductors,Pt/ZnO and Ni/ZnO diodes offer alternatives to PN-junction-based betavoltaic batteries.
基金Project supported by the National Natural Science Foundation of China (Grant No 50477012)the Doctoral Program Foundation of Institutes of Higher Education of China (Grant No 20050700006)the Special Scientific Research Program of the Education Bureau of Shaanxi Province,China (Grant No 05JK268)
文摘This paper proposes a novel super junction (S J) SiGe switching power diode which has a columnar structure of alternating p- and n- doped pillar substituting conventional n- base region and has far thinner strained SiGe p+ layer to overcome the drawbacks of existing Si switching power diode. The SJ SiGe diode can achieve low specific on-resistance, high breakdown voltages and fast switching speed. The results indicate that the forward voltage drop of SJ SiGe diode is much lower than that of conventional Si power diode when the operating current densities do not exceed 1000 A/cm^2, which is very good for getting lower operating loss. The forward voltage drop of the Si diode is 0.66V whereas that of the SJ SiGe diode is only 0.52V voltages are 203 V for the former and 235 V for the latter. at operating current density of 10A/cm^2. The breakdown Compared with the conventional Si power diode, the reverse recovery time of SJ SiGe diode with 20 per cent Ge content is shortened by above a half and the peak reverse current is reduced by over 15%. The SJ SiGe diode can remarkably improve the characteristics of power diode by combining the merits of both SJ structure and SiGe material.
基金Project supported by the Science and Technology Foundation of Hunan Province of China (Grant No. 2008FJ3102)
文摘The planar edge termination techniques of junction termination extension (JTE) and offset field plates and fieldlimiting rings for the 4H-SiC P i-N diode were investigated and optimized by using a two-dimensional device simulator ISE-TCAD10.0. By experimental verification, a good consistency between simulation and experiment can be observed. The results show that the reverse breakdown voltage for the 4H-SiC P-i-N diode with optimized JTE edge termination can accomplish near ideal breakdown voltage and much lower leakage current. The breakdown voltage can be near 1650 V, which achieves more than 90 percent of ideal parallel plane junction breakdown voltage and the leakage current density can be near 3 ×10^-5 A/cm2.
基金supported by the 13115 Innovation Engineering of Shanxi (Grant No.2008ZDKG-30)
文摘This paper reports that the 4H-SiC Schottky barrier diode, PiN diode and junction barrier Schottky diode terminated by field guard rings are designed, fabricated and characterised. The measurements for forward and reverse characteristics have been done, and by comparison with each other, it shows that junction barrier Schottky diode has a lower reverse current density than that of the Schottky barrier diode and a higher forward drop than that of the PiN diode. High-temperature annealing is presented in this paper as well to figure out an optimised processing. The barrier height of 0.79 eV is formed with Ti in this work, the forward drop for the Schottky diode is 2.1 V, with an ideality factor of 3.2, and junction barrier Schottky diode with blocking voltage higher than 400 V was achieved by using field guard ring termination.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00606)
文摘A novel diode string-triggered gated-Pi N junction device, which is fabricated in a standard 65-nm complementary metal-oxide semiconductor(CMOS) technology, is proposed in this paper. An embedded gated-Pi N junction structure is employed to reduce the diode string leakage current to 13 n A/μm in a temperature range from 25°C to 85°C. To provide the effective electrostatic discharge(ESD) protection in multi-voltage power supply, the triggering voltage of the novel device can be adjusted through redistributing parasitic resistance instead of changing the stacked diode number.
基金supported by the National Natural Science Foundation of China (Grant No. 51102225)the Natural Science Foundation of Beijing City, China (Grant No. 4132076)the Youth Innovation Promotion Association, Chinese Academy of Sciences
文摘4H-SiC junction barrier Schottky (JBS) diodes with a high-temperature annealed resistive termination extension (HARTE) are designed, fabricated and characterized in this work. The differential specific on-state resistance of the device is as low as 3.64 mΩ·cm^2 with a total active area of 2.46× 10 ^-3 cm^2. Ti is the Schottky contact metal with a Schottky barrier height of 1.08 V and a low onset voltage of 0.7 V. The ideality factor is calculated to be 1.06. Al implantation annealing is performed at 1250 ℃ in Ar, while good reverse characteristics are achieved. The maximum breakdown voltage is 1000 V with a leakage current of 9× 10^-5 A on chip level. These experimental results show good consistence with the simulation results and demonstrate that high-performance 4H-SiC JBS diodes can be obtained based on the double HARTE structure.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61376019 and 61020106007)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20120005110011)+2 种基金the Natural Science Foundation of Beijing(Grant No.4142038)the 111 Program of China(Grant No.B07005)the Fund of the State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)
文摘We report on the fabrications and characterizations of axial and radial Ga As nanowire pn junction diode arrays.The nanowires are grown on n-doped Ga As(111)B substrates using the Au-catalyzed vapor–liquid–solid mechanism by metal–organic chemical vapor deposition(MOCVD). Diethyl–zinc and silane are used as p- and n-type dopant precursors,respectively. Both the axial and radial diodes exhibit diode-like J–V characteristics and have similar performances under forward bias. Under backward bias, the axial diode has a large leakage current, which is attributed to the bending of the pn junction interface induced by two doping mechanisms in Au-catalyzed nanowires. The low leakage current and high rectification ratio make the radial diode more promising in electrical and optoelectronic devices.
基金Project supported by the Key Research and Development Program of Guangdong Province, China (Grant No. 2020B0101690001)the Natural Science Foundation of Sichuan Province, China (Grant No. 2022NSFSC0886)。
文摘A novel junction terminal extension structure is proposed for vertical diamond Schottky barrier diodes(SBDs) by using an n-Ga_(2)O_(3)/p-diamond heterojunction. The depletion region of the heterojunction suppresses part of the forward current conduction path, which slightly increases the on-resistance. On the other hand, the reverse breakdown voltage is enhanced obviously because of attenuated electric field crowding. By optimizing the doping concentration, length, and depth of n-Ga_(2)O_(3), the trade-off between on-resistance and breakdown voltage with a high Baliga figure of merit(FOM)value is realized through Silvaco technology computer-aided design simulation. In addition, the effect of the work functions of the Schottky electrodes is evaluated. The results are beneficial to realizing a high-performance vertical diamond SBD.
基金supported by the National Natural Science Foundation of China(Grant No.61006060)the Shaanxi Provincial 13115 Innovation Engineering,China(Grant No.2008ZDKG-30)
文摘In this paper, a mixed terminal structure for the 4H-SiC merged PiN/Schottky diode (MPS) is investigated, which is a combination of a field plate, a junction termination extension and floating limiting rings. Optimization is performed on the terminal structure by using the ISE-TCAD. Further analysis shows that this structure can greatly reduce the sensitivity of the breakdown voltage to the doping concentration and can effectively suppress the effect of the interface charge compared with the structure of the junction termination extension. At the same time, the 4H-SiC MPS with this termination structure can reach a high and stable breakdown voltage.
文摘Silicon p–i–n diodes with different i-region widths are fabricated and tested. It is found that the current shows the non-monotonic behavior as a function of i-region width at a bias voltage of 1.0 V. In this paper, an analytical model is presented to explain the non-monotonic behavior, which mainly takes into account the diffusion current and recombination current contributing to the total current. The calculation results indicate that the concentration ratio of p-region to n-region plays a crucial role in the non-monotonic behavior, and the carrier lifetime also has a great influence on this abnormal phenomenon.
文摘4H silicon carbide(4H-SiC) junction barrier Schottky(JBS) diode with breakdown voltage higher than 2.7 kV and active area of 2.8 mm2 has been successfully fabricated.The design,the fabrication,and the electrical characteristics are reported.Numerical simulations have been performed to select the doping level and thickness of the drift layer and the effectiveness of the edge termination technique.The epilayer properties of the N-type are 18μm with a doping of 3.5×1015 cm-3.The diodes are fabricated with a floating guard rings edge termination.The on-state voltage is 2.15 V at Jf=350 A·cm-2.