This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N...This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N/Ga N HEMT. An RF E-mode device with 2.9-nm-thick Al N barrier layer fabricated by remote plasma oxidation(RPO) treatment at 300℃. The device with a gate length of 0.12-μm has a threshold voltage(Vth) of 0.5 V, a maximum saturation current of 1.16 A/mm, a high Ion/Ioff ratio of 1×108, and a 440-m S/mm peak transconductance. During continuous wave(CW) power testing, the device demonstrates that at 3.6 GHz, a power added efficiency is 61.9% and a power density is 1.38 W/mm, and at 30 GHz, a power added efficiency is 41.6% and a power density is 0.85 W/mm. Furthermore, the RPO treatment improves the mobility of RF E-mode Al N/Ga N HEMT. All results show that the RPO processing method has good applicability to scaling ultrathin barrier E-mode Al N/Ga N HEMT for 5G compliable frequency ranging from sub-6 GHz to Ka-band.展开更多
Power electronic devices are of great importance in modern society.After decades of development,Si power devices have approached their material limits with only incremental improvements and large conversion losses.As ...Power electronic devices are of great importance in modern society.After decades of development,Si power devices have approached their material limits with only incremental improvements and large conversion losses.As the demand for electronic components with high efficiency dramatically increasing,new materials are needed for power device fabrication.Betaphase gallium oxide,an ultra-wide bandgap semiconductor,has been considered as a promising candidate,and variousβ-Ga_(2)O_(3)power devices with high breakdown voltages have been demonstrated.However,the realization of enhancement-mode(E-mode)β-Ga_(2)O_(3)field-effect transistors(FETs)is still challenging,which is a critical problem for a myriad of power electronic applications.Recently,researchers have made some progress on E-modeβ-Ga_(2)O_(3)FETs via various methods,and several novel structures have been fabricated.This article gives a review of the material growth,devices and properties of these E-modeβ-Ga_(2)O_(3)FETs.The key challenges and future directions in E-modeβ-Ga_(2)O_(3)FETs are also discussed.展开更多
A novel enhancement-mode AlGaN/GaN high electron mobility transistor(HEMT) is proposed and studied.Specifically,several split floating gates(FGs) with negative charges are inserted to the conventional MIS structur...A novel enhancement-mode AlGaN/GaN high electron mobility transistor(HEMT) is proposed and studied.Specifically,several split floating gates(FGs) with negative charges are inserted to the conventional MIS structure.The simulation results revealed that the V_(th) decreases with the increase of polarization sheet charge density and the tunnel dielectric(between FGs and AlGaN) thickness,while it increases with the increase of FGs sheet charge density and blocking dielectric(between FGs and control gate) thickness.In the case of the same gate length,the V_(th) will left shift with decreasing FG length.More interestingly,the split FGs could significantly reduce the device failure probability in comparison with the single large area FG structure.展开更多
The threshold voltage(V_(th))of the p-channel metal-oxide-semiconductor field-effect transistors(MOSFETs)is investigated via Silvaco-Atlas simulations.The main factors which influence the threshold voltage of p-channe...The threshold voltage(V_(th))of the p-channel metal-oxide-semiconductor field-effect transistors(MOSFETs)is investigated via Silvaco-Atlas simulations.The main factors which influence the threshold voltage of p-channel GaN MOSFETs are barrier heightΦ_(1,p),polarization charge density σ_(b),and equivalent unite capacitance C_(oc).It is found that the thinner thickness of p-GaN layer and oxide layer will acquire the more negative threshold voltage V_(th),and threshold voltage|V_(th)|increases with the reduction in p-GaN doping concentration and the work-function of gate metal.Meanwhile,the increase in gate dielectric relative permittivity may cause the increase in threshold voltage|V_(th)|.Additionally,the parameter influencing output current most is the p-GaN doping concentration,and the maximum current density is 9.5 mA/mm with p-type doping concentration of 9.5×10^(16) cm^(-3) at VGS=-12 V and VDS=-10 V.展开更多
Although In2O3 nanofibers (NFs) are well-known candidates as active materials for next-generation, low-cost electronics, these NF based devices still suffer from high leakage current, insufficient on-off current rat...Although In2O3 nanofibers (NFs) are well-known candidates as active materials for next-generation, low-cost electronics, these NF based devices still suffer from high leakage current, insufficient on-off current ratios (Ion/Ioff), and large, negative threshold voltages (VTH), leading to poor device performance, parasitic energy consumption, and rather complicated circuit design. Here, instead of the conventional surface modification of In2O3 NFs, we present a one-step electrospinning process (i.e., without hot-press) to obtain controllable Mg-doped In2O3 NF networks to achieve high-performance enhancement-mode thin-film transistors (TFTs). By simply adjusting the Mg doping concentration, the device performance can be manipulated precisely. For the optimal doping concentration of 2 mol%, the devices exhibit a small VTH (3.2 V), high saturation current (1.1 × 10^-4 A), large on/off current ratio (〉 10^8), and respectable peak carrier mobility (2.04 cm2/(V.s)), corresponding to one of the best device performances among all 1D metal-oxide NFs based devices reported so far. When high-K HfOx thin films are employed as the gate dielectric, their electron mobility and VTH can be further improved to 5.30 cm^2/(V.s) and 0.9 V, respectivel), which demonstrates the promising prospect of these Mg-doped In2O3 NF networks for high- performance, large-scale, and low-power electronics.展开更多
The past decades have witnessed a tremendous development of GaN-based power electronic devices grown on Si substrate.This article provides a concise introduction,review,and outlook of the research developments of GaN-...The past decades have witnessed a tremendous development of GaN-based power electronic devices grown on Si substrate.This article provides a concise introduction,review,and outlook of the research developments of GaN-on-Si power device technology.The comprehensive review has discussed the crucial issues in the state-of-the-art device technology based on both GaN materials epitaxy including stress control and point defects study,and device fabrication including normally offsolutions like Cascode,trench MIS-gate,and p-GaN gate.Device reliability and other common fabrication issues in GaN high electron mobility transistors(HEMTs)are also discussed.Lastly,we give an outlook on the GaN-on-Si power devices from two aspects,namely high frequency,and high power GaN ICs,and GaN vertical power devices.展开更多
基金Project supported by the Fundamental Research Funds for the National Key Research and Development Program, China (Grant No. 2020YFB1807403)the National Natural Science Foundation of China (Grant Nos. 62174125, 62188102, and 62131014)。
文摘This paper reports a low-damage interface treatment process for Al N/Ga N high electron mobility transistor(HEMT)and demonstrates the excellent power characteristics of radio-frequency(RF) enhancementmode(E-mode) Al N/Ga N HEMT. An RF E-mode device with 2.9-nm-thick Al N barrier layer fabricated by remote plasma oxidation(RPO) treatment at 300℃. The device with a gate length of 0.12-μm has a threshold voltage(Vth) of 0.5 V, a maximum saturation current of 1.16 A/mm, a high Ion/Ioff ratio of 1×108, and a 440-m S/mm peak transconductance. During continuous wave(CW) power testing, the device demonstrates that at 3.6 GHz, a power added efficiency is 61.9% and a power density is 1.38 W/mm, and at 30 GHz, a power added efficiency is 41.6% and a power density is 0.85 W/mm. Furthermore, the RPO treatment improves the mobility of RF E-mode Al N/Ga N HEMT. All results show that the RPO processing method has good applicability to scaling ultrathin barrier E-mode Al N/Ga N HEMT for 5G compliable frequency ranging from sub-6 GHz to Ka-band.
基金supported in part by the National Basic Research Program of China(Grant No.2021YFB3600202)Key Laboratory Construction Project of Nanchang(Grant No.2020-NCZDSY-008)the Suzhou Science and Technology Foundation(Grant No.SYG202027)。
文摘Power electronic devices are of great importance in modern society.After decades of development,Si power devices have approached their material limits with only incremental improvements and large conversion losses.As the demand for electronic components with high efficiency dramatically increasing,new materials are needed for power device fabrication.Betaphase gallium oxide,an ultra-wide bandgap semiconductor,has been considered as a promising candidate,and variousβ-Ga_(2)O_(3)power devices with high breakdown voltages have been demonstrated.However,the realization of enhancement-mode(E-mode)β-Ga_(2)O_(3)field-effect transistors(FETs)is still challenging,which is a critical problem for a myriad of power electronic applications.Recently,researchers have made some progress on E-modeβ-Ga_(2)O_(3)FETs via various methods,and several novel structures have been fabricated.This article gives a review of the material growth,devices and properties of these E-modeβ-Ga_(2)O_(3)FETs.The key challenges and future directions in E-modeβ-Ga_(2)O_(3)FETs are also discussed.
基金Project supported by“Efficient and Energy-Saving GaN on Si Power Devices”Research Fund(Grant No.KQCX20140522151322946)the Research Fund of the Third Generation Semiconductor Key Laboratory of Shenzhen,China(Grant No.ZDSYS20140509142721434)+1 种基金the“Key Technology Research of GaN on Si Power Devices”Research Fund(Grant No.JSGG20140729145956266)the“Research of Low Cost Fabrication of GaN Power Devices and System Integration”Research Fund(Grant No.JCYJ201602261926390)
文摘A novel enhancement-mode AlGaN/GaN high electron mobility transistor(HEMT) is proposed and studied.Specifically,several split floating gates(FGs) with negative charges are inserted to the conventional MIS structure.The simulation results revealed that the V_(th) decreases with the increase of polarization sheet charge density and the tunnel dielectric(between FGs and AlGaN) thickness,while it increases with the increase of FGs sheet charge density and blocking dielectric(between FGs and control gate) thickness.In the case of the same gate length,the V_(th) will left shift with decreasing FG length.More interestingly,the split FGs could significantly reduce the device failure probability in comparison with the single large area FG structure.
基金Project supported by the Key-Area Research and Development Program of Guangdong Province,China(Grant Nos.2020B010174001 and 2020B010171002)the Ningbo Science and Technology Innovation Program 2025(Grant No.2019B10123)the National Natural Science Foundation of China(Grant No.62074122).
文摘The threshold voltage(V_(th))of the p-channel metal-oxide-semiconductor field-effect transistors(MOSFETs)is investigated via Silvaco-Atlas simulations.The main factors which influence the threshold voltage of p-channel GaN MOSFETs are barrier heightΦ_(1,p),polarization charge density σ_(b),and equivalent unite capacitance C_(oc).It is found that the thinner thickness of p-GaN layer and oxide layer will acquire the more negative threshold voltage V_(th),and threshold voltage|V_(th)|increases with the reduction in p-GaN doping concentration and the work-function of gate metal.Meanwhile,the increase in gate dielectric relative permittivity may cause the increase in threshold voltage|V_(th)|.Additionally,the parameter influencing output current most is the p-GaN doping concentration,and the maximum current density is 9.5 mA/mm with p-type doping concentration of 9.5×10^(16) cm^(-3) at VGS=-12 V and VDS=-10 V.
基金The work was financially supported by the National Natural Science Foundation of China (Nos. 51402160, 51302154, and 51672229), the General Research Fund of the Research Grants Council of Hong Kong, China (No. CityU 11275916), the Natural Science Foundation of Shandong Province, China (No. ZR2014EMQ011), the Taishan Scholar Program of Shandong Province, China, the Science Technology, and Innovation Committee of Shenzhen Municipality (No. JCYJ20160229165240684), and was supported by a grant from the Shenzhen Research Institute, City University of Hong Kong. The work was also supported by National Demonstration Center for Experimental Applied Physics Education (Qingdao University).
文摘Although In2O3 nanofibers (NFs) are well-known candidates as active materials for next-generation, low-cost electronics, these NF based devices still suffer from high leakage current, insufficient on-off current ratios (Ion/Ioff), and large, negative threshold voltages (VTH), leading to poor device performance, parasitic energy consumption, and rather complicated circuit design. Here, instead of the conventional surface modification of In2O3 NFs, we present a one-step electrospinning process (i.e., without hot-press) to obtain controllable Mg-doped In2O3 NF networks to achieve high-performance enhancement-mode thin-film transistors (TFTs). By simply adjusting the Mg doping concentration, the device performance can be manipulated precisely. For the optimal doping concentration of 2 mol%, the devices exhibit a small VTH (3.2 V), high saturation current (1.1 × 10^-4 A), large on/off current ratio (〉 10^8), and respectable peak carrier mobility (2.04 cm2/(V.s)), corresponding to one of the best device performances among all 1D metal-oxide NFs based devices reported so far. When high-K HfOx thin films are employed as the gate dielectric, their electron mobility and VTH can be further improved to 5.30 cm^2/(V.s) and 0.9 V, respectivel), which demonstrates the promising prospect of these Mg-doped In2O3 NF networks for high- performance, large-scale, and low-power electronics.
基金This work was supported by the National Natural Science Foundation of China(Grants No.62174174,61775230,61804162,61874131,62074158,U1601210,61874114,61922001,11634002,61521004,and 61927806)Guangdong Province Key-Area Research and Development Program(Grants No.2019B010130001,2019B090917005,2019B090904002,2019B090909004,2020B010174003,and 2020B010174004)+1 种基金the National Key Research and Development Program of China(Grants No.2016YFB0400100 and 2017YFB0402800)the Science Challenge Project(Grant No.TZ2018003).
文摘The past decades have witnessed a tremendous development of GaN-based power electronic devices grown on Si substrate.This article provides a concise introduction,review,and outlook of the research developments of GaN-on-Si power device technology.The comprehensive review has discussed the crucial issues in the state-of-the-art device technology based on both GaN materials epitaxy including stress control and point defects study,and device fabrication including normally offsolutions like Cascode,trench MIS-gate,and p-GaN gate.Device reliability and other common fabrication issues in GaN high electron mobility transistors(HEMTs)are also discussed.Lastly,we give an outlook on the GaN-on-Si power devices from two aspects,namely high frequency,and high power GaN ICs,and GaN vertical power devices.