The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have di...The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have difficulty reflecting practical con-ditions.This work demonstrated a multi-fingerβ-Ga_(2)O_(3) MOSFET with a maximum drain current of 0.5 A.Electrical characteris-tics were measured,and the heat dissipation of the device was investigated through infrared images.The relationship between device temperature and time/bias is analyzed.展开更多
A NiO/β-Ga_(2)O_(3) heterojunction-gate field effect transistor(HJ-FET)is fabricated and it_(s)instability mechanisms are exper-imentally investigated under different gate stress voltage(V_(G,s))and stress times(t_(s...A NiO/β-Ga_(2)O_(3) heterojunction-gate field effect transistor(HJ-FET)is fabricated and it_(s)instability mechanisms are exper-imentally investigated under different gate stress voltage(V_(G,s))and stress times(t_(s)).Two different degradation mechanisms of the devices under negative bias stress(NBS)are identified.At low V_(G,s)for a short t_(s),NiO bulk traps trapping/de-trapping elec-trons are responsible for decrease/recovery of the leakage current,respectively.At higher V_(G,s)or long t_(s),the device transfer char-acteristic curves and threshold voltage(V_(TH))are almost permanently negatively shifted.This is because the interface dipoles are almost permanently ionized and neutralize the ionized charges in the space charge region(SCR)across the heterojunction inter-face,resulting in a narrowing SCR.This provides an important theoretical guide to study the reliability of NiO/β-Ga_(2)O_(3) hetero-junction devices in power electronic applications.展开更多
Recently,β-Ga_(2)O_(3),an ultra-wide bandgap semiconductor,has shown great potential to be used in power devices blessed with its unique material properties.For instance,the measured average critical field of the ver...Recently,β-Ga_(2)O_(3),an ultra-wide bandgap semiconductor,has shown great potential to be used in power devices blessed with its unique material properties.For instance,the measured average critical field of the vertical Schottky barrier diode(SBD)based onβ-Ga_(2)O_(3) has reached 5.45 MV/cm,and no device in any material has measured a greater before.However,the high electric field of theβ-Ga_(2)O_(3) SBD makes it challenging to manage the electric field distribution and leakage current.Here,we showβ-Ga_(2)O_(3) junction barrier Schottky diode with NiO p-well floating field rings(FFRs).For the central anode,we filled a circular trench array with NiO to reduce the surface field under the Schottky contact between them to reduce the leakage current of the device.For the anode edge,experimental results have demonstrated that the produced NiO/β-Ga_(2)O_(3) heterojunction FFRs enable the spreading of the depletion region,thereby mitigating the crowding effect of electric fields at the anode edge.Additionally,simulation results indicated that the p-NiO field plate structure designed at the edges of the rings and central anode can further reduce the electric field.This work verified the feasibility of the heterojunction FFRs inβ-Ga_(2)O_(3) devices based on the experimental findings and provided ideas for managing the electric field ofβ-Ga_(2)O_(3) SBD.展开更多
β-Ga_(2)O_(3) possesses a highly promising critical electric field of 8 MV/cm,allowing devices with improved perfor-mance compared with other wide bandgap materials[1,2].The 4-inch wafers grown from a melt and over 1...β-Ga_(2)O_(3) possesses a highly promising critical electric field of 8 MV/cm,allowing devices with improved perfor-mance compared with other wide bandgap materials[1,2].The 4-inch wafers grown from a melt and over 10μm of the epitax-ial layers grown by Halide vapor phase epitaxy(HVPE)with highly controllable doping concentration,are commercially available,paving the way of vertical power devices.Theβ-Ga_(2)O_(3) community has consistently elevated the average criti-cal electric field superior to SiC or GaN,which is suitable for medium/high voltage infrastructures demanding over 900 V[1].Verticalβ-Ga_(2)O_(3) power electronics have made a tremendous progress in recent years,such as various surface/interface engineering,diverse edge termination,quasi-inversion vertical transistor,etc.展开更多
Resistive switching random access memory(RRAM)is one of the most promising candidates with highdensity three-dimensional integration characteristics for nextgeneration nonvolatile memory technology.However,the poor un...Resistive switching random access memory(RRAM)is one of the most promising candidates with highdensity three-dimensional integration characteristics for nextgeneration nonvolatile memory technology.However,the poor uniformity issue caused by the stochastic property of the conductive filament(CF)impedes the large-scale manufacture of RRAM chips.Subulate array has been introduced into the RRAM to minimize the CF randomness,but the methods are cumbersome,expensive,or resolution-limited for large-scale preparation.In this work,Si subulate array(SSA)substrates with different curvature radii prepared by a wafer-scale and nanoscale-controllable method are introduced for RRAM fabrication.The SSA structure,which induces a quasi-single CF or a few CFs formed in the tip region(TR)of the device as evidenced by the high-resolution transmission electron microscopy and energy dispersive spectroscopy characterization,dramatically improves the cycle-to-cycle and device-to-device uniformity.Decreasing the curvature radius of the TR significantly improves the device performance,including switching voltages,high/low resistance states,and retention characteristics.The improved uniformity can be attributed to the enhanced local electric field in the TR.The proposed SSA provides a low-cost,uniform,CMOS-compatible,and nanoscale-controllable optimization strategy for the largescale integration of highly uniform RRAM devices.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)under Grant Nos.61925110,62004184 and 62234007the Key-Area Research and Development Program of Guangdong Province under Grant No.2020B010174002.
文摘The self-heating effect severely limits device performance and reliability.Although some studies have revealed the heat distribution ofβ-Ga_(2)O_(3) MOSFETs under biases,those devices all have small areas and have difficulty reflecting practical con-ditions.This work demonstrated a multi-fingerβ-Ga_(2)O_(3) MOSFET with a maximum drain current of 0.5 A.Electrical characteris-tics were measured,and the heat dissipation of the device was investigated through infrared images.The relationship between device temperature and time/bias is analyzed.
基金supported by the Fundamental Strengthening Program Key Basic Research Project(Grant No.2021-173ZD-057).
文摘A NiO/β-Ga_(2)O_(3) heterojunction-gate field effect transistor(HJ-FET)is fabricated and it_(s)instability mechanisms are exper-imentally investigated under different gate stress voltage(V_(G,s))and stress times(t_(s)).Two different degradation mechanisms of the devices under negative bias stress(NBS)are identified.At low V_(G,s)for a short t_(s),NiO bulk traps trapping/de-trapping elec-trons are responsible for decrease/recovery of the leakage current,respectively.At higher V_(G,s)or long t_(s),the device transfer char-acteristic curves and threshold voltage(V_(TH))are almost permanently negatively shifted.This is because the interface dipoles are almost permanently ionized and neutralize the ionized charges in the space charge region(SCR)across the heterojunction inter-face,resulting in a narrowing SCR.This provides an important theoretical guide to study the reliability of NiO/β-Ga_(2)O_(3) hetero-junction devices in power electronic applications.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61925110,U20A20207,62004184,62004186,and 62234007)the Key-Area Research and Development Program of Guangdong Province (Grant No.2020B010174002)+3 种基金the funding support from University of Science and Technology of China (USTC) (Grant Nos.YD2100002009 and YD2100002010)the Fundamental Research Plan (Grant No.JCKY2020110B010)Collaborative Innovation Program of Hefei Science Center,Chinese Academy of Sciences (Grant No.2022HSC-CIP024)the Opening Project of and the Key Laboratory of Nanodevices and Applications in Suzhou Institute of Nano-Tech and Nano-Bionics of CAS。
文摘Recently,β-Ga_(2)O_(3),an ultra-wide bandgap semiconductor,has shown great potential to be used in power devices blessed with its unique material properties.For instance,the measured average critical field of the vertical Schottky barrier diode(SBD)based onβ-Ga_(2)O_(3) has reached 5.45 MV/cm,and no device in any material has measured a greater before.However,the high electric field of theβ-Ga_(2)O_(3) SBD makes it challenging to manage the electric field distribution and leakage current.Here,we showβ-Ga_(2)O_(3) junction barrier Schottky diode with NiO p-well floating field rings(FFRs).For the central anode,we filled a circular trench array with NiO to reduce the surface field under the Schottky contact between them to reduce the leakage current of the device.For the anode edge,experimental results have demonstrated that the produced NiO/β-Ga_(2)O_(3) heterojunction FFRs enable the spreading of the depletion region,thereby mitigating the crowding effect of electric fields at the anode edge.Additionally,simulation results indicated that the p-NiO field plate structure designed at the edges of the rings and central anode can further reduce the electric field.This work verified the feasibility of the heterojunction FFRs inβ-Ga_(2)O_(3) devices based on the experimental findings and provided ideas for managing the electric field ofβ-Ga_(2)O_(3) SBD.
文摘β-Ga_(2)O_(3) possesses a highly promising critical electric field of 8 MV/cm,allowing devices with improved perfor-mance compared with other wide bandgap materials[1,2].The 4-inch wafers grown from a melt and over 10μm of the epitax-ial layers grown by Halide vapor phase epitaxy(HVPE)with highly controllable doping concentration,are commercially available,paving the way of vertical power devices.Theβ-Ga_(2)O_(3) community has consistently elevated the average criti-cal electric field superior to SiC or GaN,which is suitable for medium/high voltage infrastructures demanding over 900 V[1].Verticalβ-Ga_(2)O_(3) power electronics have made a tremendous progress in recent years,such as various surface/interface engineering,diverse edge termination,quasi-inversion vertical transistor,etc.
基金supported by the National Natural Science Foundation of China(61925110,U20A20207,61821091,62004184,62004186,62171426,51932004,and 51961145110)the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB44000000)+4 种基金the Key Research Program of Frontier Sciences of CAS(QYZDB-SSW-JSC048)the Key-Area Research and Development Program of Guangdong Province(2020B010174002)the Fundamental Research Plan(JCKY2020110B010)the CAS Project for Young Scientists in Basic Research(YSBR-029)the Key Laboratory of Nanodevices and Applications at Suzhou Institute of Nano-Tech and Nano-Bionics of CAS。
基金supported by the National Natural Science Foundation of China(61925110,61821091,51961145110,62004184,and 62004186)the Ministry of Science and Technology of China(2016YFA0201803,2016YFA0203800,and 2017YFB0405603)+3 种基金the Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDY-SSW-JSC001 and QYZDB-SSW-JSC048)the Fundamental Research Funds for the Central Universities(WK2100000014 and WK2100000010)China Postdoctoral Science Foundation(2020M671895 and BX20200320)the Opening Project of Key Laboratory of Microelectronic Devices&Integration Technology,Institute of Microelectronics,Chinese Academy of Sciences。
文摘Resistive switching random access memory(RRAM)is one of the most promising candidates with highdensity three-dimensional integration characteristics for nextgeneration nonvolatile memory technology.However,the poor uniformity issue caused by the stochastic property of the conductive filament(CF)impedes the large-scale manufacture of RRAM chips.Subulate array has been introduced into the RRAM to minimize the CF randomness,but the methods are cumbersome,expensive,or resolution-limited for large-scale preparation.In this work,Si subulate array(SSA)substrates with different curvature radii prepared by a wafer-scale and nanoscale-controllable method are introduced for RRAM fabrication.The SSA structure,which induces a quasi-single CF or a few CFs formed in the tip region(TR)of the device as evidenced by the high-resolution transmission electron microscopy and energy dispersive spectroscopy characterization,dramatically improves the cycle-to-cycle and device-to-device uniformity.Decreasing the curvature radius of the TR significantly improves the device performance,including switching voltages,high/low resistance states,and retention characteristics.The improved uniformity can be attributed to the enhanced local electric field in the TR.The proposed SSA provides a low-cost,uniform,CMOS-compatible,and nanoscale-controllable optimization strategy for the largescale integration of highly uniform RRAM devices.
