Motivated by the success of graphene research,atomically-thin transition metal dichalcogenide(TMDC)semiconductors are considered as promising field-effect transistor(FET)channel materials for fundamental research and ...Motivated by the success of graphene research,atomically-thin transition metal dichalcogenide(TMDC)semiconductors are considered as promising field-effect transistor(FET)channel materials for fundamental research and potential applications.Bridging atomically-thin TMDC channels to external circuitry using metallic leads is one of the most critical steps towards high-performance devices and cutting-edge materials physics research.展开更多
Metal–semiconductor contacts are crucial components in semiconductor devices.Ultrathin two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated circ...Metal–semiconductor contacts are crucial components in semiconductor devices.Ultrathin two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated circuits.However,their performance is often degraded by conventional metal deposition,which results in a high barrier due to chemical disorder and Fermi-level pinning(FLP).Although,transferring electrodes can address these issues,they are limited in achieving universal transfer of full-class metals due to strong adhesion between pre-deposited metals and substrates.Here,we propose a nanobelt-assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of electrodes.Our contacts obey the Schottky–Mott rule and exhibit a FLP of S=0.99.Both the electron and hole contacts show record-low Schottky barriers of 4.2 and 11.2 meV,respectively.As a demonstration,we construct a doping-free WSe_(2) inverter with these high-performance contacts,which exhibits a static power consumption of only 58 pW.This strategy provides a universal method of electrode preparation for building high-performance post-Moore electronic devices.展开更多
The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on...The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on M （M = Ag,Au,Ta） substrate. Compared with the corresponding free-standing monolayer SnSe, the adsorbed SnSe undergoes a semiconductor- to-metal transition. The potential difference AV indicates that SnSefra contact is the best candidate for the Schottky contact of the three SnSe/M contacts. Two types of current-in-plane （CIP） structure, where a freestanding monolayer SnSe is con- nected to SnSe/M, are identified as the n-type CIP structure in SnSe/Ag contact and p-type CIP structure in SnSe/Au and SnSe/Ta contact. The results can stimulate further investigation for the multifunctional SnSe/metal contact.展开更多
Sub-threshold characteristics of the dual material gate 4H-SiC MESFET （DMGFET） are investigated and the analytical models to describe the drain-induced barrier lowering （DIBL） effect are derived by solving one- an...Sub-threshold characteristics of the dual material gate 4H-SiC MESFET （DMGFET） are investigated and the analytical models to describe the drain-induced barrier lowering （DIBL） effect are derived by solving one- and two- dimensional Poisson＇s equations. Using these models, we calculate the bottom potential of the channel and the threshold voltage shift, which characterize the drain-induced barrier lowering （DIBL） effect. The calculated results reveal that the dual material gate （DMG） structure alleviates the deterioration of the threshold voltage and thus suppresses the DIBL effect due to the introduced step function, which originates from the work function difference of the two gate materials when compared with the conventional single material gate metal-semiconductor field-effect transistor （SMGFET）.展开更多
The purpose of this work is to analyze the electrical properties of the metal–semiconductor contact(MSC)in the framework of the theory of complex systems.The effect of inhomogeneity of the different microstructures:p...The purpose of this work is to analyze the electrical properties of the metal–semiconductor contact(MSC)in the framework of the theory of complex systems.The effect of inhomogeneity of the different microstructures:polycrystalline,monocrystalline,amorphous metal–semiconductor contact surface is investigated,considering a Schottky diode(SD)as a parallel connection of numerous subdiodes.It has been shown that the polycrystallinity of the metal translates a homogeneous contact into a complex system,which consists of parallel connected numerous elementary contacts having different properties and parameters.展开更多
Employing a simple and efficient method of electro-chemical anodization, ZnO nanowire films are fabricated on Zn foil, and an ultraviolet （UV） sensor prototype is formed for investigating the electronic transport th...Employing a simple and efficient method of electro-chemical anodization, ZnO nanowire films are fabricated on Zn foil, and an ultraviolet （UV） sensor prototype is formed for investigating the electronic transport through back-to-back double junctions. The UV （365 nm） responses of surface-contacted ZnO film are provided by I-V measurement, along with the current evolution process by on/off of UV illumination. In this paper, the back-to-back metal-seconductor-metal （M-S-M） model is used to explain the electronic transport of a ZnO nanowire film based structure. A thermionic-field electron emission mechanism is employed to fit and explain the as-observed UV sensitive electronic transport properties of ZnO film with surface-modulation by oxygen and water molecular coverage.展开更多
Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides(TMDCs),have been proven to be excellent channel materials for the next-generation integrated circuit(IC).However,the contact problem betwee...Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides(TMDCs),have been proven to be excellent channel materials for the next-generation integrated circuit(IC).However,the contact problem between 2D TMDCs and metal electrodes has always been one of the main factors restricting their development.In this review,we summarized recent work on 2D TMDCs contact from the perspective of compatible integration with silicon processes and practical application requirements,including the contact performance evaluation indicators,special challenges encountered in 2D TMDCs,and recent optimization methods.Specifically,we sorted out and highlighted the performance indicators of 2D TMDCs contacts,including contact resistance(RC),contact scaling,contact stability,and contact electrical/thermal conductivity.Special challenges of 2D TMDCs and metal contact,such as severe Fermi level pinning,large RC,and difficult doping,are systematically discussed.Furthermore,typical methods for optimizing 2D TMDCs RC,edge contact strategies for scaling contact lengths,and solutions for improving contact stability are reviewed.Based on the current research and problems,the development direction of 2D TMDCs contacts that meet the silicon-based compatible process and application performance requirements is proposed.展开更多
文摘Motivated by the success of graphene research,atomically-thin transition metal dichalcogenide(TMDC)semiconductors are considered as promising field-effect transistor(FET)channel materials for fundamental research and potential applications.Bridging atomically-thin TMDC channels to external circuitry using metallic leads is one of the most critical steps towards high-performance devices and cutting-edge materials physics research.
基金National Natural Science Foundation ofChina,Grant/Award Numbers:51991340,51991342,52225206,92163205,52188101,62322402,62204012,52250398,51972022,52303362,62304019the National KeyResearch and Development Program of China,Grant/Award Numbers:2022YFA1203800,2022YFA1203803,2018YFA0703503,2023YFF1500400,2023YFF1500401+7 种基金the Overseas ExpertiseIntroduction Projects for DisciplineInnovation,Grant/Award Number:B14003the Frontier Cross ResearchProject of the Department of Chinese Academy of Sciences,Grant/AwardNumber:XK2023JSA001the Beijing NovaProgram,Grant/Award Numbers:20220484145,20230484478the YoungElite Scientists sponsorship program,Grant/Award Number:2022QNRC001the Fundamental Research Funds for the Central Universities,Grant/Award Number:FRF-06500207the Interdisciplinary Research Project forYoung Teachers of USTB,Grant/Award Numbers:FRF-TP-22-004C2,FRF-IDRY-21-008,FRF-TP-22-004A1,FRF-IDRY-22-016the State Key Lab for Advanced Metals and Materials,Grant/Award Number:2023-Z05the Special supportfrom the Postdoctoral Science Foundation,Grant/Award Number:8206400173。
文摘Metal–semiconductor contacts are crucial components in semiconductor devices.Ultrathin two-dimensional transition-metal dichalcogenide semiconductors can sustain transistor scaling for next-generation integrated circuits.However,their performance is often degraded by conventional metal deposition,which results in a high barrier due to chemical disorder and Fermi-level pinning(FLP).Although,transferring electrodes can address these issues,they are limited in achieving universal transfer of full-class metals due to strong adhesion between pre-deposited metals and substrates.Here,we propose a nanobelt-assisted transfer strategy that can avoid the adhesion limitation and enables the universal transfer of over 20 different types of electrodes.Our contacts obey the Schottky–Mott rule and exhibit a FLP of S=0.99.Both the electron and hole contacts show record-low Schottky barriers of 4.2 and 11.2 meV,respectively.As a demonstration,we construct a doping-free WSe_(2) inverter with these high-performance contacts,which exhibits a static power consumption of only 58 pW.This strategy provides a universal method of electrode preparation for building high-performance post-Moore electronic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1304518 and U1404109)
文摘The geometries and electronic properties of SnSe/metal contact have been investigated using first-principles calcula- tion. It is found that the geometries of monolayer SnSe were affected slightly when SnSe adsorbs on M （M = Ag,Au,Ta） substrate. Compared with the corresponding free-standing monolayer SnSe, the adsorbed SnSe undergoes a semiconductor- to-metal transition. The potential difference AV indicates that SnSefra contact is the best candidate for the Schottky contact of the three SnSe/M contacts. Two types of current-in-plane （CIP） structure, where a freestanding monolayer SnSe is con- nected to SnSe/M, are identified as the n-type CIP structure in SnSe/Ag contact and p-type CIP structure in SnSe/Au and SnSe/Ta contact. The results can stimulate further investigation for the multifunctional SnSe/metal contact.
基金Project supported by the Pre-research Foundation from the National Ministries and Commissions of China (GrantNo.51308030201)
文摘Sub-threshold characteristics of the dual material gate 4H-SiC MESFET （DMGFET） are investigated and the analytical models to describe the drain-induced barrier lowering （DIBL） effect are derived by solving one- and two- dimensional Poisson＇s equations. Using these models, we calculate the bottom potential of the channel and the threshold voltage shift, which characterize the drain-induced barrier lowering （DIBL） effect. The calculated results reveal that the dual material gate （DMG） structure alleviates the deterioration of the threshold voltage and thus suppresses the DIBL effect due to the introduced step function, which originates from the work function difference of the two gate materials when compared with the conventional single material gate metal-semiconductor field-effect transistor （SMGFET）.
文摘The purpose of this work is to analyze the electrical properties of the metal–semiconductor contact(MSC)in the framework of the theory of complex systems.The effect of inhomogeneity of the different microstructures:polycrystalline,monocrystalline,amorphous metal–semiconductor contact surface is investigated,considering a Schottky diode(SD)as a parallel connection of numerous subdiodes.It has been shown that the polycrystallinity of the metal translates a homogeneous contact into a complex system,which consists of parallel connected numerous elementary contacts having different properties and parameters.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274082 and 51172194)the Excellent Young Scientist Research Award Fund of Shandong Province,China(Grant No.BS2011CL002)
文摘Employing a simple and efficient method of electro-chemical anodization, ZnO nanowire films are fabricated on Zn foil, and an ultraviolet （UV） sensor prototype is formed for investigating the electronic transport through back-to-back double junctions. The UV （365 nm） responses of surface-contacted ZnO film are provided by I-V measurement, along with the current evolution process by on/off of UV illumination. In this paper, the back-to-back metal-seconductor-metal （M-S-M） model is used to explain the electronic transport of a ZnO nanowire film based structure. A thermionic-field electron emission mechanism is employed to fit and explain the as-observed UV sensitive electronic transport properties of ZnO film with surface-modulation by oxygen and water molecular coverage.
基金supported by the National Natural Science Foundation of China(Nos.51991340,51991342,52225206,92163205,52188101,62322402,62204012,52250398,51972022,52303362,and 62304019)the National Key Research and Development Program of China(Nos.2022YFA1203800,2022YFA1203803,and 2018YFA0703503)+6 种基金the Overseas Expertise Introduction Projects for Discipline Innovation(No.B14003)the Frontier Cross Research Project of the Department of Chinese Academy of Sciences(No.XK2023JSA001)the Beijing Nova Program(No.20220484145),the Young Elite Scientists sponsorship program by CAST(No.2022QNRC001)the Fundamental Research Funds for the Central Universities(No.FRF-06500207)the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities,Nos.FRF-TP-22-004C2,FRF-IDRY-21-008,FRF-06500207,FRF-TP-22-004A1,and FRF-IDRY-22-016)the State Key Lab for Advanced Metals and Materials(No.2023-Z05)the Special support from the Postdoctoral Science Foundation(No.8206400173).
文摘Two-dimensional(2D)semiconductors,especially transition metal dichalcogenides(TMDCs),have been proven to be excellent channel materials for the next-generation integrated circuit(IC).However,the contact problem between 2D TMDCs and metal electrodes has always been one of the main factors restricting their development.In this review,we summarized recent work on 2D TMDCs contact from the perspective of compatible integration with silicon processes and practical application requirements,including the contact performance evaluation indicators,special challenges encountered in 2D TMDCs,and recent optimization methods.Specifically,we sorted out and highlighted the performance indicators of 2D TMDCs contacts,including contact resistance(RC),contact scaling,contact stability,and contact electrical/thermal conductivity.Special challenges of 2D TMDCs and metal contact,such as severe Fermi level pinning,large RC,and difficult doping,are systematically discussed.Furthermore,typical methods for optimizing 2D TMDCs RC,edge contact strategies for scaling contact lengths,and solutions for improving contact stability are reviewed.Based on the current research and problems,the development direction of 2D TMDCs contacts that meet the silicon-based compatible process and application performance requirements is proposed.
