Studying Of High Performance MoS₂ Short-Channel Field Effect Transistors And Logic Devices

As the transistors continues to scale down,traditional silicon-based semiconductor devices have gradually reached their physical limits,the short-channel effect has become more and more obvious,and devices are facing bottlenecks in performance and power consumption.Therefore,it is necessary to explore new channel materials and new device structures to solve the current bottleneck of transistor scaling,which becomes increasingly important for the development of future integrated circuits.Due to its atomic layer thickness and no dangling bonds on the surface,two-dimensional（2D）materials are very suitable to the construction of high-performance ultra-short-channel field effect transistors（FETs）,which provides the possibility to solve the important problem of transistor scaling down and has huge application potential in the future of very-large-scale integrated circuits（VLSI）.Based on this,this paper focuses on MoS₂ high-performance short-channel FETs and inverters,which mainly include the following two parts:1.Self-aligned approach for scalable fabrication of sub-10 nm channel length FETs.Combined with our team’s previous method of etching graphene grain boundaries to fabricate ultra-short channel MoS₂ FETs,we report a scalable and stable fabrication method for sub-10 nm MoS₂ FETs.We use hydrogen plasma to selectively etch boundary-aligned BN/graphene heterojunctions to obtain BN/graphene heterojunctions with undercut structures,which are then transferred to monolayer MoS₂.9 nm MoS₂FET fabricated with this new fabrication technique have a high current up to 433μA/μm at V_DS=1 V and 734μA/μm at V_DS=2 V.At the same time,the device has good switching characteristics,its ON/OFF ratio reaches 3×10⁷,and the subthreshold swing（SS）is 120m V/dec.In addition,the device exhibits good short-channel immunity with a drain-induced barrier lower（DIBL）of～50 m V/V.Our statistics on the performance of 12short-channel devices show that our short-channel fabrication method has the advantages of stable and scalable.2.Rail-to-rail MoS₂ inverters.We designed a rail-to-rail MoS₂ inverters by using bilayer MoS₂ and Mo O₃doped monolayer MoS₂ transistors as load and driver transistor,respectively.The bilayer-monolayer inverters（BM-inverters）exhibit a good rail-to-rail operation with a switching threshold voltage V_M≈2 V at V_DD=4 V,a high peak gain of 344 V/V,and a large noise margin NM≈0.98×(V_DD/2).We also realize high noise margin rail-to-rail inverters at V_DD=1,2 V by light doping.Besides,the 3-stage ring oscillators begin to oscillate at V_DD≈5 V,and oscillation frequency reaches 50 k Hz at a V_DD of 12 V.Such a high-performance BM-inverters provides a logic device foundation for building cascaded circuits based on 2D-materils.