The Mechanism Study And Optimization Of Nanoscale Vacuum Channel Device

Scattering-free transport is unattainable in the semiconductor channel,which results in limited electron mobility and increased power dissipations.Meanwhile,among the vacuum gap for carrier transport that is less than the mean free path in air,it is possible to realize the ballistic electron transport in the nanoscale vacuum channel transistors(NVCTs).However,it is still lack of the related research on these novel device structres,especially as the device optimization or modulation mechanism.This thesis is devoted to the fabrication processes and the electrical characteristics of NVCTs.The main factors which influence the emission and modulation characteristics are confirmed.Finally,one functional circuit(inverter)was fabricated including NVCTs,fulfilling a research direction for the further development.The research and the results in this thesis are listed,(1)The drain current is confirmed to be caused from the field emission.Accordingly,an optimized source-drain structure has been designed,resulting in low drive voltage and high drain current.(2)The relationship between the thickness of gate dielectrics(tox)and subthreshold swing(SS)of devices has been simulated.Therefore,devices with high-k gate dielectrics and patterned gate electrodes are fabricated in order to reduce the gate leakage current and improve the modulation performance.(3)Based on vacuum electronics,semiconductor physics and solid-state physics,the mechanism is proposed to provide the theoretical support to the optimization of devices.(4)The performance of inverter including NVCT has been studied.