Simulation Study For A New SOI-Like Bulk Silicon MOSFET

In recent years,SOI(Silicon on Insulator)CMOS(Complementary Metal Oxide Semiconductor)has been widely used in integrated circuit because of its advantages such as high speed,low power consumption,and so on.However,it also has disadvantages,for example,low thermal conductivity and parasitic effect.These all limite the development of SOI devices in deep sub-micron realm.The main idea of SOI-like structure is to improve the disadvantages of SOI device and keep its original advantages.A new SOI-like bulk silicon(SLBS: SOI-Like Bulk Silicon)MOSFET(Metal-Oxide-Semiconductor Field Effect Transistor)is proposed in this paper.The SLBS base on bulk silicon technology.A stepping doping structure of “p/n-/p+” is contained in SLBS.The “n-” layer is fully depleted through the built-in potential of two p-n junctions and acts as buried oxide layer in SOI device.4H-SiC,which has a wide bandgap and good electrical and thermal conductivity,is used as the material of “n-” layer.The fully depleted n-4H-SiC layer which has a wide bandgap can prevent electrons produced in the substrate from being collected by the drain.This lead to a good radiation-hardened characteristics of SLBS device.Then low thermal conductivity,floating body effect and total dose radiation in SOI will be solved because of no buried oxide layer in SLBS device.The design purpose of SLBS structure is to keep the original advantages of both SOI and bulk technology.A simulation for SLBS MOSFET has also been given in this paper.The transfer characteristic and short channel effect is firstly studied and make a comparison with that of SOI device.It can be seen that the proposed structure is likely to show a better DIBL and subthreshold characteristics than SOI during SCEs simulation,except the threshold roll off effect.Self-heating effect(SHE)and single event radiation are then studied.It is discovered that SLBS device eliminate most of the SHE,and reach approximate SEU performance relative to the SOI structure.Hot carrier effect(HCE)and negative bias temperature instability(NBTI)lastly.SLBS device has smaller ΔVt,Gmmax degradation,and gate current than FD SoI device,indicating that the proposed structure is likely to show a better subthreshold characteristics and smaller HCE than FD SOI device.The worst bias condition to hot carrier effect of SLBS was Vgs=1/2Vds.SLBS device also present good NBTI effect than SOI device because of no floating body effect.