双栅无掺杂隧穿晶体管特性提升仿真研究

Simulation Study on Enhanced Characteristics of Double Gate Doplingless Tunneling Field-Effect Transistors

对双栅无掺杂型隧穿晶体管(DopingLess TFET,DLTFET)进行了仿真研究。通过对传统无掺杂型器件的载流子分布、电流密度、电势分布及能带图等参数的深入研究,较为全面的了解了此类器件的工作原理。基于DGTFET器件的仿真研究成果,提出了使用两种功函数栅材料构成的隧穿栅(Ф_(TG)=4.0 eV)-控制栅(Ф_(CG)=4.6 eV)-辅助栅(Ф_(AG)=4.0 eV)及异质栅介质共同实现的新型DLTFET器件。含异质栅介质和3种栅材料双栅无掺杂隧穿场效应晶体管(Hetero gate oxide TMDG-DLTFET,HG-TMDG-DLTFET),可有效促进形成更为陡峭的“突变结”。通过仿真验证了该器件较传统DLTFET的有效隧穿分布面积更大,提升了隧穿电流,表现了很好的频率特性。当栅压为1.0 V且漏压为0.5 V时,该器件的开态电流为5.5×10^(−6)A,较传统DLTFET器件的开态电流5.9×10^(−10) A提高了4个数量级;当栅压增至1.5 V时,开态电流达到了2.3×10^(−5)A。

The simulation of DopingLess TFET(DLTFET)is carried out.By research on characteristic parameter of conventional DLTFETs(Co-DLTFET),such as the carrier distribution,current density,potential distribution,and band diagram,the operational principle of this kind of transistors can be comprehensively and systematically understood.Based on the simulation study of DGTFET,a novel design of HG-TMDG-DLTFET is proposed,which is composed of two kinds of work function gate dielectric with tunneling gate(Ф_(TG)=4.0 eV)-control gate(Ф_(CG)=4.6 eV)-auxiliary gate(Ф_(AG)=4.0 eV)and heterogeneous gate dielectric.The dual-gate undoped tunneling field-effect transistor(Hetero gate oxide TMDGDLTFET,HG-TMDG-DLTFET),which contains a heterogeneous gate dielectric and three gate dielectric,can effectively promote the formation of steeper"abrupt junction".The simulation results show that the effective tunneling area of the device is larger than that of the traditional DLTFET,the tunneling current is increased,and the frequency characteristics are very good.When the gate voltage is 1.0 V and drain voltage is 0.5V,the on-state current of HG-TMDG-DLTFET(Ion=5.5×10^(−6)A)is 4 magnitude greater than that of Co-DLTFET(Ion=5.9×10^(−10)A).And when the gate voltage further increase to 1.5 V,the current of this novel device can reach 2.3×10^(−5)A.