高性能双栅复合介质ZnO薄膜晶体管的模拟

Analog of High-performance Double-gate Multiple-layer ZnO Thin-film Transistors

提出ZnO薄膜晶体管的一种新型结构——双栅复合介质结构,并利用ATLAS软件对双栅复合介质结构与双栅单介质结构进行仿真。对比分析结果表明,采用复合介质材料可以明显提高器件的电学特性,在相同偏置条件下,双栅复合介质结构饱和电流为5.5×10-5 A,阈值电压为5.83V,亚阈值斜率为0.128V/dec,开关电流比为109;双栅单介质结构相应值分别为1.3×10-7 A、15.5V、0.297V/dec和108。通过晶界势垒高度随VGS变化分析了新型结构阈值电压降低的物理机制。

A novel structure of ZnO thin-film transistor with double-gate and multiple-layer insulator was proposed and simulated with ATLAS software.The new thin-film transistor with multiple-layer insulator has better electrical characteristics,compared with the conventional double-gate one-layer ZnO TFT.Under the same bias condition,double-gate multiple-layer TFT has a saturation current of 5.5×10^-5 A,threshold voltage of 5.83 V,subthreshold slope of0.128V/dec,on-off current ratio of 109;while the four subjects of double-gate one-layer TFT are1.3×10^-7 A,15.50 V,0.297 V/dec,108,respectively.The barrier height variation of grain boundary with VGSchange was analyzed to make clear the physical mechanism of threshold voltage decrease of the novel structure.