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从硅纳米管和纳米线场效应晶体管的结构出发,先用Silvaco公司的TCAD仿真软件模拟出硅纳米管和纳米线的电势分布,然后根据电势分布依次求出两种器件的有效哈密顿量、非平衡格林函数及自能函数和电子浓度,再从电子浓度推导出电流密度与电压方程,并对其进行了分析比较。仿真结果显示,在沟道横截面积相同的情况下,纳米管器件的阈值电压比纳米线器件的高,且随管内外径之差的增加而减小。栅压比较大的情况下,在饱和区纳米管器件比纳米线器件能提供更大的驱动电流。两者在亚阈值区域表现相似,亚阈值摆幅分别为58和57 mV/dec。纳米管器件的饱和电压比纳米线器件的略小,在饱和区纳米管器件的电流更加平直,短沟道效应更不明显。
Starting from the structure of silicon nanotube and nanowire field effect transistor, the potential distributions of silicon nanotube and nanowire are first simulated by TCAD simulation software of Silvaco Company. Then the effective Hamiltonian of the two devices is obtained according to the potential distribution, Non-equilibrium Green’s function and self-function and electron concentration, then derive the current density and voltage equation from the electron concentration, and analyze and compare them. The simulation results show that the threshold voltage of the nanotube device is higher than that of the nanowire device with the same channel cross-sectional area, and decreases with the increase of the difference between the inner and outer diameters of the nanotube. In the case of large gate voltage, the nanotube device can provide more driving current than the nanowire device in the saturation region. Both behave similarly in subthreshold regions with subthreshold swing of 58 and 57 mV / dec, respectively. The saturation voltage of the nanotube device is slightly smaller than that of the nanowire device, and the current of the nanotube device in the saturation region is more straight, and the short channel effect is less obvious.