Shin Hyeseon, Han Il-Ki, Ko Jae-Hyeon, Jang Moongyu
Department of Nano-Medical Devices Engineering, Hallym University, Gangwon-do, 24252, Korea.
Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul, 02792, Korea.
J Nanosci Nanotechnol. 2018 Sep 1;18(9):6017-6020. doi: 10.1166/jnn.2018.15582.
Hole mobility characteristics were investigated with surface roughness and silicon-on-insulator (SOI) thickness variations to investigate the influence of surface roughness to mobility. The root mean square roughness varied between 0.16, 0.85 and 10.6 nm in 220, 100 and 40 nm thick SOI samples. Hole mobility was measured and analyzed as a function of effective field and temperature with the variations of surface roughness. The hole mobility, determined by transconductance, greatly decreased with the increase of effective field due to the increased surface roughness scattering in 40 nm thick SOI samples. On the other hand, phonon scattering was a dominant mechanism with the increase of temperature, irrespective of surface roughness and SOI thickness. The induced surface roughness of the devices increases the phonon scattering, thereby reducing the electron and hole mobility. The hole mobility decreases with the roughening of the samples, with the increase of temperature due to increased phonon scattering. Therefore, for enhanced mobility, surface scattering and phonon scattering should be controlled even in atomic scale roughened samples.
通过改变表面粗糙度和绝缘体上硅（SOI）厚度来研究空穴迁移率特性，以探究表面粗糙度对迁移率的影响。在厚度为220nm、100nm和40nm的SOI样品中，均方根粗糙度在0.16nm、0.85nm和10.6nm之间变化。随着表面粗糙度的变化，测量并分析了空穴迁移率随有效电场和温度的函数关系。在40nm厚的SOI样品中，由于表面粗糙度散射增加，由跨导确定的空穴迁移率随着有效电场的增加而大幅下降。另一方面，无论表面粗糙度和SOI厚度如何，随着温度升高，声子散射都是主要机制。器件中诱导的表面粗糙度增加了声子散射，从而降低了电子和空穴迁移率。随着样品粗糙度的增加，由于声子散射增加，空穴迁移率随温度升高而降低。因此，为了提高迁移率，即使在原子尺度粗糙的样品中，也应控制表面散射和声子散射。
