Band structure anisotropy effects on the ultrafast electron transport in 4H-SiC
- 作者：F.F. Maia Jr. ; E.W.S. Caetano ; J.A.P. da Costa ; V.N. Freire
- 关键词：A. Semiconductors ; D. Electronic transport
- 刊名：Solid State Communications
- 出版年：2008
- 期刊代码：101_00381098
- 类别：ms
- 出版时间：February 2008
- 卷：145
- 期：7-8
- 页码：397-400
- 文件大小：454 K
摘要
We study band structure anisotropy effects on the electron transport transient in 4H-SiC subjected to electric fields parallel and perpendicular to the c-axis direction. Coupled Boltzmann-like energy–momentum balance transport equations are solved numerically within a single equivalent isotropic valley picture in the momentum and energy relaxation time approximation. The electron drift velocity is shown to be higher in the direction parallel to the c-axis than that perpendicular to it, due to the electron effective mass being larger in the former direction. The ultrafast transport regime develops on a subpicosecond scale (
0.2 ps) in both directions, during which an overshoot in the electron drift velocity is observed at 300 K for sufficiently high enough electric fields (> 60 kV/cm).
0.2 ps) in both directions, during which an overshoot in the electron drift velocity is observed at 300 K for sufficiently high enough electric fields (> 60 kV/cm).