Geometrical and band-structure effects on phonon-limited hole mobility in rectangular cross-sectional germanium nanowires

Abstract

Corner effects on phonon-limited mobility in rectangular silicon nanowire metal-oxide-semiconductor field-effect transistors based on spatially resolved mobility analysis Quantum-confinement effect on holes in silicon nanowires: Relationship between wave function and band structureWe calculated the phonon-limited hole mobility in rectangular cross-sectional [001], [110], [111], and [112]-oriented germanium nanowires, and the hole transport characteristics were investigated. A tight-binding approximation was used for holes, and phonons were described by a valence force field model. Then, scattering probability of holes by phonons was calculated taking account of hole-phonon interaction atomistically, and the linearized Boltzmann's transport equation was solved to calculate the hole mobility at low longitudinal field. The dependence of the hole mobility on nanowire geometry was analyzed in terms of the valence band structure of germanium nanowires, and it was found that the dependence was qualitatively reproduced by considering an average effective mass and the density of states of holes. The calculation revealed that [110] germanium nanowires with large height along the [001] direction show high hole mobility. Germanium nanowires with this geometry are also expected to exhibit high electron mobility in our previous work, and thus they are promising for complementary metal-oxide-semiconductor (CMOS) applications. V C 2014 AIP Publishing LLC. [http://dx.

Analysis of Hall mobility in two-dimensional disordered systems

“…In this section, we discuss the case with medium potential height ∆V using an average effective mass for a large unit cell with potential disorders. An average effective mass m avg of a sheet structure with a cell size of L cell × L cell and periodic boundary conditions can be calculated from its Ek dispersion E(k x , k y ) by [37,38]…”