Wave function-dependent mobility and suppression of interface roughness scattering in a strained SiGe p-channel field-effect structure

Abstract

The 4 K Hall mobility has been measured in a top-gated, inverted, modulation-doped Si/Si0.8Ge0.2 structure having a Si:B doping layer beneath the alloy. From comparisons with theoretical calculations, we argue that, unlike an ordinary enhancement-mode SiGe p-channel metal–oxide–semiconductor structure, this configuration leads to a decrease of interface roughness scattering with increasing sheet carrier density. We also speculate on the nature of the interface charge observed in these structures at low temperature.

2-D hole gas with two-subband occupation in a strained Ge channel: Scattering mechanisms

“…[12] have shown that a corrugated interface may also lead to scattering from piezoelectric charges and suggest that this may be the reason for the postulation [18] of an apparent high interface charge density in p-Si/SiGe heterostructures [11]. In bulk Si or Ge, no piezoelectricity can be observed due to cubic crystal symmetry.…”

Diffusion thermopower of a p‐type Si/Si1–xGex heterostructure at zero magnetic field

“…In the previous studies [5], it has always been assumed that the deformation potential experienced by the holes in the valence band is identical to that experienced by electrons in the conduction band [17] with a different coupling constant Ξ . This assumption is, in fact, invalid.…”

“…First, the potential barrier at the HS's interface is always assumed to be infinite [2,3], although it is small, thus changes the transport properties of the HS [3,4]. Next, deformation potential scattering limiting the 2D hole mobility is always based on the idea that the holes and the electrons undergo the same deformation potential [5]. This assumption was indicated [4] to be invalid, and the properly derived deformation scattering was found [4] to strongly limit the 2D hole mobility.…”

Two-Dimensional Analytical Threshold Voltage Modelling of Pseudomorphic Si0.8Ge0.2p-Channel MOSFETs

“…3b). This might be attributed to taking account the ground state wave function in our proposed model in this work that affects the short channel devices [24].…”