Effect of Strained k . p Deformation Potentials on Hole Inversion-Layer Mobility

Abstract

In the literature dedicated to strained p-type metal-oxide-semiconductor field-effect transistor inversion-layer mobility calculation via a k . p valence-band structure, three key strain-related material parameters, namely, the Bir-Pikus deformation potentials a(upsilon), b, and d, were widespread in magnitude. To improve such large discrepancies, in this paper, we conduct sophisticated calculations on < 110 >/(001) and < 110 >/(110) hole inversion-layer mobility for gigapascal-level uniaxial stresses along each of three crystallographic directions. The screening effect on surface roughness scattering is taken into account. We find that, to affect the calculated hole mobility enhancement, a(upsilon) is weak, b is moderate, and d is strong, particularly for the uniaxial compressive stress along the < 110 > direction. This provides experimental guidelines for an optimal determination of the primary factor, i.e., d, and the secondary factor, i.e., b, with the commonly used values for a(upsilon). The result remains valid for varying surface roughness parameters and models and is supported by recent first-principles and tight-binding calculations. Thus, the strained k . p valence-band structure with the optimized deformation potentials can ensure the accuracy of the calculated transport properties of 2-D hole gas under stress.