Advanced core/multishell germanium/silicon nanowire heterostructures: Morphology and transport

Abstract

A precise level of control over morphology and transport in germanium/silicon core/multishell semiconductor nanowires is attained by interface engineering. Epitaxial in situ growth of such advanced heterostructures is achieved, enabling smooth and crystalline shell quality without ex situ thermal or chemical treatment. Transport simulation predicts such heterostructures with engineered energy band-edges will exhibit enhanced on-currents and transconductances over traditional device designs. Based on this synthesis approach, a 2× improvement in experimental hole mobility, transconductance, and on-currents is demonstrated for heterostructures with smooth surface morphologies compared to those with rough surface morphologies and record normalized on-currents for p-type field effect transistors are achieved.