The alpha-Si/SiGe core/shell nano-wire as highly sensitive bio-sensor

Abstract

Reducing the width of a nano-wire increases its surface to volume ratio, increasing the sensitivity of its conductivity to charges on its surface. Our previous studies have shown that increasing the Ge fraction in Si1-xGex nano-wires improves their sensitivity as bio-sensing. In this work, an alpha-Si/SiGe core/shell nano-wire is successfully fabricated using side-wall spacer method. The maximum sensitivity of a nano-wire bio-sensor with an optimized alpha-Si/SiGe thickness ratio is investigated.