n-channel deep-depletion metal-oxide-semiconductor field-effect transistors fabricated in zone-melting-recrystallized polycrystalline Si films on SiO2

Abstract

n‐channel deep‐depletion mode metal‐oxide‐semiconductor field‐effect transistors (MOSFET’s) have been fabricated in Si films prepared by zone‐melting recrystallization of chemical‐vapor deposited (CVD) polycrystalline Si deposited on SiO₂‐coated Si substrates. The transistors exhibit surface electron mobility in the range of 600–700 cm²/Vs, comparable to values for devices fabricated in single‐crystal Si. Measurements of electron mobility as a function of gate bias voltage indicate that the mobility is nearly constant throughout the depth of the recrystallized Si films. Mobility of 650–700 cm²/Vs at the lower Si‐SiO₂ interface and subthreshold source‐drain leakage current of a few pA/μm (channel width) have been measured.