Alkyl-trichlorosilane monolayer as ultra-thin insulating film for silicon MIS devices

Abstract

In order to fabricate metal-insulator-semiconductor (MIS) devices with gate insulating films thinner than 5 nm, organic monolayers have been grafted on the native oxide layer of silicon wafer. We demonstrate for the first time that a single monolayer of alkyl-trichlorosilane with a thickness in the range 1.9–2.8 nm allows to fabricate a silicon based MIS device with gate leakage current density as low as 10 -8 A/cm 2 at 5.8 MV/cm, high dielectric breakdown field (12 MV/cm), insulator charge density lower than 10 10 cm -2, and a fast interface state density at mid-gap of the order of 10 11 cm -2eV -1. Moreover, this insulating film is thermally stable up to 450 °C.