Octadecyltrichlorosilane monolayers as ultrathin gate insulating films in metal-insulator-semiconductor devices

Abstract

In order to fabricate metal‐insulator‐semiconductor (MIS) devices with gate insulating films thinner than 5.0 nm, organic monolayers have been grafted on the native oxide layer of silicon wafers. We demonstrate that a single monolayer of octadecyltrichlorosilane with a 2.8 nm thickness allows to fabricate a silicon based MIS device with gate current density as low as 10⁻⁸ A/cm² at 5.8 MV/cm, insulator charge density lower than 10¹⁰ cm⁻², fast interface state density of the order of 10¹¹ cm⁻² eV⁻¹, and dielectric breakdown field as high as 12 MV/cm. Moreover, this insulating film is thermally stable up to 450 °C.