Reduction of interface-state density by F2 treatment in a metal-oxide-semiconductor diode prepared from a photochemical vapor deposited SiO2 film

Abstract
A new technique for the reduction of the interface-state density Nss of a metal-oxide-semiconductor (MOS) diode has been developed. The SiO2 film was deposited on Si from Si2 H6 and O2 by direct photochemical vapor deposition (CVD) using vacuum ultraviolet (VUV) light of a D2 lamp. The new technique is a F2 treatment of the Si surface prior to the deposition of SiO2 film. Typically, 5% F2 gas diluted in He was introduced into the CVD chamber at 20 Pa for 5 min under UV light irradiation. The minimum value of the Nss was ∼5×109 cm−2 eV−1 at the Si midgap for the film deposited at 180 °C.