High Temperature LPCVD of Dielectrics on III-V Substrates for Device Appliclations

Silicon dioxide as well as silicon nitride films deposited on a III-V substrate (InP, GaAs, InGaAs) are obtained in a reduced pressure, air and water cooled CVD reactor, with a rapid thermal heating. Deposition rates as high as 100 Å/sec are obtained for deposition of SiO2 at 700°C and 30 Å/sec for Si3N4 at 800°C. High temperature deposition is thus obtained on a III-V substrate without any surface damage. The layers display excellent structural and electrical properties suited for passivation and MISFET applications. The properties of III-V semiconductor/insulator interfaces can be improved under an in-situ treatment of the substrate with the reactive gases. Interface studies show that both silane and armmonia can be utilized prior to deposition to reduce native oxide of InP.