Characterization of improved InSb interfaces

Abstract

Improved quality surfaces on n-type InSb have been produced using a low-temperature chemical vapor deposition (LTCVD) of SiO2 by pyrolytic decomposition of silane in the presence of oxygen. Preservation of the thin, natural oxide on the InSb surface through a suitable LTCVD process results in a surface state density ≳1010 eV−1 cm−2 and without C–V hysteresis. Confirmation of these results is made by both quasistatic C–V and conductance measurements on MIS structures. Complications introduced by the presence of lateral nonuniformity of the LTCVD oxide and thus in the surface potential, have been accounted for in the observed low density measurements. The presence, chemical identification, and thickness of the natural oxide, both before and after the LTCVD process, has been idependently confirmed by XPS. The apparent oxidation state and resultant electrical properties are identified with changes in LTCVD reactor conditions.