Deposition and Characterization of Undoped and Boron and Phosphorus Doped ( SixGe1 − x O 2 ) Glass Films

Abstract

Glass films of undoped and boron and phosphorus doped glass films were prepared by plasma enhanced chemical vapor deposition using germane, silane, phosphine, diborane, and oxygen as precursor gas sources with argon as a carrier gas. Film synthesis was carried out at 200°C using a dual‐coil, inductively coupled plasma system. The presence of silane was not necessary to catalyze the decomposition of germane in the plasma environment as required in a strictly thermal environment. The index of refraction of undoped films changes linearly with composition, and deposition rate was nearly constant across all film compositions. Oxide film composition was determined using energy dispersive X‐ray spectroscopy and Auger energy spectroscopy. For undoped films, solid‐phase composition varied linearly with silane gas‐phase composition. For doped compositions, phosphorus mole fraction in the solid phase was up to a factor of two greater than that present in the gas phase. In contrast to this, the quantity of boron incorporated into the solid phase was a factor of five to six less than present in the gas phase. When both dopants were present in the gas phase, the amount of each incorporated into the solid phase was similar to that in the gas phase. © 2000 The Electrochemical Society. All rights reserved.