Kinetics of silicon epitaxy using SiH4 in a rapid thermal chemical vapor deposition reactor

Abstract

The equilibrium hydrogen surface coverage on Si(100) during silicon epitaxy using SiH4 has been measured in a rapid thermal chemical vapor deposition reactor. The hydrogen coverage could be ‘‘frozen out’’ completely on the surface by a rapid cool-down and pump-down of the reactor up to temperatures of ≂575 °C; at temperatures above 575 °C only partial ‘‘freeze-out’’ is achieved. Surface hydrogen was titrated in situ using the reactor as a thermal desorption spectrometer. Epitaxial silicon films were grown in the temperature range 450–700 °C and the film growth kinetics was correlated with the equilibrium hydrogen coverage. The growth mechanism changes from the low-temperature regime, where the surface is hydrogen covered, to the high-temperature regime, where the surface is essentially clean.