Reaction kinetics of surface silicon hydrides

Abstract

The chemical vapor deposition (CVD) of Si from SiH4 is a complex process involving both gas phase and surface reactions. During CVD, surface silicon hydrides [SiHx(a)] are formed and ultimately decompose to form a Si film. We have investigated the surface decomposition kinetics of SiH3(a), SiH2(a), and SiH(a), formed following the adsorption of atomic hydrogen on Si(111)-(7×7) and Si(100)-(2×1), using static secondary ion mass spectrometry (SSIMS) and temperature programmed desorption (TPD). The kinetic parameters for the decomposition of SiH3(a) are reported for the first time. The decomposition kinetics of SiH2(a) and SiH(a) as measured by SSIMS agree well with previous TPD and isothermal desorption measurements. Correlations between the surface decomposition of SiHx species and the activation energies measured for Si film growth, as well as comparisons with silicon hydride species formed from the adsorption of silanes will be discussed.