A Kinetic Model for Chemical-Vapor Deposition of Pure-Boron Layers from Diborane

Abstract

In this paper, an analytical model is established to describe the deposition kinetics and the deposition chamber characteristics that determine the deposition rates of PureB-layers grown by chemical-vapor deposition (CVD) from diborane (B2H6) as gas source on a non-rotating silicon wafer. The model takes into consideration the diffusion mechanism of the diborane species through the stationary boundary layer over the wafer, the gas phase processes and the related surface reactions. This model is based on a wide range of input parameters, such as initial diborane partial pressure, total gas flow, axial position on the wafer, deposition temperature, activation energy of PureB deposition from diborane, surface H-coverage and reactor dimensions. The model's predictive capabilities have been verified by experiments performed at 700 ºC in these two different ASM CVD reactors.