Collect. Czech. Chem. Commun. 1986, 51, 1-16

A quantitative model of epitaxial layers growth from the gas phase with a simultaneous participation of diffusion, adsorption, and chemical reaction

Emerich Erdösa, Jiří Laitnerb, Josef Stejskalc and Přemysl Klímac

a The Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2
b Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6
c Tesla-Popov Research Institute of Radiocommunication, 142 21 Prague 4


For a quantitative description of the epitaxial growth rate of gallium arsenide, a model has been proposed including two rate controlling steps, namely one step of physical nature and the other one of chemical nature. As the step of physical nature, the diffusion of gaseous components between the gas phase and the epitaxial layer surface has been considered, and from the steps of chemical nature the adsorption of gaseous components on the epitaxial layer surface and a heterogenous surface reaction have been taken into account. According to the kind of the chemical rate controlling step, five mechanisms have been proposed, where a one - centre model was used in all cases, i.e. the idea that the rate controlling step takes place under participation of one active centre. For all the mechanisms considered, the pertaining rate equations have been derived, which were confronted with the experimentally found dependences of the growth rate on partial pressures of components in the feed. The results are discussed both from the view point of plausibility of individual mechanisms and from the point of view of their applicability and of the next research direction.