Analysis of GaAs Growth Rate Anisotropy in Some CVD Systems

Growth rate anisotropy in the vicinity of singular faces is being analized for GaAs layers deposited in some chemical deposition systems. Classical crystal growth theory conceptions was being used. In accordance with them a linear connection between growth rate component in the direction of the normal to the singular face and the growth step density is shown to accur in the range of angle deviation 20, 10 and 6° from the faces (111)B, (001) and (111)A correspondingly. Step motion velocity has been calculated on the assumption that the atoms reaching the surface may be crystallized either by joining the step in echelon or by joining the interstep surface due to nucleation or normal growth mechanism. The discussion shows the model which takes into consideration the growth owing to nucleation and step echelon motion gives more selfconsistent results.