Surface reconstruction as a source of growth steps

The surface reconstruction on the treads of a growing crystal surface may provide the source of growth steps required for the growth to proceed at low supercooling or supersaturation. It is proposed that this mechanism obtains in the growth of those semiconducting materials, including dislocation-free Si and GaAs, for which no evidence for the screw dislocation mechanism has been found. Experiments supporting this proposal are mentioned. © 1977.