Formation of flat monolayer-step-free (110) GaAs surfaces by growth interruption annealing during cleaved-edge epitaxial overgrowth
15 March 2001
We have characterized, by means of atomic force microscopy, the as-grown and subsequently in situ annealed surfaces of 5 nm GaAs lavers grown by molecular beam epitaxy (MBE) on a vacuum-cleaved (110) GaAs surface, and find that a high temperature growth interruption and anneal remarkably improves the surface morphology of the (110) GaAs laver. Interruption of the 490 degreesC epitaxial GaAs growth by a 10 minute anneal at 600 degreesC under an AS(4) overpressure produces an atomically-flat surface free of monolayer step edges over areas measuring several tens of mum on a side. These results suggest that the (110) GaAs surface has much higher stability under annealing conditions than under MBE growth conditions.