Arsenic precipitate accumulation in alternately Si/Be delta-doped GaAs grown by low-temperature molecular beam epitaxy

Abstract

The precipitation of arsenic in alternately [Si]=1.0 x 10(13) cm(-2) and [Be]=1.0 x 10(14) cm(-2) delta-doped GaAs grown at low temperature by molecular beam epitaxy has been studied using transmission electron microscopy. Following annealing at 600, 700 and 800 degrees C, As precipitates were found to form preferentially not only on planes of Si but also on planes of Be. The as-grown and annealed samples were also characterized using secondary ion mass spectroscopy, and the results revealed that the interdiffusion of Si and Be dopants due to annealing was discernible. This is the first observation of As precipitate accumulation on Be delta-doped planes in low-temperature grown GaAs.