CONTROL OF AS PRECIPITATION IN LOW-TEMPERATURE GAAS BY ELECTRONIC AND ISOELECTRONIC DELTA-DOPING

Abstract

A systematic study of electronic (Si and Be) and isoelectronic (In and Al) delta-doping effects on the formation of arsenic precipitates in GaAs grown by molecular beam epitaxy (MBE) at low substrate temperature is presented. Both electronic dopant Si and isoelectronic dopant In are found to accumulate As precipitates in postgrowth-annealed samples, while the precipitate accumulation effect is more prominent for Si than In. As precipitate is depleted from regions doped with Be or Al. The results suggest that the electronic property of impurity does not have a direct correlation with the As precipitation process. The effects of doping concentration and postgrowth annealing temperatures are also reported. The ability to control the As precipitates in low-temperature materials should lead to a wide variety of device applications.