Beryllium doping in Ga0.47In0.53As and Al 0.48In0.52As grown by molecular-beam epitaxy

Abstract

Beryllium-doped Ga0.47In0.53As and Al 0.48In0.52As epitaxial layers lattice matched to InP substrates have been grown by molecular-beam epitaxy (MBE). Doping levels as high as 2.5×1019 cm-3 have been achieved for both p-type Ga0.47In0.53As and Al0.48In 0.52As. The maximum carrier concentration is an order of magnitude higher for these Be-doped layers than for those doped with Mn. The carrier concentration varies proportionally with the arrival rate of Be and the sticking coefficient of Be is estimated to be unity. Under our growth conditions, the carrier concentrations in Ga0.47In0.53As and Al 0.48In0.52As layers are identical for the same Be arrival rate. Mobility studies showed that MBE grown Be-doped Ga0.47In 0.53As layers are comparable to the best reported results obtained with liquid-phase epitaxy. When Sn was used as the n-type dopant, both Ga 0.47In0.53As and Al0.48In0.52As p-n junction diodes were fabricated and evaluated.