REDUCTION OF BE OUT-DIFFUSION FROM HEAVILY-DOPED GAAS BE LAYERS BY PSEUDOMORPHIC INXGA1-XAS BARRIER LAYERS

The effectiveness of suppressing Be out-diffusion from a Be-doped GaAs layer by strained InGaAs layers using secondary ion mass spectroscopy has been evaluated. The experimental structures consist of an 800 angstrom Be-doped (approximately 1 X 10(19) cm-3) GaAs layer sandwiched between 80 angstrom InxGa1-xAs (x = 0,0.1,0.25) layers. The samples were subjected to rapid thermal annealing (RTA) at 750-degrees-C for 6 min. It is clearly observed that Be diffusion beyond the InGaAs layers is the fastest for the structure with x = 0 and the slowest for the structure with x = 0.25.