Growth rate dependence of boron incorporation into BxGa1−xAs layers

This work provides a comprehensive study of the incorporation behavior of B in growing GaAs under molecular beam epitaxy conditions. Structural characterization of superlattices revealed a strong dependence of the BAs growth rate on the GaAs growth rate used. In general, higher GaAs growth rates lead to a higher apparent BAs growth rate, although lower B cell temperatures showed saturation behavior. Each B cell temperature requires a minimum GaAs growth rate for producing smooth films. The B incorporation into single thick layers was found to be reduced to 75-80% compared to superlattice structures. The p-type carrier densities in 1000 nm thick layers were found to be indirectly proportional to the B content. Furthermore, 500 nm thick BxGa1−xAs layers showed significantly lower carrier concentrations, indicating B segregation on the surface during growth of thicker layers.