Interface sharpness during the initial stages of growth of thin, short‐period III–V superlattices

Superlattices composed of III–V heterostructures have established applications in high‐speed electronic and optoelectronic devices. As layer thicknesses are reduced, the role of heterostructure interface sharpness becomes more critical to ensuring high quality two‐dimensional growth. In this work, short‐period (less than 1 nm) superlattices with active layer thicknesses of 31 nm were investigated to assess interface roughness in the initial stages of growth. X‐ray diffraction was used to evaluate interface roughness and to calculate superlattice periodicity. Results suggest that surface roughening by islanding may be promoted by GaAs buffer layers that are 10–100 nm thick. Smoother interfaces were obtained in samples with buffer layers 250 nm and greater.