Controlling Mn Depth Profiles in GaMnAs During High-Temperature Molecular Beam Epitaxial Growth

Mn-doped GaAs thin films were grown at a high substrate temperature of 580 C. During the growth process, the Mn cell temperature was ramped at different rates, resulting in a variety of different Mn concentration depth profile slopes, as measured using dynamic secondary ion mass spectrometry (SIMS). Results show that controlling the Mn deposition rate via temperature during molecular beam epitaxy (MBE) growth can mitigate the effect of Mn atoms diffusing toward the surface. Most importantly, the slope of the Mn concentration as a function of depth inside the sample can be tuned from negative to positive.