(Invited) Multiscale Modeling of Stress-Mediated Compositional Patterning in SiGe Substrates

Abstract

The ability to scalably fabricate periodic, large-area assemblies of Ge quantum dots on Si or SiGe substrates with high degree of spatial and size uniformity is expected to impact numerous technologies, including optoelectronics and high-density patterned media for data storage. Here, we demonstrate experimentally and study computationally a process in which SiGe substrates are compositionally patterned over large areas using spatially-modulated elastic fields applied by a nano-indenter array. The indenter array is pressed against a SiGe wafer and annealed at high temperatures during which the larger Ge atoms are selectively driven away from areas of compressive stress. To study parametrically the stress patterning process, we develop a computer model that describes atomic diffusion in SiGe as a function of temperature, composition, and stress. The model is used to investigate the impact of various parameters such as indenter shape and size on the compositional distribution.