Parametric analysis of mechanically driven compositional patterning in SiGe substrates

D Kaiser and SM Han and T Sinno, JOURNAL OF APPLIED PHYSICS, 121, 065303 (2017).

DOI: 10.1063/1.4976016

A recently demonstrated approach for creating structured compositional gradients in the near-surface region of SiGe substrates is studied parametrically using a multiresolution coarse-grained lattice kinetic Monte Carlo simulation method. In the "stress patterning" process, a patterned elastic stress field is generated in the SiGe substrate by pressing an array of micro-indenters into it. The stressed substrate is then thermally annealed to drive the atomic diffusion in which the larger Ge atoms are pushed away from the areas of compressive stress. By varying a subset of the parameters that characterize the high- dimensional input space of the process (e. g., indenter spacing, indenter tip shape, and indenter array symmetry) we show that technologically interesting compositional configurations may be readily generated. In particular, we show that it is theoretically possible to generate arrays of welldelineated nanoscale regions of high Ge content surrounded by essentially pure Si. Such configurations may be useful as Ge "quantum dots" that exhibit three-dimensional quantum confinement, which have otherwise been very challenging to create with high degrees of size and spatial uniformity. These simulation results will be instrumental in guiding future experimental demonstrations of stress patterning. Published by AIP Publishing.

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