Germanium impact on dewetting behavior of silicon-on-insulator

The solid-state dewetting of silicon and germanium thin films is crucial for growing high-performance photoactive
layers and crafting Mie resonator-based antireflective coatings, which are essential components for highly
sensitive photodetectors and third-generation solar cells. This study illustrates the feasibility of engineering the
composition and organization of SiGe nanocrystal on an insulator by combining solid-state dewetting of ultrathin
silicon-on-insulator films (SOI) with epitaxial growth of germanium (Ge). Commencing with an exploration
into the dewetting kinetics of conventional SOI, the investigation pivots towards controlling nanocrystal
composition through germanium growth on SOI during the dewetting process. When germanium is deposited on
SOI, solid-state dewetting prompts the formation of both Ge-rich and Si-rich nanocrystals on the same substrate.
The manipulation of these nanocrystals’ distribution and morphological anisotropy can be achieved by modulating
the thickness of germanium deposited on the SOI substrate. Furthermore, the research demonstrates the
potential transition from SOI dewetting to Ge/SOI dewetting within a single experiment, resulting in the
emergence of Si-rich nanocrystals encircled by Ge-rich counterparts. These experimental findings furnish crucial
insights into comprehending the dewetting mechanisms of Ge/SOI thin films, thereby paving the way for scalable
and sample-specific methodologies in growing photonic nanostructures reliant on SiGe nanocrystals via solidstate
dewetting.