Selective formation of Ge(100) and (111) on amorphous-insulator at low-temperatures (∼250 °C) is realized through gold-induced- crystallization using a-Ge/Au/SiO2 stacked-structures by combining interface-energy-modulation of substrates. Introduction of thin-Al 2O3 layers (∼7 nm thickness) at a-Ge/Au interfaces enables large-grain (≥20 μm) Ge(111) formation, which is speculated to be due to suppression of random bulk-nucleation and domination of (111)-oriented interface-nucleation on SiO2. To examine this speculation, Al 2O3-covered substrates are employed. This results in formation of Ge(100), due to energetically favorable (100)-oriented interface-nucleation on Al2O3. Consequently, large-grain (≥20 μm) Ge(100) and (111) are achieved on amorphous-insulators at 250 °C. This technique is very useful to realize flexible-electronics.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)