Graphoepitaxy of Ge on SiO2 by solid-state surface-energy-driven grain growth

Abstract

Solid-state surface-energy-driven grain growth in 30-nm-thick Ge films on SiO2, encapsulated with SiO2, produces a predominance of (110) crystallographic texture in secondary grains several micrometers in diameter. If the SiO2 substrate is patterned with a 0.2-μm period relief grating, ∼10 nm deep, with approximately square-wave profile, many of the secondary grains that form have (100) texture. These grains show a graphoepitaxial orientation with 〈100〉 directions preferentially parallel to the grating axis.