Abstract
We have studied the oxygen etching of Ge islands on glass substrates as a new process of controlling their size and density in a tailored range to form nucleation sites for the growth of polycrystalline thin films. Self-assembled crystalline Ge islands were formed by the solid-phase crystallization (SPC) of amorphous Ge thin films on glass substrates. By annealing the samples under a reduced pressure of oxygen above 350°C, Ge islands were etched to form volatile GeO species (oxygen etching). Single-crystalline Ge islands with good crystallinity and controlled in size and density were fabricated on glass substrates by a simple process combining SPC and oxygen etching.