Fabrication of Micropatterns on Sapphire Substrates via Room-Temperature Selective Homoepitaxial Growth Induced by Electron Beam Irradiation

The surface microstructure of sapphire (α-Al2O3) substrates could be constructed at room temperature via selective sapphire homoepitaxial growth induced by electron beam irradiation in laser molecular beam epitaxy. The films grew homoepitaxially on sapphire (1012) substrates at room temperature only in the region electron-irradiated during film deposition, while amorphous aluminum oxide films grew in the non-irradiated area. The surface micropatterns on sapphire substrates were easily obtained by the selective H3PO4 wet etching of the modified sapphire surface coated with crystalline and amorphous film. The microwall and microgroove could be fabricated on the sapphire substrates at room temperature.