Formation of 0.5 μm-period GaAs network structures for two-dimensional photonic crystals by selective area metal-organic vapor phase epitaxy

We report on a novel fabrication method of air-hole-type semiconductor two-dimensional photonic crystals (2D PCs) by selective area metal-organic vapor phase epitaxy (SA-MOVPE). The PC structures are formed on GaAs(111)B substrates with a triangular lattice array of hexagonally shaped silicon-nitride (SiN_x) masks. The periods of the triangular lattice are 10 μm, 2 μm, 1 μm and 0.5 μm. GaAs growth is carried out by conventional MOVPE and flow-rate modulation epitaxy (FME) with trimethylgallium (TMGa) and arsine (AsH ₃). By optimizing growth conditions, we can obtain uniform hexagonal network structures with a 0.5 μm-period and a 0.28 μm-height under low As coverage and low Ga supply i.e. low growth rate. Therefore, the results indicate that the formation of hexagonal network structures by SA-MOVPE is very useful to realize air-hole-type semiconductor 2D PCs