We demonstrate the highly selective etching of AlGaAs photonic crystal (PhC) structures with electron beam (EB) resist masks by using Cl 2/HI/Xe mixed plasma. We found that the Cl2/HI plasma etches the AlGaAs layer while suppressing EB mask etching, and the addition of Xe eliminates damage to the EB mask caused by radicals. With this balanced approach, we achieved a 3-fold increase in the etching selectivity of the etching rate ratio of AlGaAs/resist. Moreover, using these conditions we successfully fabricated an AlGaAs PhC slab with a fine structure and very small air holes that had a radius of 48 nm and a lattice constant of 240 nm.
|ジャーナル||Japanese Journal of Applied Physics, Part 2: Letters|
|出版ステータス||Published - 2006|
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