Fabrication of indium phosphide compound photonic crystal by hydrogen iodide/xenon inductively coupled plasma etching

An InP-based photonic crystal with vertical hole (similar to90degrees), smooth sidewall (<10nm) and high uniformity (+/-1%), is successfully fabricated by inductively coupled plasma (ICP) etching using HI-based gas with only an electron beam resist mask. This can be achieved at a low-temperature processing condition because of the high volatility and sidewall protection of the iodide product. The etching condition is optimized to balance the ion and radial effects by controlling the applied bias and the mixture of Xe gas. We can conclude that HI/Xe ICP etching is very useful for the fabrication of active nano/microdevices.