Fabrication of InP Submicron Pillars for Two-Dimensional Photonic Crystals by Reactive Ion Etching

We have fabricated periodic arrays of InP pillars for two-dimensional (2D) photonic crystals by reactive ion etching (RIE) with SiCl4/Ar inductively coupled plasma (ICP) and Cl2 electron cyclotron resonance (ECR) plasma chemistry. Prior to the fabrication of the arrays, photonic band structures for electromagnetic waves are calculated theoretically, and photonic band gaps are predicted to appear in the optical wavelength region. Periodic arrays of InP micron pillars with fairly smooth etched surfaces are fabricated by ICP-RIE with SiCl4/Ar. The reflective properties of the arrays have been characterized in the optical wavelength region by Fourier-transformed infrared reflection absorption spectrometry (FTIR-RAS). FTIR-RAS spectra of the arrays exhibit characteristic features such as a blue shift with decreasing period of pillars. In ECR-RIE, we systematically investigate InP etch characteristics as functions of various etching parameters, and successfully fabricate periodic arrays of vertical submicron pillars with smooth surfaces.