Fabrication of Two-Dimensional InP Photonic Band-Gap Crystals by Reactive Ion Etching with Inductively Coupled Plasma

• Published in: Japanese Journal of Applied Physics Vol. 36; no. 12B; pp. 7763 - 7768
• Main Authors: FUJIWARA, Y, KIKUCHI, K, HASHIMOTO, M, HATATE, H, IMAI, T, TAKEDA, Y, NAKANO, H, HONDA, M, TATSUTA, T, TSUJI, O
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01.12.1997
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Optical materials; Optics; Photonic bandgap materials; Physics; Fabrication; Reactive ion etching; Inductively coupled plasma; Photonic crystal; Indium phosphides; Binary compounds; Optical materials; Experimental study
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.36.7763

We fabricated two-dimensional (2D) InP photonic band-gap crystals by reactive ion etching (RIE) with a SiCl 4 /Ar inductively coupled plasma (ICP) chemistry, and characterized their reflective characteristics in the optical wavelength region by Fourier-transformed infrared reflection absorption spectrometry (FTIR-RAS). The photonic band-gap crystals consisted of a periodic array of parallel air rods of circular cross section whose intersections with a perpendicular plane form a triangular lattice in InP substrates. Prior to the fabrication of the periodic array of air rods, the photonic band structure for electromagnetic waves was calculated theoretically in the sample structure and was predicted to appear in the optical wavelength region. In RIE with the SiCl 4 /Ar ICP chemistry, we systematically investigated the InP etch rate and the etch selectivity of InP over SiO 2 as functions of various etching parameters, to fabricate deep air rods with a vertical profile. The effect of the N 2 O addition to the SiCl 4 /Ar ICP chemistry was investigated and it was revealed that the addition of a small amount of N 2 O results in an improvement in the vertical profile with a slight increase in the InP etch rate. The InP etch rate and the etch selectivity of InP over SiO 2 depended strongly on the SiCl 4 flow rate. In FTIR-RAS measurements, characteristic features were observed in the optical wavelength region, depending on the diameter of the air rods. Behaviors of the features were discussed in relation to theoretically calculated densities of states.