Effect of H2 on the etch profile of InP/InGaAsP alloys in Cl2/Ar/H2 inductively coupled plasma reactive ion etching chemistries for photonic device fabrication

Abstract

This study demonstrates etch profile engineering of InP, In1−xGaxAs1−yPy, and In0.53Ga0.47As heterostructures results from adding H2 to standard Cl2/Ar inductively coupled plasma-reactive ion etching chemistries. Etch rate curves of bulk InP, In1−xGaxAs1−yPy, and In0.53Ga0.47As show a general parabolic trend as a function of the H2 component of the Cl2/Ar/H2 ratio. Three distinct etching profiles of InP/InGaAsP layers were realized by varying the Cl2/Ar/H2 ratio. Highly anisotropic profiles result for Cl2/Ar/H2 ratios between 2/3/1 and 2/3/2. Waveguiding structures fabricated using this technology are presented with a loss as low as 2 dB/cm. An InP racetrack resonator with a quality factor (Q)>8000 is also presented.

X-ray photoelectron spectroscopy analysis of the effect of temperature upon surface composition of InP etched in Cl2-based inductively coupled plasma

“…A dry-etching process that can produce highly anisotropic profiles, smooth sidewalls, and a smooth etched surface is generally required to fabricate optical waveguides or cavities with minimal optical loss. Inductively coupled plasma (ICP) etching has been widely used in the past for fabricating such InP-based optical devices, and various chlorine- [1][2][3][4][5][6] and HBr-containing [7][8][9] chemistries have been proposed for anisotropic ICP etching of InP. However, the influence of the etched surface composition upon the passivation mechanism is often unknown.…”

Direct measurement of nanoscale sidewall roughness of optical waveguides using an atomic force microscope

“…12 Briefly, PMMA-P͑MMA-MAA͒ bilayer electron-beam resist system was used for the lift-off of NiCr metal mask, which was subsequently utilized for transferring patterns into a SiO 2 layer deposited on the waveguide heterostructures. The re-sulting NiCr/SiO 2 was used as a mask to etch waveguide heterostructures using a Cl 2 /Ar/H 2 gas mixture.…”

InGaAsP/InP based Flattened Ring Resonators with Etched Beam Splitters

“…There have been a few papers that investigated ICP etching of InGaAsP using Cl 2 :H 2 :Ar chemistry [6,7]. We have previously optimized the conditions of this etch to yield smooth and straight sidewalls for deeply etched waveguides, for which low passive loss was demonstrated [8].…”