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.