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Title: Investigation of electrochemical etch differences in AlGaAs heterostructures using Cl{sub 2} ion beam assisted etching

A deeply etched, anisotropic 45° and 90° mirror technology is developed for Al{sub x}Ga{sub 1−x}As heterostructures using a Cl{sub 2} ion beam assisted etching system. When etching vertically, using a conductive low-erosion Ni mask, electrochemical etch differences between layers with various Al mole fractions caused nonuniform sidewall profiles not seen in semi-insulating GaAs test samples. These variations, based on alloy composition, were found to be negligible when etching at a 45°. A Si{sub 3}N{sub 4}-Ni etch mask is designed in order to electrically isolate charge buildup caused by the incoming Ar{sup +} ion beam to the Ni layer, preventing conduction to the underlying epitaxial layers. This modification produced smoothly etched facets, up to 8 μm in depth, enabling fabrication of substrate–surface-emitting slab-coupled optical waveguide lasers and other optoelectronic devices.
Authors:
;  [1] ; ;  [2]
  1. Massachusetts Institute of Technology Lincoln Laboratory, 244 Wood St., Lexington, Massachusetts 02420 and Department of Physics and Applied Physics, University of Massachusetts Lowell, 1 University Ave., Lowell, Massachusetts 01854 (United States)
  2. Massachusetts Institute of Technology Lincoln Laboratory, 244 Wood St., Lexington, Massachusetts 02420 (United States)
Publication Date:
OSTI Identifier:
22392137
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTROSCOPY; ALLOYS; ALUMINIUM ARSENIDES; ARGON IONS; CHLORINE; DEPTH; ELECTROCHEMISTRY; EPITAXY; EROSION; ETCHING; FABRICATION; GALLIUM ARSENIDES; ION BEAMS; LAYERS; OPTOELECTRONIC DEVICES; SILICON NITRIDES; SUBSTRATES; X-RAY SPECTROSCOPY