Isolating GaSb Membranes Grown Metamorphically on GaAs Substrates Using Highly Selective Substrate Removal Etch Processes

• Published in: Journal of electronic materials Vol. 44; no. 5; pp. 1327 - 1331
• Main Authors: Renteria, E. J., Muniz, A. J., Addamane, S. J., Shima, D. M., Hains, C. P., Balakrishnan, G.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.05.2015; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Materials Science; Membranes; Metamorphism; Optical and Electronic Materials; Solid State Physics; Substrates; wet etching; gallium arsenide; substrate removal; Gallium antimonide; epitaxial growth; thin films
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-015-3625-8

The etch rates of NH 4 OH:H 2 O 2 and C 6 H 8 O 7 :H 2 O 2 for GaAs and GaSb have been investigated to develop a selective etch for GaAs substrates and to isolate GaSb epilayers grown on GaAs. The NH 4 OH:H 2 O 2 solution has a greater etch rate differential for the GaSb/GaAs material system than C 6 H 8 O 7 :H 2 O 2 solution. The selectivity of NH 4 OH:H 2 O 2 for GaAs/GaSb under optimized etch conditions has been observed to be as high as 11,000 ± 2000, whereas that of C 6 H 8 O 7 :H 2 O 2 has been measured up to 143 ± 2. The etch contrast has been verified by isolating 2- μ m-thick GaSb epilayers that were grown on GaAs substrates. GaSb membranes were tested and characterized with high- resolution x-ray diffraction and atomic force microscopy.