SELECTIVE ETCHANT FOR ALUMINUM-ARSENIC AND ALUMINUM-GALLIUM-ARSENIC LAYERS RELATIVE TO GALLIUM-ARSENIC ONE Russian patent published in 2006 - IPC H01L21/306 

FIELD: manufacture of microelectronic and nanoelectronic devices.

SUBSTANCE: selective etchant of AlAs and AlGaAs layers relative to GaAs has iodine I₂ and organic solvent wherein iodine I₂ is dissolved, proportion of mentioned components being as follows, mass percent: iodine, 0.1 - 4; organic solvent, 96 - 99.9. Isopropyl alcohol or acetone can be used as organic solvent. Enhanced selectivity of etching AlAs and AlGaAs layers including those with low Al content (below 40%), as well as their high selectivity relative to InAs and InGaAs are attained at room temperature.

EFFECT: ability of using proposed etchant in nanotechnology for separating upper layers in the order of several single layers.

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