CHEMICAL DISSOLUTION InAs, InSb, GaAs AND GaSb IN THE (NH4)2Cr2O7−HBr−H2O ETCHING COMPOSITIONS

Abstract

The features of InAs, InSb, GaAs, and GaSb dissolution in the (NH4)2Cr2O7−HBr−H2O etching compositions have been investigated. The chemical-dynamic polishing in the reproducible hydrodynamic conditions has been used. It was established that the arsenides etching rate changed similarly and achieved the maximum values in the oxidant saturated mixture (22 vol.%). It was found that the antimonides dissolution rate increases when the (NH4)2Cr2O7 concentration is increasing also. It was established that all etching compositions are polishing for InAs and GaAs, and in the case of InSb and GaSb the polishing solutions occupy about 50 % of the investigated concentrated regions. It was shown that the dissolution rate of all crystals decreases to 0,1 μm/min and the quality of the antimonides surface degrades when the H2O concentration is increasing. The substrates dissolution has the diffusion nature. Using metallographic analysis and atomic force microscopy it was confirmed a good quality of InAs, InSb, GaAs and GaSb surface obtained after chemical treatment in the (NH4)2Cr2O7−HBr−H2O polishing solutions.

Keywords

• травильні композиції, хіміко-динамічне полірування, швидкість трав- лення, уявна енергія активації