This investigation reports on the first symmetrically double-delta-doped channel InAlAs/InGaAs/GaAs metamorphic field-effect transistor (MFET). Two types of devices are fabricated as follows. In the fabrication of the first, the gate recessing steps are carried out using nonselective etching solution (phosphoric acid/hydrogen peroxide mixtures). In the fabrication of the second, a pH 5.5 selective succinic acid: ammonia hydrogen peroxide: water wet chemical etching liquid is adopted to form the gate recess. A succinic acid-based solution is found to be a better selective etchant of an InGaAs/InAlAs system than the more commonly used phosphoric acid-based solutions, in terms of the etching selectivity and the smoothness of the etched surface. The etch-stop mechanism is inferred from Auger electron spectroscopy to involve the formation of nonvolatile aluminum oxide, in strong agreement with the X-ray photoelectron spectroscopy spectra. Nearly kink-free current-voltage characteristics are achieved. The assessment of these structures for application in power field-effect transistor devices reveals that high frequency, high transconductance devices are feasible. As far as the authors are aware, this study is the first to compare MFETs that use a nonselective wet gate recess with those that use a selective wet gate recess. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3529237] All rights reserved.