A procedure utilizing AlAs etch stop layers coupled with wet etch processes has been developed to accurately control etch depth in the fabrication of uniform parallel quantum wires (QWs) in GaAs/AlGaAs heterostructures. Wires are defined in poly(methylmethacrylate) by electron beam lithography and then transferred into the heterostructure using citric acid/hydrogen peroxide solutions. The use of the etch stop layers permits wires to be accurately patterned by shallow or deep etching and allows for a comparative study of the effect of etch depth on the active dimensions of the wires. It is shown that shallow-etched QWs have active electron channels wider than deep-etched ones due to minimization of sidewall depletion. Also, it is demonstrated that sidewall passivation is achieved with silicon nitride and this aids in making the active electron channel width closer to the physical width of the QWs. Gated QW devices with wires as long as 10 mum have exhibited quantum conductance at 4.2 K which shows that the fabricated wires are damage-free.