An effective gate recess etch process has been applied to AlGaN/GaN modulation-doped field-effect transistors (MODFETs), utilizing low power Cl-2 reactive ion etching. In comparison to GaAs-based materials, GaN shows a greater robustness to ion damage under ion bombardment at very low ion energies (<70 V). It suggests that a viable gate recess etch process is possible. Recessed gate AlGaN/GaN MODFETs with gate to drain breakdown higher than -80 V have been demonstrated with an optimized lower power Cl-2 reactive ion etching.