The fabrication of Schottky‐gate field‐effect transistors (FET’s) on InGaAs lattice matched to InP is reported. A higher band‐gap interface layer is used to lower the gate leakage to acceptable levels. A technique to deduce the effective saturated electron drift velocity is given, which shows over a factor of 2 higher saturated velocity for InGaAs in comparison to GaAs when used as a FET material.