Ridge waveguide multiple quantum well laser diodes in which the ridge heights are predetermined by etch stop layers have been fabricated for the first time in InGaAlAs materials lattice-matched to InP. A 3 nm thick pseudomorphic AlAs layer forms the etch stop layer in these devices and the selective etching was performed by a succinic acid solution that etches InGaAs and InAlAs but not AlAs. With this technique, more reliable and uniform ridge stripe device fabrication is expected.