An etching method for eaves structures on (001) InP and InP/InGaAsP/InP double heterostructures is presented. The eaves structures are etched by a combination of reactive ion etching and wet chemical etching with a Si3N4 mask. Using this method the vertical and lateral etched depth have been controlled separately by reactive ion etching and wet chemical etching. The fundamental characteristics of the wet chemical etching on a mesa structure, such as etched profiles and etching rates, are studied using H3PO4:H2O:saturated bromine water, HNO3:HBr:H2O and HBr:H2O:saturated bromine water solutions. Influence of the etched profiles and orientations on metallorganic chemical vapor deposition growth behavior is investigated. Using this method 1.55 mu m wavelength high modulation bandwidth semiconductor lasers have been fabricated.