Photochemical etching of laser‐produced defect centers inn‐ andp‐type Al(Ga,As) heterostructures has been investigated. Inn‐type (Al,Ga)As a decrease of etch rate in the processed zone is observed leading to etch hillocks whereas inp‐type (Al,Ga)As a mesalike structure is formed: the center of the processed zone, 0.5 &mgr;m wide, shows the same etch rate as the unprocessed material whereas the adjacent regions, 10 &mgr;m wide, etch faster. From this etching behavior the following conclusions are made. (1) The laser processing introduces two different defects. DefectAis located in the center of the processed zone, defectBin the adjacent regions. (2) TypeAdefect is inactive in etching ofp‐type material. (3) Combined with luminescence data we assign for this center an energy level 100 meV above the valence band. (4) DefectBis a deep level located in the midgap region.