There is great interest in the properties of semiconductor strained- layer superlattices but their practical application is hampered by phenomena involving both point and line defects. In this study the most common line defects, i. e., misfit dislocations, which are concomitant with the misfit strain of the structures of interest, will be used to remove the point defects from the region where the desired devices are to be grown. This will be accomplished with a combination of optically induced dislocation glide and optically induced dislocation climb through the lithographic masks used in the present art to form the devices. The net effect is to getter the point defects at the threading portions of the misfit dislocations after these have been induced to glide to the outer boundaries of the device. As a final solution, the threading dislocations will be used to nucleate dissolution in an etching process to provide trench isolation between the devices. The first target of this process will be the "DX center," which is the major impediment to economically viable AlGaAs HEMT devices, and which has already been found to getter on threading dislocations under optical excitation.
