Process for fabricating an optical device

• Main Authors: KOHL, PAUL ALBERT, OSTERMAYER, FREDERICK WILLIAM, JR, BURTON, RANDOLPH HENRY
• Format: Patent
• Language: English; French; German
• Published: 21.03.1984
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMISTRY; CRYSTAL GROWTH; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; METALLURGY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROMOBJECTS; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

This invention is a process for fabricating optical devices by photoetching geometrical shapes on the surface of an n-type or intrinsic compound semiconductor so as to yield surfaces of optical quality without further processing. The etching process is an electrochemical process where etching is proportional to light intensity. The process involves applying a potential to the compound semiconductor while immersed in an electrolytic solution containing hydrofluoric acid and irradiating the surface to be etched with light in a certain energy range. The distribution of light intensity and ray direction is selected to produce the desired geometrical shape. Particularly advantageous is that the surfaces produced are of optical quality. For example, lenses produced by the etching process exhibit surfaces of optical quality. Further, the process can be carried out on all the lenses on a wafer simultaneously without attention to individual devices. This is highly desirable economically. Also, the lenses produced are integral parts of the light emitting diode.