METHOD FOR LASER SEPARATION OF EPITAXIAL FILM OR LAYER OF EPITAXIAL FILM FROM GROWTH SUBSTRATE OF EPITAXIAL SEMICONDUCTOR STRUCTURE (VERSIONS) Russian patent published in 2012 - IPC H01L21/268 

FIELD: physics.

SUBSTANCE: laser separation method is based on use of selective doping of the substrate and the epitaxial film with small donor and acceptor dopants. During selective doping, concentration of free carriers in the epixatial film and the substrate can significantly differ, and this can lead to a strong difference between optical absorption constants in the infrared region near the region of residual beams where the contribution of optical phonons, free carriers and phonon-plasmon interaction of optical phonons with free carriers into infrared absorption is significant. Corresponding selection of the doping level and frequency of infrared laser radiation can lead to that laser radiation is absorbed mainly in the region of strong doping near the substrate-homoepitaxial film boundary surface. When scanning the substrate-homoepitaxial film boundary surface with a focused laser beam of sufficient power, the semiconductor crystal undergoes thermal decomposition, followed by separation of the homoepitaxial film.

EFFECT: possibility of separating epitaxial films from substrates made from the same crystalline material as the epitaxial film.

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