DIRECT BONDING OF GAAS FILMS ON SILICON CIRCUITS BY EPITAXIAL LIFTOFF

Epitaxial liftoff has emerged as a viable technique to integrate GaAs with silicon. The technique relies on the separation of a thin epi-GaA s film from its substrate followed by direct bonding of the thin film to a silicon substrate. The silicon substrate has to meet certain plan arity and smoothness conditions in order to obtain high quality bondin g. Unfortunately, processed silicon IC chips do not satisfy these cond itions. In this paper, we report on the results of two different plana rization techniques, plasma etch back and chemical-mechanical polishin g, to integrate GaAs LEDs with silicon circuits using epitaxial liftof f. 4 by 8 arrays of GaAs LEDs have been integrated with silicon driver circuits using plasma etch back. We also have lifted off areas as lar ge as 500 mm2 and bonded them on 5'' device wafers by chemical-mechani cal polishing. This can be essential for mass production of optoelectr onic devices based on epitaxial liftoff.