A technique for producing epitaxial films on reuseable substrates

Abstract

Using a new technique, which we have named the CLEFT process (cleavage of lateral epitaxial films for transfer), we have grown single‐crystal GaAs films by vapor phase epitaxy (VPE) on reusable GaAs substrates. A carbonized photoresist mask with narrow, widely spaced stripe openings is first deposited on a (110) GaAs substrate. Epitaxial growth initiated within the openings, followed by lateral growth over the mask, produces a continuous single‐crystal GaAs film. The upper surface of the film is bonded to a glass substrate, and the film is then cleaved from the GaAs substrate, leaving the surface of the latter in condition for repeating the procedure. The same GaAs substrate has been used for successive growth of four GaAs films, each about 4 cm², ranging in thickness from 5 to 10 μm. The electrical properties of a CLEFT film were found comparable to those of conventional VPE layers. The CLEFT process should also be applicable to other semiconductors.