Growth of distributed feedback/double heterostructure laser structures by hydride vapor phase epitaxy.

A procedure has been developed which allows the reproducible preservation and overgrowth by hydride vapor phase epitaxy of InP first order distributed feedback gratings for double heterostructure (DH) lasers. The process consists of three stages: a short preheat of the grating in a PH sub 3 /argon atmosphere, a low temperature deposition of lambda sub g = 1.1micron quatemary material to planarize the surface, and a preserve in a PH sub 3 /AsH sub 3 /H sub 2 atmosphere during which the substrate heats to the normal growth temperature. This process is followed by a normal deposition of the DH structure. Lasers fabricated from this material exhibit low threshold current densities with good light output.