1.55 $\mu$m-range vertical cavity surface emitting lasers, manufactured by wafer fusion of heterostuctures grown by solid-source molecular beam epitaxy

The GaAs–InGaAsP heterointerfaces formation have been studied and optimized using a direct intermolecular wafer bonding (fusion)of an active region heterostructure on an InP substrate and distributed Bragg reflector heterostructures on GaAs substrates for the fabrication of hybrid heterostructures of long-wave vertical-cavity surface-emitting lasers (VCSEL). The heterostructures were grown by solid-source molecular beam epitaxy. It was shown that in the case of incomplete removal of oxide films during the preparation of the wafers before fusion and/or the presence of adsorbed water on the wafer surfaces, the fused interface contains a large number of amorphous inclusions, most likely related to the III-group oxides. Optimization of the formation regimes of a buried tunnel junction on the surface of the InP-based heterostructure made it possible to reduce the surface roughness down to 1 nm and to ensure the thickness of the GaAs–InGaAsP fused interface $<$ 5 nm, with no dislocations or other extended defects in the region of the fused heterointerfaces. The 1.55 $\mu$m-range VCSELs fabricated from the hybrid heterostructures created by using the developed technology demonstrate efficient lasing under continuous wave pumping over a wide temperature range, which indicates the high optical quality of the fused heterointerfaces in the VCSEL heterostructure.