Full wafer processing for buried heterostructure lasers

Buried heterostructure lasers are formed by first growing a planar broad area structure, masking with a dielectric stripe and etching of mesas, usually down to the substrate. In the second growth step, current confining layers are grown between the mesas. A successful regrowth process must provide a planarized final surface, which is a particularly important issue when MOVPE is used, since this technique tends to result in mask overgrowth and rough morphology adjacent to the mask edge. In this paper the kinetics of the regrowth has been studied using MOVPE at atmospheric pressure in a Thomas Swan reactor. The contours of InP regrowth were observed by growth interruption at each 0.2 μm of thickness and inserting a 1.5 nm thick lattice matched InGaAs marker layer or by alternating doping between Fe and S at each 0.2 μm of layer growth. The doping or compositional markers were easily stained to show the growth contours