Deposition of GaInAs/GaInAsP MQWs on patterned substrates

It is pointed out that layer thicknesses can be influenced by growing epitaxial material on a substrate patterned with ridges and channels, due to both the differences in growth rates on different crystallographic planes and in the diffusion rates of the species from adjacent low growth-rate planes. Growth rate enhancements have been seen in layers grown on ridges. Thickness variations can also be achieved by growing material through a window held a small distance above the substrate surface. Growth rate reductions have been shown for GaAs/AlGaAs structures grown in this manner. It is noted that these observed variations can be exploited in multi-quantum well (MQW) structures where the emission wavelength depends on the well thickness. This allows the possibility, for example, of single-stage growth of emitter/waveguide structures.<>