Heterostructures of InGaAs/InP have been grown selectively through windows in SiO2-masked InP substrates using metalorganic molecular beam epitaxy. The structures show high cathodoluminescence efficiency for window sizes down to 5-mu-m. A significant red shift, consistent with compressive lattice strain, and reduced intensity are observed for smaller features. Anomalous growth is observed near the edges of the windows. Selectively grown InGaAs/InP p-n junctions and bipolar transistors exhibit excellent electrical characteristics after removal of 1-2-mu-m of edge material.