Growth and microstructure of semimetallic ErAs particles embedded in an In0.53Ga0.47As matrix

We report the growth by molecular beam epitaxy of composite epitaxial materials consisting of layers of semimetallic ErAs particles embedded in an In0.53Ga0.47As matrix. These structures are grown on (100)-oriented semiinsulating InP:Fe substrates at 490DGC. Cross-sectional and plan view transmission electron microscopy images show that the ErAs forms 4 monolayer high islands and range in size from 30 nm x 4 nm to 2 x nm x 2 nm. Epitaxial overgrowth of these islands is possible by first depositing 2.5 nm of In0.52Ga0.48As before overgrowing with 37.5nm of In0.53Ga0.47As. Samples grown without the In0.52Ga0.48As smoothing layer have a much higher surface roughness. An increase in the In0.53Ga0.47As growth rate (and a consequential increase in the III/V flux ratio) is found to enhance the surface morphology of samples grown without In0.52Ga0.48As smoothing layers. The temperature dependence of the surface morphology is also investigated.