Influence of substrate preparation on fracture properties of InP cantilevers

Abstract

In this study we investigate the influence of the substrate preparation on the mechanical properties of indium phosphide layers used for hetero-micromachining. These layers were grown on silicon by metalorganic vapour-phase epitaxy. Exploiting the etching selectivity of indium phosphide versus silicon we realized freestanding cantilevers oriented in <100> and <110> crystal directions. Fracture-stress measurements revealed that cantilevers fabricated from a layer grown on structured substrates show a lower value compared to those grown on unstructured silicon.