Epitaxial lateral overgrowth of single crystalline diamond with different periodic trench geometries fabricated by laser cutting

Abstract

In this study, the effects of trench geometries on the epitaxial lateral overgrowth (ELO) of diamond are investigated using laser cutting. Compared with the periodic semicircular and square trenches, the triangle trench with a proper width is beneficial to suppress the edge effect and provide a uniform temperature distribution. After optimizing the growth parameters, obvious step-flow mode without non-epitaxy defects is realized on the coalescence region above the trench. The relatively higher lateral growth rate results in the intersection and annihilation of dislocations in the coalescence regions, which can effectively decrease the dislocation density. Finally, a two-step ELO process with complementary triangular trench to further decrease the dislocation density and enhance the growth quality of single crystal diamond.