Evaluation of 3C-SiC/Si residual stress and curvatures along different wafer direction

Abstract

During the heteroepitaxial growth of a thin film on a thick substrate, important stresses arise in the grown material and may influence the physical properties of the film. The residual stresses result in a bending of the substrate/film system. In this work the evaluation of the wafer curvature and the residual stress along different crystallographic directions of the wafer was proposed. Performed by an interferometric optical profilometer, optical microscope and X-ray diffraction analysis, the curvature of the wafer along the [110] and [1−10] wafer directions was observed for hetero-epitaxial Cubic Silicon Carbide (3C-SiC) on Si (001) films. As a consequence of the stress generated during hetero-epitaxy, due to the difference in thermal expansion coefficient and lattice mismatch between the two materials, an asymmetric wafer curvature was observed.