A semiconductor device and a method for manufacturing the same are disclosed. The method comprises: forming at least one trench in a first semiconductor layer, wherein at least lower portions of respective sidewalls of the trench tilt toward outside of the trench; filling a dielectric material in the trench, thinning the first semiconductor layer so that the first semiconductor layer is recessed with respect to the dielectric material, and epitaxially growing a second semiconductor layer on the first semiconductor layer, wherein the first semiconductor layer and the semiconductor layer comprise different materials from each other. According to embodiments of the disclosure, defects occurring during the heteroepitaxial growth can be effectively suppressed.