Abstract: A semiconductor structure and a method for forming the semiconductor structure are provided. The method includes: providing a monocrystalline substrate having an upper surface covered with a masking layer comprising at least one opening exposing the upper surface; filling the opening by epitaxially growing therein a first layer comprising a first Group III-nitride compound; and growing the first layer further above the opening and on the masking layer by epitaxial lateral overgrowth, wherein the at least one opening has a top surface defined by three or more straight edges forming a polygon parallel to the upper surface and oriented in such a way with respect to the crystal lattice of the monocrystalline substrate so as to permit the epitaxial lateral overgrowth of the first layer in a direction perpendicular to at least one of the edges, thereby forming the semiconductor structure as an elongated structure.

Abstract: A semiconductor structure and a method for forming the semiconductor structure are provided. The method includes: providing a monocrystalline substrate having an upper surface covered with a masking layer comprising at least one opening exposing the upper surface; filling the opening by epitaxially growing therein a first layer comprising a first Group III-nitride compound; and growing the first layer further above the opening and on the masking layer by epitaxial lateral overgrowth, wherein the at least one opening has a top surface defined by three or more straight edges forming a polygon parallel to the upper surface and oriented in such a way with respect to the crystal lattice of the monocrystalline substrate so as to permit the epitaxial lateral overgrowth of the first layer in a direction perpendicular to at least one of the edges, thereby forming the semiconductor structure as an elongated structure.