Abstract: Provided is a method for preparing a compound semiconductor substrate. The method includes coating a plurality of spherical balls on a substrate, growing a compound semiconductor epitaxial layer on the substrate coated with the spherical balls while allowing voids to be formed under the spherical balls, and cooling the substrate on which the compound semiconductor epitaxial layer is grown so that the substrate and the compound semiconductor epitaxial layer are self-separated along the voids. The spherical ball treatment can reduce dislocation generations. In addition, because the substrate and the compound semiconductor epitaxial layer are separated through the self-separation, there is no need for laser lift-off process.

Abstract: Provided is a method for preparing a substrate for growing gallium nitride and a gallium nitride substrate. The method includes performing thermal cleaning on a surface of a silicon substrate, forming a silicon nitride (Si3N4) micro-mask on the surface of the silicon substrate in an in situ manner, and growing a gallium nitride layer through epitaxial lateral overgrowth (ELO) using an opening in the micro-mask. According to the method, by improving the typical ELO, it is possible to simplify the method for preparing the substrate for growing gallium nitride and the gallium nitride substrate and reduce process cost.

Abstract: The present invention provides to a gallium nitride (GaN) semiconductor and a method of manufacturing the same, capable of reducing crystal defects caused by a difference in lattice parameters, and minimizing internal residual stress. In particular, since a high-quality GaN thin film is formed on a silicon wafer, manufacturing costs can be reduced by securing high-quality wafers with a large diameter at a low price, and applicability to a variety of devices and circuit can also be improved.

Abstract: The present invention relates to a nitride semiconductor substrate such as gallium nitride substrate and a method for manufacturing the same. The present invention forms a plurality of trenches on a lower surface of a base substrate that are configured to absorb or reduce stresses applied larger when growing a nitride semiconductor film on the base substrate from a central portion of the base substrate towards a peripheral portion. That is, the present invention forms the trenches on the lower surface of the base substrate such that pitches get smaller or widths or depths get larger from the central portion of the base substrate towards the peripheral portion.

Abstract: The present invention relates to a compound semiconductor substrate and a method for manufacturing the same. The present invention provides the manufacturing method which coats spherical balls on a substrate, forms a metal layer between the spherical balls, removes the spherical balls to form openings, and grows a compound semiconductor layer from the openings. According to the present invention, the manufacturing method can be simplified and grow a high quality compound semiconductor layer rapidly, simply and inexpensively, as compared with a conventional ELO (Epitaxial Lateral Overgrowth) method or a method for forming a compound semiconductor layer on a metal layer. And, the metal layer serves as one electrode of a light emitting device and a light reflecting film to provide a light emitting device having reduced power consumption and high light emitting efficiency.

Abstract: A compound semiconductor device and method of manufacturing the same. The method includes coating a plurality of spherical balls on a substrate and selectively growing a compound semiconductor thin film on the substrate on which the spherical balls are coated. The entire process can be simplified and a high-quality compound semiconductor thin film can be grown in a short amount of time in comparison to an epitaxial lateral overgrowth (ELO) method.