Patent ID: 8642366
Filing Date: 2014-02-04
Classification: B82Y,H01S

Abstract:
1. A method for fabricating a group-III nitride semiconductor laser device, comprising the steps of: preparing a substrate product having a substrate and a semiconductor region, the substrate comprising a hexagonal group-III nitride semiconductor and including a semi-polar principal surface, the semiconductor region provided on the semi-polar principal surface and including an active layer; scribing a first surface of the substrate product to form a plurality of scribe marks extending along an a-axis of the hexagonal group-III nitride semiconductor; and forming a laser bar and a substrate product residue from the substrate product with a cleaving system, wherein the cleaving system has a support plate supporting the substrate product and a blade forced down through a second surface opposite to the first surface of the substrate product toward the support plate while the substrate product is being supported by the support plate, the support plate has a front surface, a back surface opposite to the front surface, and a space extending from the front surface to the back surface, the substrate product is placed on the front surface, the space extends in the direction orthogonal to a reference axis extending along the front surface of the support plate and defined by the support plate, the span of the space in the direction orthogonal to the reference axis is longer than the diameter of the first surface, and the step of forming the laser bar and the substrate product residue comprises: fixing the substrate product on the support plate such that an endmost scribe mark among the plurality of scribe marks is located above the space and extends along the space; tilting the support plate at an angle THETA from an m-axis toward a reference plane defined by the direction of travel of the blade and the a-axis in a c-m plane defined by a c-axis and the m-axis of the hexagonal group-III nitride semiconductor while the direction of travel of the blade is being orthogonal to the front surface of the support plate; positioning the blade in the direction orthogonal to the a-axis such that the blade overlaps a plane including an intersection between the endmost scribe mark and the first surface and extending along the direction of travel of the blade; and forcing the blade down through the second surface of the substrate product, wherein a portion of the second surface extends along the a-axis, and the blade is forced down through the portion of the second surface, a c-axis vector indicating the direction of the c-axis tilts at an angle ALPHA from a normal vector of the semi-polar principal surface, the angle ALPHA ranges either from 71 degrees to 79 degrees or from 101 degrees to 109 degrees, the angle THETA ranges from 11 degrees to 19 degrees, the laser bar extends from the first surface to the second surface, and has first and second end faces formed by the separation, the first and second end faces intersect the c-m plane, and the first and second end faces function as a laser cavity of the group-III nitride semiconductor laser device.