Patent ID: 8361885
Filing Date: 2013-01-29
Classification: B82Y,G01N,H01S

Abstract:
1. A method of fabricating group-III nitride semiconductor laser device, the method comprising the steps of: preparing a substrate comprising a hexagonal group-III nitride semiconductor and having a semipolar principal surface; forming a substrate product having a laser structure, an anode electrode, and a cathode electrode, the laser structure including a semiconductor region and the substrate, the semiconductor region being formed on the semipolar principal surface; scribing a first surface of the substrate product in a direction of an a-axis of the hexagonal group-III nitride semiconductor to form first and second scribed grooves; and carrying out breakup of the substrate product by press against a second surface of the substrate product, to form another substrate product and a laser bar, wherein the first surface is a surface opposite to the second surface, wherein the semiconductor region is located between the first surface and the substrate, wherein the laser bar has first and second end faces extending from the first surface to the second surface and made by the breakup, wherein the first and second end faces form a laser cavity of the group-III nitride semiconductor laser device, wherein the anode electrode and the cathode electrode are formed on the laser structure, wherein the semiconductor region includes a first cladding layer comprising a first conductivity type GaN-based semiconductor, a second cladding layer comprising a second conductivity type GaN-based semiconductor, and an active layer being provided between the first cladding layer and the second cladding layer, wherein the first cladding layer, the second cladding layer, and the active layer are arranged along a normal axis to the semipolar principal surface, wherein the active layer includes a GaN-based semiconductor layer, wherein a c-axis of the hexagonal group-III nitride semiconductor of the substrate tilts at an angle ALPHA with respect to the normal axis toward an m-axis of the hexagonal group-III nitride semiconductor, wherein the first and second end faces intersect with an m-n plane defined by the m-axis of the hexagonal group-III nitride semiconductor and the normal axis, wherein the angle ALPHA is in a range of not less than 45° and not more than 80° or in a range of not less than 100° and not more than 135°, wherein the substrate product includes a laser stripe extending above the semipolar principal surface, wherein the laser stripe extends in a direction of a waveguide axis, wherein the waveguide axis extends from one to the other of the first and second end faces, wherein the first scribed groove, one of the laser stripes, and the second scribed groove are arranged in order in a direction of the a-axis of the hexagonal group-III nitride semiconductor, wherein the first scribed groove has an end formed on the first surface, wherein the second scribed groove has an end formed on the first surface, wherein a first distance between the laser stripe and the end of the first scribed groove is smaller than a second distance between the laser stripe and the end of the second scribed groove, and wherein a distance between the end of the first scribed groove and the end of the second scribed groove is smaller than a width of the group-III nitride semiconductor laser device.