Iii-nitride semiconductor laser, and method for fabricating iii-nitride semiconductor laser

Abstract

Provided is a III-nitride semiconductor laser allowing for provision of a low threshold with use of a semipolar plane. A primary surfaceof a semiconductor substrateis inclined at an angle of inclination Ain the range of not less than 50 degrees and not more than 70 degrees toward the a-axis direction of GaN with respect to a reference plane perpendicular to a reference axis Cx along the c-axis direction of GaN. A first cladding layer, an active layer, and a second cladding layerare provided on the primary surfaceof the semiconductor substrate. The well layersof the active layercomprise InGaN. A polarization degree P in the LED mode of emission from the active layer of the semiconductor laser that reaches lasing is not less than −1 and not more than 0.1. The polarization degree P of the III-nitride semiconductor laser is defined by P=(I1−I2)/(I1+I2), using an electric field component I1 in the X1 direction and an electric field component I2 in the X2 direction of light in the LED mode.