Patent ID: 8357558

Claim:
A method of making a semiconductor light-emitting device, the method comprising the steps of: selecting one or more tilt angles for a primary surface of a substrate of a group III nitride semiconductor in order to estimate a direction of piezoelectric polarization in a light-emitting layer; preparing one or more substrates, a primary surface of each substrate comprising the group III nitride semiconductor, the one or more substrates having the one or more selected tilt angles, respectively; growing a quantum well structure for the light-emitting layer, and p- and n-type gallium nitride semiconductor layers in order to prepare one or more substrate products for the selected tilt angles; measuring a photoluminescence spectrum of each substrate product while applying a bias to the substrate product, to determine bias dependence of the photoluminescence spectrum; evaluating a direction of the piezoelectric polarization in the light-emitting layer at the selected tilt angle on the primary surface of each substrate from the determined bias dependence; selecting a plane orientation of a growth substrate by determining which of the primary surface or a back surface of the substrate is to be used for a tilt angle for the semiconductor light-emitting device, the determination being made using the evaluation, the back surface being opposite to the primary surface, and the growth substrate being prepared for making the semiconductor light-emitting device; and forming a semiconductor laminate for the semiconductor light-emitting device on the primary surface of the growth substrate, the primary surface of the growth substrate comprising the group III nitride semiconductor, the tilt angle being defined by an angle between the primary surface of the substrate and the (0001) plane of the group III nitride semiconductor, the semiconductor laminate comprising a first group III nitride semiconductor region, a light-emitting layer, and a second group III nitride semiconductor region, the light-emitting layer being provided between the first group III nitride semiconductor region and the second group III nitride semiconductor region, the light emitting layer comprising a well layer and a barrier layer, each of the well layer and the barrier layer extending along a reference plane, the reference plane tilting with respect to a plane perpendicular to a reference axis, and the reference axis extending in a direction of the c-axis of the group III nitride semiconductor, the well layer comprising a first gallium nitride semiconductor and being strained, the barrier layer comprising a second gallium nitride semiconductor, and the second gallium nitride semiconductor being differing from the first gallium nitride semiconductor, the first group III nitride semiconductor region comprising at least one n-type group III nitride semiconductor layer, and the second group III nitride semiconductor region comprising at least one p-type group III nitride semiconductor layer.