GaN-based semiconductor light emitting device and the method for making the same

A method for making a GaN-based semiconductor light emitting device, comprising the steps of:

• growing a GaN-based semiconductor epitaxial region on a primary surface of a wafer composed of a first GaN-based semiconductor;
• growing an active layer on the GaN-based semiconductor epitaxial region;
• growing an electron blocking layer on the active layer;
• and
• growing a contact layer on the electron blocking layer,
• wherein:
• the primary surface of the wafer tilts from a plane normal to a reference axis being the axis [0 0 0 1] or [0 0 0 −1] of the first GaN-based semiconductor toward the m-axis of the first GaN-based semiconductor at a tilt angle of more than or equal to 63 degrees and less than 80 degrees;
• the active layer comprises a second GaN-based semiconductor, the second GaN-based semiconductor containing indium;
• the electron blocking layer comprises a third GaN-based semiconductor, the third GaN-based semiconductor having a bandgap larger than the bandgap of the second GaN-based semiconductor;
• the contact layer comprises a fourth GaN-based semiconductor, the fourth GaN-based semiconductor having a bandgap equal to or less than the bandgap of the third GaN-based semiconductor;
• the first GaN-based semiconductor of the wafer has a dislocation density of 1×107 cm−2 or less.