Semiconductor light emitting device and method for manufacturing the same
View Patent ↗Certain embodiments provide a method for manufacturing a semiconductor light emitting device, including: providing a first stack film on a first substrate, the first stack film being formed by stacking a p-type nitride semiconductor layer, an active layer having a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer in this order; forming an n-electrode on an upper face of the n-type nitride semiconductor layer; and forming a concave-convex region on the upper face of the n-type nitride semiconductor layer by performing wet etching on the upper face of the n-type nitride semiconductor layer with the use of an alkaline solution, except for a region in which the n-electrode is formed.
1. A semiconductor light emitting device comprising:
a substrate having a first face and a second face opposed to the first face;
a first metal layer having a lower face facing to the first face of the substrate and an upper face;
a stack film including a p-type nitride semiconductor layer having a lower face facing to the upper face of the first metal layer and an upper face, an active layer provided on the upper face of the p-type nitride semiconductor layer and including a multiquantum well structure of a nitride semiconductor, and an n-type nitride semiconductor layer having a lower face facing to the active layer and an upper face;
an n-electrode connected to the n-type nitride semiconductor layer;
a p-electrode provided on the second face of the substrate; and
a concave-convex region provided on the upper face of the n-type nitride semiconductor layer,
the concave-convex region having first concavities and convexities and second concavities and convexities that are smaller than the first concavities and convexities, the first concavities and convexities randomly coexisting with the second concavities and convexities, the first concavities and convexities having height differences of 1 to 3 μm, and the second concavities and convexities having height differences of 300 nm or smaller.
2. The device according to claim 1 , wherein the n-electrode contains one of Pt, Ni, Au, and Ti.
3. The device according to claim 1 , wherein
the stack film includes a tapered shape in cross-section, with an area of a film plane gradually increasing from the n-type nitride semiconductor layer toward the p-type nitride semiconductor layer,
the semiconductor light emitting device further comprises:
a contact electrode provided in a third region of the lower face of the p-type nitride semiconductor layer;
a second metal layer having a lower face facing to the upper face of the first metal layer and an upper face facing to the lower face of the p-type nitride semiconductor layer, the second metal layer covering the contact electrode and being in contact with the contact electrode and the first metal layer, and the second metal layer having a minimum diameter that is smaller than a minimum diameter of the upper face of the first metal layer but is larger than a minimum diameter of the lower face of the p-type nitride semiconductor layer; and
a protection film protecting an outer circumferential region of the upper face of the n-type nitride semiconductor layer, side faces of the stack film, a region of the upper face of the second metal layer other than a region in contact with the p-type nitride semiconductor layer, and a region of the upper face of the first metal layer other than a region in contact with the second metal layer.