A semiconductor structure includes a silicon substrate, an aluminum nitride layer and a plurality of grading stress buffer layers. The aluminum nitride layer is disposed on the silicon substrate. The grading stress buffer layers are disposed on the aluminum nitride layer. Each grading stress buffer layer includes a grading layer and a transition layer stacked up sequentially. A chemical formula of the grading layer is Al.sub.1-xGa.sub.xN, wherein the x value is increased from one side near the silicon substrate to a side away from the silicon substrate, and 0x1. A chemical formula of the transition layer is the same as the chemical formula of a side surface of the grading layer away from the silicon substrate. The chemical formula of the transition layer of the grading stress buffer layer furthest from the silicon substrate is GaN.

Disclosed are a substrate regeneration method and a regenerated substrate. The substrate regeneration method comprises preparing a substrate having a surface separated from an epitaxial layer. The separated surface includes a convex portion and a concave portion, and the convex portion is comparatively flatter than the concave portion. A crystalline restoration layer is grown on the separated surface. The crystalline restoration layer is grown on the convex portion. Furthermore, a surface roughness improvement layer is grown on the crystalline restoration layer, thereby providing a continuous surface. Accordingly, it is possible to provide a regenerated substrate, which has a flat surface, without using physical polishing or chemical etching technology.

The present disclosure provides a light-emitting device. The light-emitting device comprises a substrate; a light-emitting stack which emits infrared (IR) light on the substrate; and a semiconductor window layer comprising AlGaInP series material disposed between the substrate and the light-emitting stack.

A method of manufacturing a nitride semiconductor element includes dry etching a main surface of a sapphire substrate at a c-plane side thereof, using a mask provided on the main surface, to form a plurality of projections, each having a circular bottom surface; wet etching the sapphire substrate to form an upper part of each projection into a triangular pyramid shape while maintaining the circular bottom surface of the projection; and growing a semiconductor layer made of a nitride semiconductor on a dry etched surface and a wet etched surface of the sapphire substrate.

A light emitting device can include a GaN layer having a multilayer structure that can include an n-type layer, an active layer, and a p-type layer, the GaN layer having a first surface and a second surface; a conductive structure on the first surface of the GaN layer, the conductive structure includes a first electrode in contact with the first surface of the GaN layer, the first electrode is configured to reflect light from the active layer back through the second surface of the GaN layer; and a metal layer including Au, in which the metal layer serves as a first pad; a second electrode on the second surface of the GaN layer; and a second pad on the second electrode, in which a thickness of the second pad is about 0.5 m or higher.

A light emitting device includes a metal support structure comprising Cu; an adhesion structure on the metal support structure and comprising Au; a reflective conductive contact on the adhesion structure; a GaN-based semiconductor structure on the reflective conductive contact, the GaN-based semiconductor structure comprising a first-type GaN layer, an active layer, and a second-type GaN layer; a top interface layer on the GaN-based semiconductor structure and comprising Ti; and a contact pad on the top interface layer and comprising Au, wherein the GaN-based semiconductor structure is less than 1/20 thick of a thickness of the metal support structure.

A light-emitting device comprises a substrate having a top surface and a plurality of patterned units protruding from the top surface; and a light-emitting stack formed on the substrate and having an active layer with a first surface substantially parallel to the top surface, wherein one of the plurality of patterned units comprises a plurality of connecting sides constituting a polygon shape in a top view of the light-emitting device, the one of the plurality of patterned units comprises a vertex and a plurality of inclined surfaces respectively extending from the plurality of connecting sides, the plurality of inclined surfaces commonly join at the vertex in a cross-sectional view of the light-emitting device, the vertex being between the top surface of the substrate and the first surface of the active layer, and six of the plurality of patterned units forms a hexagon in the top view of the light-emitting device.

Disclosed are a light emitting device, a method of manufacturing a light emitting device, a light emitting device package and a lighting system. The light emitting device includes a substrate; a first conductive semiconductor layer on the substrate; an active layer on the first conductive semiconductor layer; a second conductive semiconductor layer on the active layer; a contact layer on the second conductive semiconductor layer; an insulating layer on the contact layer; a first branch electrode electrically connected to the first conductive semiconductor layer; a plurality of first via electrodes connected to the first branch electrode and electrically connected to the first conductive semiconductor layer by passing through the insulating layer; a first pad electrode electrically connected to the first branch electrode; a second pad electrode contacts the contact layer by passing through the insulating layer; a second branch electrode connected to the second pad electrode and disposed on the insulating layer; and a plurality of second via electrodes provided through provided through the insulating layer to electrically connect the second branch electrode to the contact layer.

A light emitting diode chip including a substrate and a light emitting diode element layer is provided. The substrate has a growth surface and a plurality of microstructures on the growth surface. An area of the growth surface occupied by the microstructures is A1 and an area of the growth surface not occupied by the micro-structures is A2, such that A1 and A2 satisfy the relation of 0.1A2/(A1+A2)0.5. The light emitting diode element layer is disposed on the growth surface of the substrate.

A method for producing a semiconductor layer sequence is disclosed. In an embodiment the includes growing a first nitridic semiconductor layer at the growth side of a growth substrate, growing a second nitridic semiconductor layer having at least one opening on the first nitridic semiconductor layer, removing at least pail of the first nitridic semiconductor layer through the at least one opening in the second nitridic semiconductor layer, growing a third nitridic semiconductor layer on the second nitridic semiconductor layer, wherein the third nitridic semiconductor layer covers the at least one opening at least in places in such a way that at least one cavity free of a semiconductor material is present between the growth substrate and a subsequent semiconductor layers and removing the growth substrate.