Nitride-based light-emitting device and method of manufacturing the same
A nitride-based light-emitting device capable of suppressing reduction of the light output characteristic as well as reduction of the manufacturing yield is provided. This nitride-based light-emitting device comprises a conductive substrate at least containing a single type of metal and a single type of inorganic material having a lower linear expansion coefficient than the metal and a nitride-based semiconductor element layer bonded to the conductive substrate.
1. A method of manufacturing a nitride-based light emitting device, comprising steps of:
forming an isolation layer on a growth substrate and forming a nitride-based semiconductor element layer on said isolation layer;
forming a trench in a separation region of said nitride-based semiconductor element layer;
forming a protective film to cover a side surface and a part of the upper surface of said nitride-based semiconductor element layer exposed by said trench;
forming a p-side electrode having a thickness greater than a thickness of said protective film, on another part of the upper surface, on which no protective film is formed, of said nitride-based semiconductor element layer;
bonding a conductive substrate on said p-side electrode; and
removing said growth substrate located under said isolation layer from said nitride-based semiconductor element layer located on said isolation layer, in a state where said conductive substrate is bonded on said p-side electrode.
2. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said trench has a depth reaching said growth substrate.
3. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said isolation layer is formed on an underlayer formed on said growth substrate.
4. The method of manufacturing a nitride-based light-emitting device according to claim 3 , wherein said underlayer consists of GaN or AlGaN.
5. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said isolation layer consists of InGaN.
6. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said nitride-based semiconductor element layer includes an n-type contact layer in contact with said isolation layer and an n-type cladding layer formed on said n-type contact layer.
7. The method of manufacturing a nitride-based light-emitting device according to claim 6 , wherein said n-type contact layer consists of GaN or AlGaN.
8. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said step of removing said growth substrate from said nitride-based semiconductor element layer includes a step of removing said growth substrate located under said isolation layer from said nitride-based semiconductor element layer located on said isolation layer by delivering a beam having a prescribed wavelength from the side of said growth substrate so that said isolation layer absorbs said beam.
9. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said step of forming said trench includes a step of forming a trench in said nitride-based semiconductor element layer and said isolation layer on said separation region.
10. The method of manufacturing a nitride-based light-emitting device according to claim 1 , wherein said isolation layer has a thickness of about 1 nm to about 1 μm and consists of In x Ga 1-x N (X≧0.2).