Nitride semiconductor light emitting device
View Patent ↗A nitride semiconductor light emitting device includes a conductive substrate, a first metal layer, a second conductivity-type semiconductor layer, an emission layer, and a first conductivity-type semiconductor layer in this order. The nitride semiconductor light emitting device additionally has an insulating layer covering at least side surfaces of the second conductivity-type semiconductor layer, the emission layer and the first conductivity-type semiconductor layer. A method of manufacturing the same is provided. The nitride semiconductor light emitting device may further include a second metal layer. Thus, a reliable nitride semiconductor light emitting device and a method of manufacturing the same are provided in which short-circuit at the PN junction portion and current leak is reduced as compared with the conventional examples.
1. A nitride semiconductor light emitting device including a conductive substrate formed of a semiconductor material, a first metal layer, a second conductivity-type semiconductor layer, an emission layer, and a first conductivity-type semiconductor layer, in this order,
wherein the nitride semiconductor light emitting device additionally has an insulating layer which covers at least side surfaces of said second conductivity-type semiconductor layer, said emission layer and said first conductivity-type semiconductor layer,
wherein said first metal layer comprises a first surface that is a surface of a second ohmic layer, and a second surface that is disposed opposite the first surface and is a surface of a first ohmic layer,
wherein the first surface of the first metal layer has a first portion facing said second conductivity-type semiconductor layer, and a second portion on which said insulating layer is disposed,
wherein a first portion of a first surface of said second conductivity-type semiconductor layer does not have said insulating layer thereon and is in contact with said first portion of said first surface of said first metal layer, and
wherein a second portion of the first surface of said second conductivity-type semiconductor layer is not in contact with said first surface of said first metal layer, and the insulating layer covers the second portion of said first surface of said second conductivity-type semiconductor layer.
2. The nitride semiconductor light emitting device according to claim 1 , wherein said second portion of said first surface of said second conductivity-type semiconductor layer is 1-50% of the entire first surface of said second conductivity-type semiconductor layer.
3. The nitride semiconductor light emitting device according to claim 1 , wherein said second conductivity-type semiconductor layer, said emission layer and said first conductivity-type semiconductor layer are an inversely tapered structure in the vicinity of an end portion of the device.
4. The nitride semiconductor light emitting device according to claim 1 , wherein that surface of said first conductivity-type semiconductor layer which is opposite to a side in contact with said emission layer has projections and depressions.
5. The nitride semiconductor light emitting device according to claim 1 , wherein the nitride semiconductor light emitting device has a first electrode formed on said first conductivity-type semiconductor layer and a second electrode formed on a surface of said conductive substrate which is opposite to a side in contact with said first metal layer.
6. The nitride semiconductor light emitting device according to claim 1 , wherein said first metal layer includes at least one kind of layers selected from the group consisting of a eutectic bonding layer, a diffusion barrier layer, a reflection layer, and a plating underlying layer.