Gallium nitride based III-V group compound semiconductor device and method of producing the same
A gallium nitride-based III-V Group compound semi-conductor device has a gallium nitride-based III-V Group compound semiconductor layer provided over a substrate, and an ohmic electrode provided in contact with the semiconductor layer. The ohmic electrode is formed of a metallic material, and has been annealed.
1. A gallium nitride-based III-V Group compound semiconductor light-emitting device comprising:
a substrate having a substantially square surface shape, said substrate having first and second major surfaces;
a semiconductor stacked layer structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer provided over said n-type semiconductor layer, said p-type semiconductor layer having a cut-off portion partially exposing a surface of said n-type semiconductor layer;
a first electrode structure provided on the exposed surface of said n-type semiconductor layer;
a second electrode structure provided in electrical contact with said p-type semiconductor layer, and arranged on the same side of the substrate as said first electrode structure, said second electrode structure comprising a light-transmitting electrode layer and provided on a surface of said p-type semiconductor layer, and a bonding pad provided on said light-transmitting electrode layer;
a continuous insulating protective film covering a surface of said light-transmitting electrode layer, having a thickness of from 0.001 μm to 1 μm, exposed between said first electrode structure and said bonding pad, as well as a portion of the exposed surface of said n-type semiconductor layer,
wherein the insulating protective film has a light-transmissivity.
2. The device according to claim 1 , wherein said insulating protective film has a thickness of from 0.001 μm to 10 μm, and includes a silicon oxide, a titanium oxide, an aluminum oxide, or a silicon nitride.
3. The device according to claim 1 , wherein said insulating protective film covers also a portion of the upper surface of said first electrode structure.
4. The device according to claim 1 , wherein said insulating protective film covers also a portion of the upper surface of said bonding pad.
5. The device according to claim 1 , wherein said light-transmitting electrode layer comprises one or more metals selected from gold, nickel, platinum, aluminum, tin, indium, chromium, and titanium.
6. The device according to claim 1 , wherein a portion of the surface of the surface of said p-type semiconductor layer is exposed and said bonding pad is extended thereon.
7. The device according to claim 1 , wherein said first electrode structure is arranged at a first portion corresponding to a first corner portion of said substrate, having a substantially square surface shape.
8. The device according to claim 7 , wherein said bonding pad is arranged at a second portion corresponding to a second corner portion of said substrate, and wherein said first and second corner portions of said substrate are diagonally arranged with respect to the substantially square surface of said substrate.
9. A gallium nitride-based III-V Group compound semiconductor light-emitting device comprising:
a substrate having a substantially square surface shape, said substrate having first and second major surfaces;
a semiconductor stacked layer structure arranged over said first major surface of the substrate, and comprising an n-type gallium nitride-based III-V Group compound semiconductor layer and a p-type gallium nitride-based III-V Group compound semiconductor layer provided over said n-type semiconductor layer, said p-type semiconductor layer having a cut-off portion partially exposing a surface of said n-type semiconductor layer;
a first electrode structure provided on the exposed surface of said n-type semiconductor layer;
a second electrode structure provided in electrical contact with said p-type semiconductor layer, and arranged on the same side of the substrate as said first electrode structure, said second electrode structure comprising a light-transmitting electrode layer and provided on a surface of said p-type semiconductor layer, and a bonding pad provided on said light-transmitting electrode layer;
a continuous insulating protective film covering a surface of said light-transmitting electrode layer, having a thickness of from 0.001 μm to 1 μm, exposed between said first electrode structure and said bonding pad, as well as a portion of the exposed surface of said n-type semiconductor layer,
wherein said insulating protective film has a thickness of from 0.001 μm to 10 μm, in includes a silicon oxide, a titanium oxide, an aluminum oxide, or a silicon nitride.
10. The device according to claim 9 , wherein said insulating protective film covers also a portion of the upper surface of said first electrode structure.
11. The device according to claim 9 , wherein said insulating protective film covers also a portion of the upper surface of said bonding pad.
12. The device according to claim 9 , wherein said light-transmitting electrode layer comprises one or more metals selected from gold, nickel, platinum, aluminum, tin, indium, chromium, and titanium.
13. The device according to claim 9 , wherein a portion of the surface of p-type semiconductor layer is exposed and said bonding pad is extended thereon.
14. The device according to claim 9 , wherein said first electrode structure is arranged at a first portion corresponding to a first corner portion of said substrate, having a substantially square surface shape.
15. The device according to claim 14 , wherein said bonding pad is arranged at a second portion corresponding to a second corner portion of said substrate, and wherein said first and second corner portions of said substrate are diagonally arranged with respect to the substantially square surface of said substrate.