Semiconductor light emitting device
View Patent ↗According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer, a light emitting layer, a dielectric layer, a first electrode, a second electrode and a support substrate. The first layer has a first and second surface. The second layer is provided on a side of the second surface of the first layer. The emitting layer is provided between the first and the second layer. The dielectric layer contacts the second surface and has a refractive index lower than that of the first layer. The first electrode includes a first and second portion. The first portion contacts the second surface and provided adjacent to the dielectric layer. The second portion contacts with an opposite side of the dielectric layer from the first semiconductor layer. The second electrode contacts with an opposite side of the second layer from the emitting layer.
1. A semiconductor light emitting device comprising:
a body;
a first semiconductor layer of a first conductivity type, the first semiconductor layer being apart from the body in a first direction, the first semiconductor layer including a first part region, a second part region, and a third part region, the third part region being arranged with the first part region in a second direction crossing the first direction, the second part region being disposed between the first part region and the third part region;
a second semiconductor layer of a second conductivity type, the second semiconductor layer being provided between the body and the third part region;
a light emitting layer provided between the third part region and the second semiconductor layer;
a dielectric layer having a refractive index lower than a refractive index of the first semiconductor layer, the dielectric layer including a first dielectric portion being provided between the body and the second part region;
a second electrode between the second semiconductor layer and a part of the body, the second electrode being electrically connected with the body;
a first electrode including a first portion and a second portion, the first portion being provided between the first part region and the body, the first portion being in contact with the first part region, the second portion being provided between the first dielectric portion and the body.
2. The device according to claim 1 , wherein
the first portion has a first length in a third direction crossing the first direction and being perpendicular to the second direction,
the first portion having a second length in the second direction,
the first portion extends in the third direction, and
the first length is longer than the second length.
3. The device according to claim 2 , wherein
the second electrode has a contact portion in contact with the second semiconductor layer,
the contact portion has a third length in the second direction, and
the second length is shorter than the third length.
4. The device according to claim 1 , wherein
the second electrode has a contact portion in contact with the second semiconductor layer, and
an area of the contact portion is larger than an area of the first electrode.
5. The device according to claim 1 , further comprising
a pad,
the first electrode including an extension portion not overlapping the first semiconductor layer in the first direction, and
at least a part of the pad being arranged with the first semiconductor layer in a direction perpendicular to the first direction, the pad being in contact with the extension portion.
6. The device according to claim 5 , wherein
the first portion has a first length in a third direction crossing the first direction and being perpendicular to the second direction,
the first portion having a second length in the second direction,
the first portion extends from the pad side in the third direction, and
a length in the second direction of the pad is longer than a length in the second direction of the first electrode.
7. The device according to claim 1 , wherein the dielectric layer further includes a second dielectric portion,
a part of the second dielectric portion is provided between the body and the first portion,
another part of the second dielectric portion being provided between the body and the second portion.
8. The device according to claim 1 , wherein the first electrode includes
a first conductive layer including the first portion; and
a second conductive layer including the second portion,
the first conductive layer is provided between the second conductive layer and the first semiconductor layer, and
the second conductive layer contains a material different from a material included in the first conductive layer.
9. The device according to claim 8 , wherein at least a part of a peripheral portion of the first conductive layer is provided between the dielectric layer and the first semiconductor layer.
10. The device according to claim 1 , wherein the first electrode includes
a first conductive layer including the first portion and the second portion; and
a second conductive layer,
the first conductive layer is provided between the second conductive layer and the first semiconductor layer, and
the second conductive layer contains a material different from a material included in the first conductive layer.
11. The device according to claim 1 , wherein
the second electrode includes
a contact portion in contact with the second semiconductor layer, and
a metal portion,
the contact portion is provided between the metal portion and the second semiconductor layer,
the metal portion is in contact with the body, and
the metal portion overlaps the first electrode in the first direction.
12. The device according to claim 1 , wherein
the first semiconductor layer has a first surface and a second surface on an opposite side to the first surface,
the first electrode is in contact with the second surface,
the first semiconductor layer has concavities-convexities provided at the first surface, the concavities-convexities are provided with a pitch not less than a peak wavelength of emitted light emitted from the light emitting layer.
13. The device according to claim 1 , wherein
the first conductivity type is an n type, and
the second conductivity type is a p type.
14. The device according to claim 1 , wherein a material of at least a portion of the second electrode contains Ag, the portion of the second electrode is in contact with the second semiconductor layer.
15. The device according to claim 1 , wherein a material of at least a portion of the first electrode contains at least one of a metal, an alloy, and ITO,
the metal includes one selected from a group consisting of Ti, Au, Al, and Ag,
the alloy includes one selected from a group consisting of Ti, Au, Al, and Ag, and
the portion of the first electrode is in contact with the second surface.
16. The device according to claim 1 , wherein the dielectric layer contains at least one of SiO 2 , SiN, and SiON.
17. The device according to claim 1 , wherein
the first semiconductor layer includes a first GaN, and
the second semiconductor layer includes a second GaN.
18. The device according to claim 1 , wherein a distance between the first electrode and the second semiconductor layer is longer than the thickness of the dielectric layer.