Semiconductor light emitting device
A Si substrate 1 , a metal adhesion layer 2 , a reflective metal film 3 comprising a multilayer of metallic material having a light reflectivity, a SiO 2 film 4 , an ohmic contact portion 5 provided at a predetermined position of the SiO 2 film 4 , a GaP layer 6 including a Mg-doped GaP layer 6 A and a Zn-doped GaP layer 6 B, a p-type GaInP interposed layer 7 , a p-type AlGaInP cladding layer 8 , an undoped MQW active layer 9 , an n-type AlGaInP cladding layer 10 , an n-type AlGaInP window layer 11 , an n-type GaAs contact layer 12 , a first electrode 13 , and a second electrode 14 are formed. The ohmic contact portion 5 is distant from the light emitting part including the p-type AlGaInP cladding layer 8 , the undoped MQW active layer 9 and the n-type AlGaInP cladding layer 10 by not less than 300 nm.
1. A semiconductor light emitting device, comprising:
an epitaxial layer including a light emitting part;
an ohmic contact portion contacting with the epitaxial layer;
a reflective metal film for reflecting a light emitted from the light emitting part, and contacting with the ohmic contact portion, and being opaque with respect to the light emitted from the light emitting part;
a supporting substrate, one surface of the supporting substrate bonded to the reflective metal film via a metal adhesion layer;
a first electrode provided at one surface of the epitaxial layer; and
a second electrode at another surface of the supporting substrate;
wherein the ohmic contact portion comprises Be and is distant from the light emitting part by not less than 300 nm.
2. The semiconductor light emitting device according to claim 1 , wherein the epitaxial layer comprises a GaP layer as a second conductivity type semiconductor layer, and the GaP layer is contacting with the ohmic contact portion.
3. The semiconductor light emitting device according to claim 1 , wherein the light emitting part comprises an active layer, a first conductivity type semiconductor layer comprising a material selected from a group consisting of Se, Si and Te, and a second conductivity type semiconductor layer comprising a dopant selected from a group consisting of Mg and Zn.
4. The semiconductor light emitting device according to claim 2 , wherein the second conductivity type semiconductor layer comprises a first layer doped with Mg and a second layer doped with Zn sequentially deposited.
5. The semiconductor light emitting device according to claim 4 , further comprising:
a third layer provided between the first layer and the second layer,
wherein the third layer is not positively doped with dopant, and the second layer is contacting with the ohmic contact portion.
6. The semiconductor light emitting device according to claim 5 , wherein a thickness of the third layer is from 5 nm to 200 nm.
7. The semiconductor light emitting device according to claim 1 , further comprising:
a layer having a bandgap energy smaller than that of an active layer constituting the light emitting part between the first electrode and the epitaxial layer.
8. The semiconductor light emitting device according to claim 7 , wherein a thickness of the layer having the bandgap energy smaller than that of the active layer is from 5 to 200 nm.
9. The semiconductor light emitting device according to claim 3 , further comprising:
an interposed layer comprising Ga X In 1−X P (0.6≦X) between the ohmic contact portion and the second conductivity type semiconductor layer constituting the light emitting part.
10. The semiconductor light emitting device according to claim 3 , further comprising:
an undoped layer between the active layer and the first conductivity type semiconductor layer or the second conductivity type semiconductor layer, or between the active layer, the first conductivity type semiconductor layer and the second conductivity type semiconductor layer.
11. The semiconductor light emitting device according to claim 3 , wherein the active layer comprises a multiquantum well structure including 10 to 80 pairs of well layers.
12. The semiconductor light emitting device according to claim 1 , wherein the epitaxial layer comprises a plurality of layers provided above the light emitting part and being transparent with respect to the light emitted from the light emitting part.
13. The semiconductor light emitting device according to claim 2 , wherein the ohmic contact portion is buried in an oxide layer provided between the second conductivity type semiconductor layer and the reflective metal film, and a thickness of the oxide layer is within a range of ±30% of a thickness d determined based on a wavelength of the light emitted from the light emitting part and a refractive index of the oxide layer.
14. The semiconductor light emitting device according to claim 1 , wherein the supporting substrate comprises a material selected from a group consisting of Si, GaAs, and Ge.
15. The semiconductor light emitting device according to claim 1 , wherein the supporting substrate comprises a metal selected from a group consisting of Cu, Mo, W, and Ge, or an alloy of CuW.
16. The semiconductor light emitting device according to claim 1 , wherein the ohmic contact portion further comprises a transition metal.