Group III-nitride light emitting device
View Patent ↗The present invention provides a group III-nitride light emitting device improved in operating voltage and electrostatic discharge characteristics. The group III-nitride light emitting device comprises a lower n-type clad layer, a current spreading layer, an upper n-type clad layer, an active layer and an p-type clad layer formed in their order on a substrate. The current spreading layer includes a SiC layer.
1. A group III-nitride light emitting device comprising:
a lower n-type clad layer, a current spreading layer and an upper n-type clad layer formed in their order on a substrate; and
an active layer and a p-type clad layer formed in their order on the upper n-type clad layer,
wherein the current spreading layer comprises a SiC layer.
2. The group III-nitride light emitting device according to claim 1 , wherein the SiC layer comprises an undoped SiC layer.
3. The group III-nitride light emitting device according to claim 1 , wherein the SiC layer comprises an n-doped SiC layer.
4. The group III-nitride light emitting device according to claim 3 , wherein a dopant added to the SiC layer comprises one selected from a group consisting of N, Ti, Cr and P.
5. The group III-nitride light emitting device according to claim 1 , wherein the current spreading layer further comprises high-concentration n-doped Al x Ga y In 1-x-y N layers having electron concentration higher than that of the lower n-type clad layer, where 0≦x≦1, 0≦y≦1, and 0≦x+y≦1, and formed on and underneath the SiC layer, respectively.
6. The group III-nitride light emitting device according to claim 5 , wherein the current spreading layer further comprises at least one SiC layer on the high-concentration n-doped Al x Ga y In 1-x-y N layer formed on the SiC layer.
7. The group III-nitride light emitting device according to claim 5 , wherein the current spreading layer comprises a multilayer structure including the high-concentration n-doped Al x Ga y In 1-x-y N layer and the SiC layer stacked repeatedly.
8. The group III-nitride light emitting device according to claim 5 , wherein the high-concentration n-doped Al x Ga y In 1-x-y N layers have electron concentration of 1×10 21 cm −3 or less.
9. The group III-nitride light emitting device according to claim 1 , wherein the lower n-type clad layer has electron concentration of 1×10 18 to 5×10 18 cm −3 .
10. The group III-nitride light emitting device according to claim 5 , wherein the high-concentration n-doped Al x Ga y In 1-x-y N layer formed on the SiC layer has a composition identical to the high-concentration n-doped Al x Ga y In 1-x-y N layer formed underneath the SiC layer.
11. The group III-nitride light emitting device according to claim 5 , wherein the high-concentration n-doped Al x Ga y In 1-x-y N layer formed on the SiC layer has a composition different from the high-concentration n-doped Al x Ga y In 1-x-y N layer formed underneath the SiC layer.
12. The group III-nitride light emitting device according to claim 1 , wherein the upper n-type clad layer comprises a low-concentration n-doped Al x Ga y In 1-x-y N layer having electron concentration lower than that of the lower n-type clad layer, and formed just underneath the active layer.
13. The group III-nitride light emitting device according to claim 12 , wherein the low-concentration n-doped Al x Ga y In 1-x-y N layer has electron concentration of at least 1×10 16 cm −3 .
14. The group III-nitride light emitting device according to claim 12 , wherein the low-concentration n-doped Al x Ga y In 1-x-y N layer has electron concentration of 1×10 16 cm −3 to 1×10 18 cm −3 .
15. The group III-nitride light emitting device according to claim 1 , wherein the group III-nitride light emitting device is a light emitting diode.
16. The group III-nitride light emitting device according to claim 1 , wherein the group III-nitride light emitting device is a laser diode.