Semiconductor light emitting device and method for manufacturing semiconductor light emitting device

1. A semiconductor light emitting device, comprising:

an n-type semiconductor layer including a nitride semiconductor;

a p-type semiconductor layer including a first p-side layer, a second p-side layer of Al x2 Ga 1-x2 N (0.05≦x2≦0.2), and a third p-side layer of Al x3 Ga 1-x3 N (0≦3≦x2), the first p-side layer including a nitride semiconductor including Mg, the second p-side layer being provided between the first p-side layer and the n-type semiconductor layer and including Mg, and the third p-side layer being provided between the first p-side layer and the second p-side layer and including Mg; and

a light emitting layer provided between the n-type semiconductor layer and the second p-side layer, the light emitting layer including a nitride semiconductor, a plurality of barrier layers, and a well layer provided between the plurality of barrier layers, the plurality of barrier layers including In y1 Ga 1-y1 N (0≦y1<1), the well layer including In y2 Ga 1-y2 N (0≦y2≦1 and y1<y2), and y1 is smaller than y2,

a concentration profile of Mg of a p-side region including the light emitting layer, the second p-side layer, and the third p-side layer including:

a first portion;

a second portion provided between the first portion and the first p-side layer;

a third portion provided between the first portion and the second portion, a Mg concentration of the third portion increasing at a first increase rate along a first direction from the n-type semiconductor layer toward the first p-side layer;

a fourth portion provided between the third portion and the second portion, a Mg concentration of the fourth portion increasing at a second increase rate along the first direction;

a fifth portion provided between the third portion and the fourth portion, a Mg concentration of the fifth portion increasing at a third increase rate along the first direction, the third increase rate being lower than the first increase rate and lower than the second increase rate;

a sixth portion provided between the fourth portion and the second portion, a Mg concentration of the sixth portion being not less than 1×10 20 cm −3 and not more than 3×10 20 cm −3 and being higher than the concentrations of Mg of the first portion, the second portion, the third portion, the fourth portion, and the fifth portion; and

a seventh portion provided between the sixth portion and the second portion, a Mg concentration of the seventh portion decreasing along the first direction,

an Al concentration in the p-side region having a maximum value at a first position,

the Al concentration being 1/100 of the maximum value at a second position arranged with the first position along the first direction in a region between the first position and a position corresponding to the first portion,

a Mg concentration at the second position being not less than 2×10 18 cm −3 ,

an In concentration in the p-side region has a maximum value at a third position,

the In concentration is 1/10 of the maximum value at a fourth position arranged with the third position along the first direction in a region between the third position and a position corresponding to the second portion, and

a Mg concentration at the fourth position is not less than 3×10 19 cm −3 .

2. The device according to claim 1 , wherein the Mg concentration at the fourth position is not more than 8×10 19 cm −3 .

3. The device according to claim 1 , wherein the second position is positioned inside the third portion.

4. The device according to claim 1 , wherein the second position is positioned inside the fifth portion.

5. The device according to claim 1 , wherein the second position is positioned inside the fourth portion.

6. The device according to claim 1 , wherein a peak wavelength of light emitted from the light emitting layer is not less than 400 nm and not more than 650 nm.

7. The device according to claim 1 , wherein a peak wavelength of light emitted from the light emitting layer is not less than 430 nm and not more than 460 nm.

8. The device according to claim 1 , wherein the Mg concentration at the second position is not more than 1.2×10 19 cm −3 .

9. The device according to claim 1 , wherein the Mg concentration of the fifth portion is not less than 1×10 19 cm −3 and not more than 3×10 19 cm −3 .

10. The device according to claim 1 , wherein a concentration of C (carbon) in the p-side region is not more than 5×10 18 cm −3 .

11. The device according to claim 1 , wherein a length of the fifth portion along the first direction is shorter than a length of the third portion along the first direction and shorter than a length of the fourth portion along the first direction.

12. The device according to claim 1 , wherein a length of the third portion along the first direction is not less than 5 nm and not more than 30 nm.

13. The device according to claim 1 , wherein a length of the fourth portion along the first direction is not less than 5 nm and not more than 30 nm.

14. The device according to claim 1 , wherein a length of the fifth portion along the first direction is not less than 3 nm and not more than 20 nm.

15. The device according to claim 1 , wherein a distance along the first direction between the first position and the second position is not less than 5 nm and not more than 30 nm.