Nitride semiconductor device, method for manufacturing nitride semiconductor laminate, and method for manufacturing nitride semiconductor device

Abstract

According to the present invention, the luminous efficiency of a nitride semiconductor element is improved. This nitride semiconductor element comprises: a nitride semiconductor substrate that contains Al; and a semiconductor multilayer part that is disposed on the nitride semiconductor substrate. The semiconductor multilayer part comprises: a cladding layer having a first conductivity type, the cladding layer containing a nitride semiconductor having the first conductivity type; a light emitting layer which is disposed on the cladding layer having the first conductivity type, and which is formed of a nitride semiconductor comprising one or more quantum wells; and a cladding layer having a second conductivity type, the cladding layer being disposed on the light emitting layer, and being formed of a nitride semiconductor containing Al and having the second conductivity type. The deviation α from the uniformity of the alloy in the surface direction of a waveguide layer having the second conductivity type is 130 meV to 350 meV (inclusive).

Claims

1. A first conductivity type cladding layer containing a first conductivity type nitride semiconductor is formed on an Al-containing nitride semiconductor substrate. Under conditions where the wafer temperature is 850°C or higher and 970°C or lower, and the reactor pressure is 200 mbar or higher and 550 mbar or lower, a first conductivity type waveguide layer, an emissive layer containing a nitride semiconductor with one or more quantum wells, and a second conductivity type waveguide layer are formed on the first conductivity type cladding layer. A method for manufacturing a nitride semiconductor laminate, comprising forming a second conductivity type cladding layer containing a second conductivity type nitride semiconductor on the second conductivity type waveguide layer to form a semiconductor laminate on the nitride semiconductor substrate.

2. A method for manufacturing a nitride semiconductor laminate according to claim 1, wherein the wafer temperature Tw and the reactor pressure Vw when forming the light-emitting layer satisfy -2Tw + 2050 < Vw < -2Tw + 2350 (850°C ≤ Tw ≤ 970°C).

3. A portion of the second conductive cladding layer is formed under the conditions that the wafer temperature is 900°C or higher and 1000°C or lower, and the reactor pressure is 15 mbar or higher and 350 mbar or lower. A method for manufacturing a nitride semiconductor laminate according to claim 1, wherein the remaining portion of the second conductive cladding layer is formed under conditions where the wafer temperature is 1030°C or higher and 1100°C or lower, and the reactor pressure is 15 mbar or higher and 350 mbar or lower.

4. The method for manufacturing a nitride semiconductor laminate according to claim 3, wherein the reactor pressure when forming a part of the second conductive cladding layer is 15 mbar or more and 100 mbar or less.

5. During the formation of the first conductive cladding layer, the light-emitting layer, and the second conductive cladding layer, an organometallic gas is introduced. After forming the light-emitting layer, and before forming a portion of the second conductive cladding layer, the inflow of the organometallic gas is temporarily stopped. A method for manufacturing a nitride semiconductor laminate according to claim 1, wherein the inflow of the organometallic gas is temporarily stopped after forming a portion of the second conductive cladding layer and before forming the remaining portion of the second conductive cladding layer.

6. After forming the semiconductor laminated portion by the method for manufacturing a nitride semiconductor laminate according to any one of claims 1 to 5, Unnecessary portions of each layer of the semiconductor stack are removed by etching. A method for manufacturing a nitride semiconductor element, comprising forming electrodes on the semiconductor stacked portion and dividing the nitride semiconductor substrate on which each layer of the semiconductor stacked portion is formed into individual pieces by dicing.

7. Al-containing nitride semiconductor substrate, The semiconductor laminate is disposed on the nitride semiconductor substrate, The aforementioned semiconductor stacked portion is A first conductivity type cladding layer containing a first conductivity type nitride semiconductor, A first conductive waveguide layer disposed on the first conductive cladding layer, A light-emitting layer formed of a nitride semiconductor containing one or more quantum wells is disposed on the first conductive waveguide layer, A second conductive waveguide layer is disposed on the light-emitting layer, The second conductivity type waveguide layer is disposed on the second conductivity type waveguide layer and comprises a second conductivity type cladding layer made of a nitride semiconductor containing a second conductivity type Al, A nitride semiconductor element in which the deviation α from the uniformity of the alloy in the planar direction of the second conductive waveguide layer is 130 meV or more and 350 meV or less.

8. The nitride semiconductor element according to claim 7, wherein the thickness of the region at the interface between the quantum well layer and the barrier layer of the light-emitting layer in which the concentration profile of Al increases sharply is 0.3 nm or more and 0.6 nm or less.

9. The nitride semiconductor device according to claim 7 or 8, wherein the nitride semiconductor substrate is an AlN single crystal substrate.

10. The first conductive cladding layer is Al ａ Ga （１－ａ） A nitride semiconductor element according to claim 7 or 8, formed with N (0.65 < a ≤ 0.9).

11. The nitride semiconductor element according to claim 7 or 8, wherein the thickness of the first conductive cladding layer is 250 nm or more and 800 nm or less.

12. The second conductive contact layer is disposed on the second conductive cladding layer and is made of a nitride semiconductor containing GaN, The second conductive cladding layer is Al ｄ Ga （１－ｄ） A nitride semiconductor element according to claim 7 or 8, comprising N (0.1 ≤ d ≤ 1), having a compositional gradient in which the Al composition d decreases as it moves away from the nitride semiconductor substrate, and having a film thickness of 500 nm or less.

13. The nitride semiconductor element according to claim 12, wherein the second conductive cladding layer has a composition gradient in which the Al composition d decreases in the range of 1 to 0.7 as it moves away from the nitride semiconductor substrate.

14. The nitride semiconductor element according to claim 12, wherein the film thickness of the second conductive cladding layer is 250 nm or more and 500 nm or less.

15. The nitride semiconductor element according to claim 7 or 8, wherein the film thickness T0 of the first conductive cladding layer is 3300 × a - 2100 nm or more and 15700 × a - 10100 nm or less (where a is the ratio of Al atoms when the total number of group III atoms of the nitride semiconductor constituting the first conductive cladding layer is set to 1).

16. The resistivity of the first conductive cladding layer is 1 × 10⁻⁶ －３ Ω・cm or more 5×10 －３ The nitride semiconductor element according to claim 15, wherein the value is Ω·cm or less.

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