Granted Patent B2

US 7,804,869 · App. 11/419,592 · Granted Sep 28, 2010

Abstract

Claims (59)

1. A semiconductor device comprising:

an n-side waveguide layer;

an active layer in contact with the n-side waveguide layer;

a p-side waveguide layer in contact with the active layer;

an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising a first composition of two elements from group III of the periodic table and an element from group V of the periodic table; and

a cladding layer, the cladding layer including a first cladding sublayer in contact with the electron blocking layer and in contact with a second cladding sublayer, the first cladding sublayer being disposed between the second cladding sublayer and the electron blocking layer;

wherein the first cladding sublayer comprises a second composition of two elements from group III of the periodic table and an element from group V of the periodic table, the second composition being different from the first composition; and

wherein the first cladding sublayer has a higher conduction band level than the second cladding sublayer.

2. The semiconductor device of claim 1 , wherein the semiconductor device comprises a laser.

3. The semiconductor device of claim 1 , wherein the electron blocking layer has a higher conduction band level than the first cladding sublayer.

4. The semiconductor device of claim 1 , wherein the electron blocking layer is configured to form a potential barrier for the flow of electrons from the active layer and the p-side waveguide layer into the cladding layer.

5. The semiconductor device of claim 4 , wherein the potential barrier has a height of at least about 50 millielectron volts.

6. The semiconductor device of claim 1 , wherein the electron blocking layer is more than about ten nanometers thick.

7. The semiconductor device of claim 1 , wherein the electron blocking layer is doped with magnesium.

8. The semiconductor device of claim 1 , wherein the active layer comprises one or more quantum wells.

9. The semiconductor device of claim 1 , wherein the cladding layer is a stressed layer superlattice.

10. The semiconductor device of claim 9 , wherein the stressed layer superlatice comprises a plurality of sublayers comprising aluminum gallium nitride and a plurality of sublayers comprising gallium nitride.

11. The semiconductor device of claim 1 , further comprising two or more electrical contacts operative to allow the flowing of electrical current through at least a portion of the semiconductor device.

12. A semiconductor device comprising:

an n-side waveguide layer;

an active layer in contact with the n-side waveguide layer;

a p-side waveguide layer in contact with the active layer;

an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising aluminum gallium nitride of a first composition; and

a cladding layer, the cladding layer including a first cladding sublayer in contact with the electron blocking layer and in contact with a second cladding sublayer, the first cladding sublayer being disposed between the second cladding sublayer and the electron blocking layer;

wherein the first cladding sublayer comprises aluminum gallium nitride of a second composition different from the first composition; and

wherein the first cladding sublayer has a higher conduction band level than the second cladding sublayer.

13. The semiconductor device of claim 12 , wherein the aluminum gallium nitride of the second composition has a lower atomic percentage of aluminum than the aluminum gallium nitride of the first composition.

14. The semiconductor device of claim 12 , wherein the aluminum gallium nitride of the second composition has a lower concentration of aluminum than the aluminum gallium nitride of the first composition.

15. A method of forming a semiconductor device, the method comprising the steps of:

forming an n-side waveguide layer;

forming an active layer in contact with the n-side waveguide layer;

forming a p-side waveguide layer in contact with the active layer;

forming an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising a first composition of two elements from group III of the periodic table and an element from group V of the periodic table; and

forming a cladding layer, the cladding layer including a first cladding sublayer in contact with the electron blocking layer and in contact with a second cladding sublayer, the first cladding sublayer being disposed between the second cladding sublayer and the electron blocking layer;

wherein the first cladding sublayer comprises a second composition of two elements from group III of the periodic table and an element from group V of the periodic table, the second composition being different from the first composition; and

wherein the first cladding sublayer has a higher conduction band level than the second cladding sublayer.

16. The method of claim 15 , wherein the method comprises metal organic chemical vapor deposition.

17. The method of claim 15 , wherein the method comprises molecular beam epitaxy.

18. The method of claim 15 , wherein the method comprises epitaxial lateral overgrowth of gallium nitride on sapphire.

19. An apparatus including:

a semiconductor device comprising:

an n-side waveguide layer;

an active layer in contact with the n-side waveguide layer;

a p-side waveguide layer in contact with the active layer;

an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising a first composition of two elements from group III of the periodic table and an element from group V of the periodic table; and

a cladding layer, the cladding layer including a first cladding sublayer in contact with the electron blocking layer and in contact with a second cladding sublayer, the first cladding sublayer being disposed between the second cladding sublayer and the electron blocking layer;

wherein the first cladding sublayer comprises a second composition of two elements from group III of the periodic table and an element from group V of the periodic table, the second composition being different from the first composition; and

wherein the first cladding sublayer has a higher conduction band level than the second cladding sublayer; and

control circuitry, the control circuitry operative to control the semiconductor device.

20. The apparatus of claim 19 , wherein the apparatus is an optical disc drive capable of operating in accordance with at least one of the Blu-ray Disc format and the High Density Digital Versatile Disc format.

21. A semiconductor device comprising:

an n-side waveguide layer;

an active layer in contact with the n-side waveguide layer;

a p-side waveguide layer in contact with the active layer;

an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising a composition of three elements from group III of the periodic table and an element from group V of the periodic table; and

a cladding layer, the cladding layer including a first cladding sublayer in contact with the electron blocking layer and in contact with a second cladding sublayer, the first cladding sublayer being disposed between the second cladding sublayer and the electron blocking layer;

wherein the first cladding sublayer comprises a second composition of two elements from group III of the periodic table and an element from group V of the periodic table, the second composition being different from the first composition; and

wherein the first cladding sublayer has a higher conduction band level than the second cladding sublayer.

22. The semiconductor device of claim 21 , wherein the electron blocking layer comprises indium aluminum gallium nitride.

Assignments (10)