Optoelectronic Device with Modulation Doping

• US 20150060908A1
• Filed: 09/03/2014
• Published: 03/05/2015
• Est. Priority Date: 09/03/2013
• Status: Active Grant

• Current Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Sensor Electronic Technology Incorporated (Seoul Semiconductor Co., Ltd.)
• Inventors: Jain, Rakesh, Shatalov, Maxim S., Yang, Jinwei, Dobrinsky, Alexander, Shur, Michael, Gaska, Remigijus
• Granted Patent: US 9,653,631 B2
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 31/035272 characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

An improved heterostructure for an optoelectronic device is provided. The heterostructure includes an active region, an electron blocking layer, and a p-type contact layer. The p-type contact layer and electron blocking layer can be doped with a p-type dopant. The dopant concentration for the electron blocking layer can be at most ten percent the dopant concentration of the p-type contact layer. A method of designing such a heterostructure is also described.

Claims

1. A heterostructure comprising:

an active region;

a p-type contact layer having a p-type contact layer dopant concentration; and

an electron blocking layer located between the active region and the p-type contact layer, wherein a p-type dopant concentration in the electron blocking layer is at most ten percent of the p-type contact layer dopant concentration.

2. The heterostructure of claim 1, further comprising a p-type interlayer located between the electron blocking layer and the p-type contact layer, wherein a dopant concentration in the p-type interlayer increases from a dopant concentration comparable to the p-type dopant concentration in the electron blocking layer to a dopant concentration comparable to the p-type contact layer dopant concentration in a direction from the electron blocking layer to the p-type contact layer.

3. The heterostructure of claim 2, wherein the p-type interlayer further includes a varying semiconductor alloy composition that changes from a semiconductor alloy composition comparable to a semiconductor alloy composition of the electron blocking layer to a semiconductor alloy composition comparable to a semiconductor alloy composition of the p-type contact layer in a direction from the electron blocking layer to the p-type contact layer.

4. The heterostructure of claim 3, wherein the semiconductor alloy compositions are group III nitride materials.

5. The heterostructure of claim 4, wherein the electron blocking layer includes a region having an aluminum molar fraction at least three percent higher than a highest aluminum molar fraction in the active region.

6. The heterostructure of claim 2, wherein the p-type interlayer includes a plurality of sublayers, each sublayer having a semiconductor alloy composition that differs from a semiconductor alloy composition of an immediately adjacent sublayer by at least 0.5%.

7. The heterostructure of claim 1, wherein the electron blocking layer includes a plurality of sublayers, each sublayer having a semiconductor alloy composition that differs from a semiconductor alloy composition of an immediately adjacent sublayer by at least 0.5%.

8. The heterostructure of claim 7, wherein the sublayers have an increasing band gap towards a central portion of the electron blocking layer.

9. The heterostructure of claim 7, wherein the sublayers form a superlattice including a first group of a plurality of high aluminum content sublayers alternating with a second group of a plurality of low aluminum content sublayers.

10. The heterostructure of claim 9, wherein a thickness of at least one of the first group or the second group of sublayers increase towards a central portion of the electron blocking layer.

11. An optoelectronic device comprising:

an n-type contact layer having an n-type doping;

a p-type contact layer having a p-type contact layer dopant concentration;

an active region located between the n-type contact layer and the p-type contact layer; and

an electron blocking layer located between the active region and the p-type contact layer, wherein a p-type dopant concentration in the electron blocking layer is at most ten percent of the p-type contact layer dopant concentration.

12. The device of claim 11, further comprising a p-type interlayer located between the electron blocking layer and the p-type contact layer, wherein a dopant concentration in the p-type interlayer increases from a dopant concentration comparable to the p-type dopant concentration in the electron blocking layer to a dopant concentration comparable to the p-type contact layer dopant concentration in a direction from the electron blocking layer to the p-type contact layer.

13. The device of claim 12, wherein the p-type interlayer further includes a varying semiconductor alloy composition that changes from a semiconductor alloy composition comparable to a semiconductor alloy composition of the electron blocking layer to a semiconductor alloy composition comparable to a semiconductor alloy composition of the p-type contact layer in a direction from the electron blocking layer to the p-type contact layer.

14. The device of claim 12, wherein the p-type interlayer includes a plurality of sublayers, each sublayer having a semiconductor alloy composition that differs from a semiconductor alloy composition of an immediately adjacent sublayer by at least 0.5%.

15. The device of claim 11, wherein the electron blocking layer includes a plurality of sublayers, each sublayer having a semiconductor alloy composition that differs from a semiconductor alloy composition of an immediately adjacent sublayer by at least 0.5%.

16. A method of fabricating a device, the method comprising:

creating a device design for the device using a computer system, wherein the device design includes a heterostructure comprising;

an active region;

a p-type contact layer having a target p-type contact layer dopant concentration; and

an electron blocking layer located between the active region and the p-type contact layer, wherein a target p-type dopant concentration for the electron blocking layer is at most ten percent of the target p-type contact layer dopant concentration; and

providing the device design for use in fabricating the device according to the device design.

17. The method of claim 16, wherein the creating uses a device design for a model device having a target reliability, wherein the model device has a similar heterostructure with different size dimensions.

18. The method of claim 17, wherein the creating includes determining a target dopant concentration for a target layer in the heterostructure by scaling a dopant concentration of a corresponding model layer of the model device using the planar areas for the target layer and the model layer and the thicknesses of the target layer and the model layer.

19. The method of claim 16, wherein the heterostructure further includes a p-type interlayer located between the electron blocking layer and the p-type contact layer, wherein a dopant concentration in the p-type interlayer increases from a dopant concentration comparable to the p-type dopant concentration in the electron blocking layer to a dopant concentration comparable to the p-type contact layer dopant concentration in a direction from the electron blocking layer to the p-type contact layer.

20. The method of claim 19, wherein at least one of:

the p-type contact layer, the electron blocking layer, or the p-type interlayer includes a plurality of sublayers, each sublayer having a semiconductor alloy composition that differs from a semiconductor alloy composition of an immediately adjacent sublayer by at least 0.5%.