Light emitting diodes containing deactivated regions and methods of making the same

Patent metadata

Field	Value
Publication number	US-11264539-B2
Application number	US-201916684882-A
Country	US
Kind code	B2
Filing date	Nov 15, 2019
Priority date	Dec 3, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A light emitting device (LED) includes an n-doped semiconductor material layer, an active region including an optically active compound semiconductor layer stack configured to emit light located on the n-doped semiconductor material layer, a p-doped semiconductor material layer located on the active region, an anode contact contacting the p-doped semiconductor material layer, a reflector overlying and electrically connected to the anode contact, and a device-side bonding pad layer located on the reflector. The p-doped semiconductor material layer includes an electrically active region that is at least partially covered by the anode contact and an inactive region that an electrical conductivity less than 30% of the electrically active region.

First claim

The invention claimed is:

1. A light emitting diode (LED), comprising:
an n-doped semiconductor material layer;
an active region including an optically active compound semiconductor layer stack configured to emit light located on the n-doped semiconductor material layer;
a p-doped semiconductor material layer located on the active region;
an anode contact contacting the p-doped semiconductor material layer, wherein the p-doped semiconductor material layer includes an electrically active region that is at least partially covered by the anode contact and an inactive region that has an electrical conductivity less than 30% of the electrically active region;
a reflector overlying and electrically connected to the anode contact; and
a device-side bonding pad layer located on the reflector.

2. The LED of claim 1 , wherein the electrical conductivity of the inactive region is less than 10% of the electrical conductivity of the electrically active region.

3. The LED of claim 2 , wherein:
the electrically active region has electrical conductivity in a range from 1.0×10 5 S/m to 1.0×10 7 S/m; and
the inactive region has electrical conductivity in a range from 1.0×10 −4 S/m to 1.0×10 4 S/m.

4. The LED of claim 1 , wherein the inactive region has a lesser thickness than the electrically active region.

5. The LED of claim 1 , wherein the inactive region has a crystalline defect density that is at least ten times a crystalline defect density of the electrically active region.

6. The LED of claim 1 , wherein:
the p-doped semiconductor material layer comprises a magnesium doped gallium nitride layer; and
the inactive region and the electrically active region comprise portions of the magnesium doped gallium nitride layer that are doped with magnesium at the same atomic concentration.

7. The LED of claim 1 , wherein the entire electrically active region underlies the anode contact, a first portion of the inactive region underlies the anode contact, and a second portion of the inactive region does not underlie the anode contact.

8. The LED of claim 1 , wherein the entire electrically active region underlies the anode contact and the entire inactive region does not underlie the anode contact.

9. The LED of claim 1 , wherein an area of an interface between the electrically active region and the anode contact is equal to an area which during LED operation will produce a current density in a range from 0.90 times a peak external quantum efficiency of the LED and the peak external quantum efficiency of the LED.

10. The LED of claim 1 , wherein a ratio of the area of interface between the electrically active region and the anode contact to a total area of the LED is in a range from 0.0001 to 0.25.

11. A direct view display device comprising multiple instances of the LED of claim 1 arranged in an array configuration on a backplane, wherein each of the LEDs comprises a micro LED subpixel of the direct view display device.

Assignees

• Glo Ab
• Nanosys Inc

Inventors

• Batres Max
• Danesh Fariba
• Cich Michael J
• Chen Zhen

Classifications

• H10W90/00

  Package configurations · CPC title

• H10H20/018

  Bonding of wafers · CPC title

• H10H20/835 Primary

  Reflective materials · CPC title

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title

• H10H20/8162

  Current-blocking structures · CPC title