Led with internally confined current injection area

Patent metadata

Field	Value
Publication number	US-2016336484-A1
Application number	US-201615223900-A
Country	US
Kind code	A1
Filing date	Jul 29, 2016
Priority date	Dec 27, 2013
Publication date	Nov 17, 2016
Grant date	—

Abstract

Methods and structures for forming arrays of LED devices are disclosed. The LED devices in accordance with embodiments of the invention may include an internally confined current injection area to reduce non-radiative recombination due to edge effects. Several manners for confining current may include etch removal of a current distribution layer, etch removal of a current distribution layer and active layer followed by mesa re-growth, isolation by ion implant or diffusion, quantum well intermixing, and oxide isolation.

First claim

What is claimed is:

1 . An LED device comprising:
an active layer between a first doped layer and a second doped layer, wherein the first doped layer is doped with a first dopant type and the second doped layer is doped with a second dopant type opposite the first dopant type; a current injection region located within the active layer; and a modified confinement barrier region within the active layer and laterally surrounding the current injection region to confine current that flows through the active layer to an interior portion of the LED device and away from sidewalls of the LED device.

2 . The LED device of claim 1 , wherein the active layer comprises a plurality of quantum well layers and a plurality of barrier layers, and the modified confinement barrier region comprises intermixed regions of the quantum well layers and the barrier layers.

3 . The LED device of claim 2 , wherein the modified confinement barrier region is characterized by a larger bandgap than the quantum well layers within the current injection region.

4 . The LED device of claim 3 wherein, the modified confinement barrier region contains a higher aluminum concentration than the quantum well layers within the current injection region.

5 . The LED device of claim 2 , wherein the LED device has a maximum lateral dimension of 50 μm or less.

6 . The LED device of claim 5 , further comprising a bottom conductive contact bonded to a bottom electrode of a subpixel within a display area of a display substrate.

7 . The LED device of claim 6 , wherein the bottom conductive contact is formed on the second doped layer.

8 . The LED device of claim 6 , wherein the bottom conductive contact is bonded to a bottom electrode of a subpixel within a display area of a display substrate.

9 . The LED device of claim 8 , wherein the bottom conductive contact comprises a metal stack.

10 . The LED device of claim 9 , wherein the metal stack comprises a gold layer diffused with a bonding layer on the bottom electrode.

11 . The LED device of claim 5 , wherein the current injection region has a maximum width of 10 μm or less.

12 . The LED device of claim 2 , wherein the modified confinement barrier region comprises an impurity concentration.

13 . The LED device of claim 12 , wherein a profile of the impurity concentration extends through the second doped layer and the active layer.

14 . The LED device of claim 12 , wherein the profile of the impurity concentration is concentrated about the active layer.

15 . The LED device of claim 13 , wherein the impurity concentration comprises Zn or Mg.

16 . The LED device of claim 13 , wherein the impurity concentration comprises Si.

17 . The LED device of claim 13 , further comprising:
a first cladding layer between the first doped layer and the active layer; and a second cladding layer between the second doped layer and the active layer; wherein the profile of the impurity concentration extends through the second doped layer, the second cladding layer, and the active layer.

18 . The LED device of claim 2 , wherein the LED device is designed for red color emission.

19 . The LED device of claim 18 , wherein the first doped layer is n-type, and the second doped layer is p-type.

20 . The LED device of claim 19 , wherein the active layer comprises a material selected from the group consisting of AlGaInP, AlInP, AlGaP, AlGaAs, and InGaP.

Assignees

• Apple Inc

Inventors

• Mcgroddy Kelly
• Hu Hsin-Hua
• Bibl Andreas
• Chan Clayton Ka Tsun
• Haeger Daniel Arthur

Classifications

• H10W72/07178

  Means for aligning · CPC title

• H10W72/07141

  Means for applying energy, e.g. ovens or lasers · CPC title

• H10W72/0711

  Apparatus therefor · CPC title

• H10W70/093

  Connecting or disconnecting other interconnections thereto or therefrom, e.g. connecting bond wires or bumps · CPC title

• H10W90/00

  Package configurations · CPC title