Micro-light-emitting diode device and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2016336486-A1
Application number	US-201615060885-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	May 13, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

A micro-light-emitting diode (micro-LED) device includes a first semiconductor layer, an active layer, and a second semiconductor layer. The first semiconductor layer includes a first bottom surface. The active layer is disposed on the first semiconductor layer. The second semiconductor layer disposed on the active layer includes a second bottom surface. A surface of the second semiconductor layer opposite to the active layer is a light-exiting surface of the micro-LED device. The second semiconductor layer has different thicknesses, in which a minimum thickness of the second semiconductor layer is located at an edge or at least one side of the second semiconductor layer. Vertical-projection zones of the first semiconductor layer, the active layer, and the second semiconductor layer on the first bottom surface are substantially the same.

First claim

What is claimed is:

1 . A micro-light-emitting diode device comprising:
a first semiconductor layer having a first bottom surface; an active layer disposed on the first semiconductor layer; and a second semiconductor layer having a second bottom surface, the second semiconductor layer being disposed on the active layer, a surface of the second semiconductor layer opposite to the active layer being a light-exiting surface of the micro-light-emitting diode device, the second semiconductor layer having multiple thicknesses, a minimum thickness of the second semiconductor layer being located at an edge or at least one side of the second semiconductor layer, vertical-projection zones of the first semiconductor layer, the active layer, and the second semiconductor layer on the first bottom surface being substantially the same.

2 . The micro-light-emitting diode device of claim 1 , wherein the light-exiting surface has a first apex and a first end point, a vertical distance between the first apex and the second bottom surface is a maximum among the thicknesses of the second semiconductor layer, and a vertical distance between the first end point and the second bottom surface is a minimum among the thicknesses of the second semiconductor layer.

3 . The micro-light-emitting diode device of claim 2 , wherein a vertical distance between the light-exiting surface and the second bottom surface gradually decreases from the first apex to the first end point.

4 . The micro-light-emitting diode device of claim 3 , wherein the light-exiting surface is in one of a spherical shape, an inverted-T shape, and a pointed shape.

5 . The micro-light-emitting diode device of claim 4 , wherein the light-exiting surface has at least one microstructure, the microstructure comprises a plurality of recessed portions or a plurality of raised portions.

6 . The micro-light-emitting diode device of claim 4 , wherein a shape of the first bottom surface of the first semiconductor layer is a circle or a polygon, and the shape and a size of the first bottom surface are substantially the same as a shape and a size of the second bottom surface.

7 . The micro-light-emitting diode device of claim 2 , wherein the vertical distance between the first apex and the second bottom surface is more than 0 micrometer and less than or equal to 20 micrometers.

8 . The micro-light-emitting diode device of claim 2 , wherein the vertical distance between the first end point and the second bottom surface is more than 0 micrometer and less than or equal to 10 micrometers.

9 . The micro-light-emitting diode device of claim 2 , wherein a difference between the vertical distance between the first apex and the second bottom surface and the vertical distance between the first end point and the second bottom surface is more than 0 micrometer and less than or equal to 10 micrometers.

10 . The micro-light-emitting diode device of claim 1 , wherein the second semiconductor layer has a first thickness corresponding to a first area, the second semiconductor layer has a second thickness corresponding to a second area, the first thickness is greater than the second thickness such that the second semiconductor layer has at least one step between the first area and the second area.

11 . The micro-light-emitting diode device of claim 10 , wherein an area corresponding to the first thickness of the second semiconductor layer occupies 65% to 85% of a total area of the light-exiting surface.

12 . The micro-light-emitting diode device of claim 10 , wherein the second area surrounds the first area.

13 . The micro-light-emitting diode device of claim 1 , further comprising an electrode layer disposed on the second semiconductor layer.

14 . A method for manufacturing a micro-light-emitting diode device comprising:
providing a first substrate; depositing a mask layer on the first substrate; patterning the mask layer to expose a portion of the first substrate; etching the exposed portion of the first substrate to form a recess, and a depth at a center of the recess being greater than a depth at an edge of the recess; removing the mask layer; forming a micro-light-emitting diode device comprising:
depositing a second semiconductor layer on the recess;
depositing an active layer on the second semiconductor layer; and
depositing a first semiconductor layer on the active layer;
transferring and reversing the first substrate and the micro-light-emitting diode device to a second substrate, the first semiconductor layer of the micro-light-emitting diode device being connected to the second substrate; etching the first semiconductor layer, the active layer and the second semiconductor layer in a same time to define a size of the micro-light-emitting diode device; and removing the first substrate.

15 . The method of claim 14 , wherein the second semiconductor layer is deposited in the recess and fills and levels up the recess.

16 . The method of claim 14 , wherein the portion of the first substrate is etched to form a first shape, and the second semiconductor layer is deposited on the recess to form a light-exiting surface, the light-exiting surface has a second shape, and the first shape and the second shape are the same.

17 . The method of claim 14 , further comprising:
providing a panel, and forming at least one thin film transistor on the panel; gripping the micro-light-emitting diode device to allow the micro-light-emitting diode device to be separated from the second substrate, and moving the micro-light-emitting diode device onto the thin film transistor; and forming an electrode layer on the second semiconductor layer of the micro-light-emitting diode device.

Assignees

• Au Optronics Corp

Inventors

• Lin Tsung-Yi
• Chang Cheng-Chieh

Classifications

• H01L33/24 Primary

  Electricity · mapped topic

• H01L2933/0016

  Electricity · mapped topic

• H01L33/58

  Electricity · mapped topic

• H01L33/36

  Electricity · mapped topic

• H01L2933/0058

  Electricity · mapped topic