MICRO LED ARRAY AND MICRO LED DISPLAY PANEL
A micro LED array includes a first type epitaxial layer formed including: an upper continuous layer; a bottom mesa array comprising a plurality of bottom mesas, wherein the bottom mesa array is formed at a bottom of the upper continuous layer and extends down from the upper continuous layer; and a trench formed between adjacent ones of the bottom mesas; a bottom dielectric layer formed at a bottom of the bottom mesa and filled in the trench, comprising a plurality of metal vias, wherein one of the plurality of metal vias corresponds to a bottom of one of the bottom mesas; a bottom via array comprising a plurality of bottom vias formed at bottoms of the bottom mesa array and in the bottom dielectric layer, one of the bottom vias corresponding to one of the bottom mesas; a bottom reflective layer formed under the bottom mesa, filled in the trench, and around the bottom via, wherein the bottom reflective layer is provided in the bottom dielectric layer; a light emitting layer formed on a top surface of the first type epitaxial layer; and a second type epitaxial layer formed on a top surface of the light emitting layer.
1 . A micro LED array, comprising:
a first type epitaxial layer formed including:
an upper continuous layer;
a bottom mesa array comprising a plurality of bottom mesas, wherein the bottom mesa array is formed at a bottom of the upper continuous layer and extends down from the upper continuous layer; and
a trench formed between adjacent ones of the bottom mesas;
a bottom dielectric layer formed at a bottom of the bottom mesa and filled in the trench, comprising a plurality of metal vias, wherein one of the plurality of metal vias corresponds to a bottom of one of the bottom mesas;
a bottom via array comprising a plurality of bottom vias formed at bottoms of the bottom mesa array and in the bottom dielectric layer, one of the bottom vias corresponding to one of the bottom mesas;
a bottom reflective layer formed under the bottom mesa, filled in the trench, and around the bottom via, wherein the bottom reflective layer is provided in the bottom dielectric layer;
a light emitting layer formed on a top surface of the first type epitaxial layer; and
a second type epitaxial layer formed on a top surface of the light emitting layer.
2 . The micro LED array according to claim 1 , wherein the bottom reflective layer comprises a reflective trench in the trench, and the bottom dielectric layer is filled in the reflective trench.
3 . The micro LED array according to claim 1 , further comprising a first bottom contact layer formed at a bottom surface of bottom mesa, the bottom dielectric layer formed at a bottom of the first bottom contact layer and filled in the trench.
4 . The micro LED array according to claim 3 , further comprising a second bottom contact layer formed at a bottom of the first bottom contact layer; wherein a material of second bottom contact layer is a reflective material.
5 . The micro LED array according to claim 4 , wherein an area of the second bottom contact layer corresponding to each bottom mesa is not less than an area of a top surface of each bottom via.
6 . The micro LED array according to claim 4 , wherein a material of the first bottom contact layer is a transparent conductive material, a material of the second bottom contact layer is metal, and a material of the bottom dielectric layer is SiO 2 or Si 3 N 4 .
7 . The micro LED array according to claim 3 , wherein a bottom of the bottom via extends down from a bottom of the first bottom contact layer.
8 . The micro LED array according to claim 1 , wherein an end of the bottom reflective layer is not connected to the bottom via.
9 . The micro LED array according to claim 3 , wherein a top of the bottom reflective layer under the bottom mesa is not lower than a bottom of the bottom via.
10 . The micro LED array according to claim 4 , wherein a top of the bottom reflective layer under the bottom mesa is not higher than a bottom of the second bottom contact layer.
11 . The micro LED array according to claim 10 , wherein an end of the bottom reflective layer near the bottom via is lower than the second bottom contact layer and lower than the other part of the bottom reflective layer.
12 . The micro LED array according to claim 10 , wherein a distance between a bottom of bottom mesa and a top of the bottom reflective layer under the bottom mesa is in a range of 5 nm to 1000 nm.
13 . The micro LED array according to claim 1 , wherein a thickness of the bottom reflective layer is in a range of 5 nm to 2000 nm, and a material of the bottom reflective layer is metal.
14 . The micro LED array according to claim 1 , wherein the light emitting layer is continuously formed on the first type epitaxial layer.
15 . The micro LED array according to claim 14 , wherein the upper continuous layer is a first upper continuous layer, the bottom mesa is a first bottom mesa, the bottom mesa array is a first bottom mesa array, and the trench is a first trench; wherein the second type epitaxial layer comprises:
a second bottom continuous layer;
a second upper mesa array comprising a plurality of second upper mesas, wherein the second upper mesa extends up from the second bottom continuous layer; and
a second trench formed between adjacent ones of the second upper mesas.
16 . The micro LED array according to claim 15 , wherein a sidewall of the first trench is vertical to the first upper continuous layer.
17 . The micro LED array according to claim 16 , wherein an error angle between the sidewall of the first trench and the first upper continuous layer is not more than ±5°.
18 . The micro LED array according to claim 16 , wherein a depth to width ratio of the first trench is not less than 5.
19 . The micro LED array according to claim 18 , wherein a width of the first trench is from 100 nm to 3 μm.
20 . The micro LED array according to claim 15 , wherein a thickness of the second bottom continuous layer is from 2 nm to 15 nm, and a thickness of the first upper continuous layer is from 2 nm to 15 nm.
21 . The micro LED array according to claim 15 , wherein a width of the second trench is greater than a width of the first trench.
22 . The micro LED array according to claim 15 , further comprising an isolation structure formed in the second trench.
23 . The micro LED array according to claim 22 , wherein the isolation structure is not transparent, and a material of the isolation structure is metal or isolation material.
24 . The micro LED array according to claim 22 , wherein the isolation structure comprises an isolation core and a reflective shell formed on the isolation core.
25 . The micro LED array according to claim 24 , wherein a material of the isolation core is not metal, and a material of the reflective shell is metal.
26 . The micro LED array according to claim 22 , further comprising a top dielectric layer formed on the second type epitaxial layer and the isolation structure, and at least part surface of each second upper mesa is exposed from the top dielectric layer.
27 . The micro LED array according to claim 26 , further comprising a top conductive layer formed on the top dielectric layer and on the exposed surface of the second upper mesa.
28 . The micro LED array according to claim 27 , further comprising a top contact formed between the exposed surface of the second upper mesa and the top conductive layer.
29 . The micro LED array according to claim 28 , wherein the top contact is not transparent, a material of the top contact is metal, and an area of the top contact is less than half of an area of the second upper mesa.
30 . The micro LED array according to claim 27 , wherein a top surface of the top conductive layer is not flat and conforms with a top surface of the top dielectric layer.
31 . The micro LED array according to claim 27 , further comprising a transparent micro lens array comprising a plurality of micro lenses formed on a top surface of the top conductive layer.
32 . The micro LED array according to claim 27 , wherein the top conductive layer and the top dielectric layer are transparent.
33 . The micro LED array according to claim 27 , wherein a material of the top dielectric layer is SiO 2 or Si 3 N 4 , and a material of the top conductive layer is transparent conductive material.
34 . The micro LED array according to claim 15 , wherein a material of the first type epitaxial layer is one of AlGaInP, InP, AlInP, GaAs, or GaP; a material of the second type epitaxial layer is one of AlGaInP, InP, AlInP, GaAs, or GaP; the light emitting layer is a quantum well layer; a diameter of the first bottom mesa is not greater than 50 μm; and a diameter of the second upper mesa is not greater than the diameter of the first bottom mesa.
35 . A micro LED array display panel, comprising:
an integrated circuit (IC) backplane comprising:
a first dielectric layer formed on the IC backplane; and
a top pad array comprising a plurality of top pads formed in the first dielectric layer; and
a micro LED array bonded with the IC backplane, wherein the micro LED array comprises:
a first type epitaxial layer formed including:
an upper continuous layer;
a bottom mesa array comprising a plurality of bottom mesas, wherein the bottom mesa array is formed at a bottom of the upper continuous layer and extends down from the upper continuous layer; and
a trench formed between adjacent ones of the bottom mesas;
a bottom dielectric layer formed at a bottom of the bottom mesa and filled in the trench, comprising a plurality of metal vias, wherein one of the plurality of metal vias corresponds to a bottom of one of the bottom mesas;
a bottom via array comprising a plurality of bottom vias formed at bottoms of the bottom mesa array and in the bottom dielectric layer, one of the bottom vias corresponding to one of the bottom mesas;
a bottom reflective layer formed under the bottom mesa, filled in the trench, and around the bottom via, wherein the bottom reflective layer is provided in the bottom dielectric layer;
a light emitting layer formed on a top surface of the first type epitaxial layer; and
a second type epitaxial layer formed on a top surface of the light emitting layer; and
wherein one bottom via corresponds to one first bottom mesa and is electrically bonded with one top pad, and the bottom dielectric layer is bonded with the first dielectric layer.