MICRO LED STRUCTURE AND MICRO LED PANEL
A micro LED structure and a full color micro LED panel provided by the disclosure comprises: at least three mesa structures. A first dielectric layer is formed between the first connecting layer and the second connecting layer, the third connecting layer is shared by the second mesa structure and the third mesa structure. The micro LED structure can improve the light emitting efficiency and reduce the cross talk between the adjacent micro LEDs.
1 . A micro LED structure, comprising:
an IC back plane;
a first mesa structure formed on the IC back plane, the first mesa structure comprising a first connecting layer;
a first dielectric layer formed on the first mesa structure;
a second mesa structure formed on the first dielectric layer, the second mesa structure comprising a second connecting layer and a third connecting layer; and
a third mesa structure formed on the third connecting layer, the third mesa structure comprising a fourth connecting layer;
wherein the second connecting layer and the fourth connecting layer are electrically connected with the IC back plane;
wherein the first connecting layer is electrically connected to the third connecting layer;
wherein the third connecting layer is electrically connected to a bottom surface of the third mesa structure; and
wherein each of the first, second, and third mesa structures comprises:
a first epitaxial layer having a first conductive type;
a quantum well layer on the first epitaxial layer; and
a second epitaxial layer on the quantum well layer, the second epitaxial layer having a second conductive type.
2 . The micro LED structure of claim 1 , wherein the first, second, and third mesa structures respectively form a first outline, a second outline, and a third outline in plan view, the third outline being disposed within the second outline, the second outline being disposed within the first outline.
3 . The micro LED structure of claim 2 , further comprising:
a first bonding layer formed under the first mesa structure, the first bonding layer bonding a bottom surface of the first mesa structure to the IC back plane;
a second bonding layer formed between the second connecting layer and the rest of the second mesa structure, the second bonding layer bonding a bottom surface of the rest of the second mesa structure to the second connecting layer; and
a third bonding layer formed between the third connecting layer and the rest of the third mesa structure, the third bonding layer bonding the bottom surface of the rest of the third mesa structure to the third connecting layer.
4 . The micro LED structure of claim 3 , wherein:
a sidewall of the first bonding layer is aligned with a sidewall of the first mesa structure;
a sidewall of the second bonding layer is aligned with a sidewall of the second mesa structure; and
a sidewall of the third bonding layer is aligned with a sidewall of the third mesa structure.
5 . The micro LED structure of claim 3 , wherein each of the first, second, and third bonding layers comprises:
a metal;
a composite metal; or
a transparent conductive material.
6 . The micro LED structure of claim 5 , wherein the transparent conductive material is silicon dioxide (SiO 2 ) or indium tin oxide (ITO).
7 . The micro LED structure of claim 3 , wherein the first dielectric layer comprises a first reflection layer.
8 . The micro LED structure of claim 7 , wherein the transparent conductive material is indium tin oxide (ITO).
9 . The micro LED structure of claim 7 , wherein a sidewall of the first reflection layer is aligned with a sidewall of the second mesa structure.
10 . The micro LED structure of claim 9 , wherein the first reflection layer comprises:
stacked transparent layers;
metal omnidirectional refection (ODR) layers;
stacked distributed Bragg reflection (DBR) layers; or
high-reflectivity metal.
11 . The micro LED structure of claim 9 , wherein the first reflection layer is electrically insulative.
12 . The micro LED structure of claim 7 , wherein the first reflection layer, the first connecting layer, and the second connecting layer are transparent.
13 . The micro LED structure of claim 7 , further comprising a second reflection layer formed between the third connecting layer and the third bonding layer.
14 . The micro LED structure of claim 13 , wherein a sidewall of the second reflection layer is aligned with a sidewall of the third mesa structure.
15 . The micro LED structure of claim 14 , wherein the second reflection layer comprises:
stacked transparent layers and metal omnidirectional refection (ODR) layers;
stacked distributed Bragg reflection (DBR) layers; or
a high-reflectivity metal.
16 . The micro LED structure of claim 13 , wherein the second reflection layer and the third connecting layer are transparent.
17 . The micro LED structure of claim 13 , wherein the second reflection layer is electrically insulative.
18 . The micro LED structure of claim 13 , further comprising a sidewall connecting structure on the third connecting layer, wherein the sidewall connecting structure is formed next to and configured to connect a sidewall of the second reflection layer and a sidewall of the third bonding layer.
19 . The micro LED structure of claim 1 , wherein each of the first, second, and third connecting layers comprises a transparent conductive material.
20 . The micro LED structure of claim 1 , further comprising a first through via formed next to one or more of the first, second, and third mesa structures, the first through via being electrically connected to the first connecting layer and the third connecting layer.
21 . The micro LED structure of claim 20 , further comprising a second through via and a third through via formed next to one or more of the first, second, and third mesa structures, wherein the second through via connects the second connecting layer to the IC back plane and the third through via connects the fourth connecting layer to the IC back plane.
22 . The micro LED structure of claim 1 , wherein:
the first conductive type is a P type semiconductor, and
the second conductive type is an N type semiconductor.
23 . The micro LED structure of claim 1 , wherein:
the first conductive type is an N type semiconductor, and
the second conductive type is a P type semiconductor.
24 . A full color micro LED panel, comprising a micro LED array, the micro LED array comprises a plurality of micro LED structures, wherein each of the plurality of micro LED structures comprises:
an IC back plane;
a first mesa structure formed on the IC back plane, the first mesa structure comprising a first connecting layer;
a first dielectric layer formed on the first mesa structure;
a second mesa structure formed on the first dielectric layer, the second mesa structure comprising a second connecting layer and a third connecting layer; and
a third mesa structure formed on the third connecting layer, the third mesa structure comprising a fourth connecting layer;
wherein the second connecting layer and the fourth connecting layer are electrically connected with the IC back plane;
wherein the first connecting layer is electrically connected to the third connecting layer;
wherein the third connecting layer is electrically connected to a bottom surface of the third mesa structure; and
wherein each of the first, second, and third mesa structures comprises:
a first epitaxial layer having a first conductive type;
a quantum well layer on the first epitaxial layer; and
a second epitaxial layer on the quantum well layer, the second epitaxial layer having a second conductive type.