MICRO LED DISPLAY PANEL
A micro LED display panel includes a micro LED array area including a plurality of micro LED structures. Each of the micro LED structures includes: a first type epitaxial layer; a light emitting layer formed on the first type epitaxial layer; and a second type epitaxial layer formed on the light emitting layer. The second type epitaxial layer includes: a micro lens structure and a bottom structure, the micro lens structure and the bottom structure being an integrative structure.
1 . A micro LED display panel, comprising a micro LED array area including a plurality of micro LED structures, wherein each of the micro LED structures comprises:
a first type epitaxial layer;
a light emitting layer formed on the first type epitaxial layer; and
a second type epitaxial layer formed on the light emitting layer, wherein the second type epitaxial layer comprises:
a micro lens structure and a bottom structure, the micro lens structure and the bottom structure being an integrated structure.
2 . The micro LED display panel according to claim 1 , wherein a mesa structure comprises the first type epitaxial layer, the light emitting layer, and the bottom structure of the second type epitaxial layer; and the micro LED structure further comprising a dielectric layer formed between adjacent mesa structures of adjacent micro LED structures.
3 . The micro LED display panel according to claim 2 , wherein a sidewall of the mesa structure is inclined.
4 . The micro LED display panel according to claim 2 , wherein the micro LED structure further comprises: a passivation layer formed on a sidewall surface of the mesa structure.
5 . The micro LED display panel according to claim 4 , wherein the passivation layer is further formed on a top surface of the dielectric layer.
6 . The micro LED display panel according to claim 4 , further comprising:
one or more IO (input/output) vias formed outside the micro LED array area and through the dielectric layer and the passivation layer;
one or more top connection pads corresponding to the one or more IO vias, wherein one top connection pad is formed on a top of one IO via;
an integrated circuit (IC) backplane provided at a bottom of the dielectric layer; and
one or more bottom pads provided on the IC backplane corresponding to plurality of micro LED structures, wherein a bottom of one IO via is bonded with one bottom pad.
7 . The micro LED display panel according to claim 4 , wherein the micro LED structure further comprises a reflective layer formed on a sidewall surface of a portion of the passivation layer.
8 . The micro LED display panel according to claim 7 , wherein the reflective layer is further formed on a bottom of the mesa structure.
9 . The micro LED display panel according to claim 8 , wherein a bottom contact is further formed on the bottom of the mesa structure and on an inner surface of the reflective layer.
10 . The micro LED display panel according to claim 7 , wherein a material of the reflective layer is selected from one or more of Al, Ag, Ti, Pt, Au, Ni, Cr, or Sn.
11 . The micro LED display panel according to claim 4 , wherein a material of the passivation layer is selected from one or more of SiO 2 , Si 3 N 4 , or Al 2 O 3 .
12 . The micro LED display panel according to claim 2 , further comprising an integrated circuit (IC) backplane formed at a bottom of the dielectric layer.
13 . The micro LED display panel according to claim 12 , wherein the micro LED structure further comprises: a bottom contact formed at a bottom of the first type epitaxial layer and bonded with a bottom pad of the IC backplane.
14 . The micro LED display panel according to claim 1 , wherein the micro LED structure further comprises a top transparent conductive layer formed on a surface of the micro lens structure.
15 . The micro LED display panel according to claim 14 , wherein a material of the top transparent conductive layer is selected from one of ITO (Indium Tin Oxide), Al doped ZnO, or Ga doped ZnO.
16 . The micro LED display panel according to claim 14 , wherein the top transparent conductive layer continuously covers a whole surface of the second type epitaxial layer.
17 . The micro LED display panel according to claim 16 , further comprising a top contact formed on the top transparent conductive layer between adjacent micro lens structures
18 . The micro LED display panel according to claim 14 , wherein a thickness of the top transparent conductive layer is in a range of 5 nm to 500 nm.
19 . The micro LED display panel according to claim 14 , further comprising an electrode pad formed on an edge of the micro LED array area and connected with the top transparent conductive layer.
20 . The micro LED display panel according to claim 19 , wherein an end of the top transparent conductive layer is formed on part of a top of the electrode pad and on a sidewall of the electrode pad.
21 . The micro LED display panel according to claim 19 , wherein a sidewall of the top transparent conductive layer is connected with a sidewall of the electrode pad.
22 . The micro LED display panel according to claim 21 , wherein a top of the electrode pad is higher than a top of an end of the top transparent conductive layer.
23 . The micro LED display panel according to claim 14 , further comprising:
an integrated circuit (IC) backplane provided at a bottom of the micro LED array area; and
a signal source electrically connected with the IC backplane and the top transparent conductive layer.
24 . The micro LED display panel according to claim 1 , wherein a material of the first type epitaxial layer is selected from one or more of GaN, AlGaN, GaP, AlGaInP, or AlInP; a material of the second type epitaxial layer is selected from one or more of AlInP, AlGaInP, GaN, or AlGaN; and the light emitting layer is a quantum well layer.
25 . The micro LED display panel according to claim 1 , wherein the micro lens structure and the bottom structure are made of a same material.
26 . The micro LED display panel according to claim 25 , wherein the micro lens structure is semi-spherical, conical, pyramidal, cylindrical, or circular truncated conical.
27 . The micro LED display panel according to claim 25 , wherein a height of the micro lens structure is in a range of 0.05 μm to 10 μm, and a diameter of a bottom cross section of the micro lens structure is in a range of 0.5 μm to 10 μm.
28 . The micro LED display panel according to claim 2 , wherein the second type epitaxial layer further comprises: an extrusion portion interconnected between adjacent micro LED structures.
29 . The micro LED display panel according to claim 28 , wherein the extrusion portion extends along a horizontal direction.
30 . The micro LED display panel according to claim 28 , wherein the micro LED structure further comprises: a passivation layer formed on a bottom surface of the extrusion portion and on a sidewall surface of the mesa structure.
31 . The micro LED display panel according to claim 30 , wherein the micro LED structure further comprises: a reflective layer formed on a sidewall surface of a portion of the passivation layer and on at least part under a bottom surface of the extrusion portion.
32 . The micro LED display panel according to claim 30 , wherein the micro LED structure further comprises: a top transparent conductive layer formed on a surface of the micro lens structure and on a top surface of the extrusion portion.