MICRO LED, MICRO LED DISPLAY PANEL, AND EPITAXIAL STRUCTURE

1 . A micro LED comprising:

a bonding layer;

an N type semiconductor layer formed on the bonding layer;

a light emitting layer formed on the N type semiconductor layer;

a P type semiconductor layer formed on the light emitting layer; and

a top conductive layer formed on the P type semiconductor layer.

2 . The micro LED according to claim 1 , wherein the light emitting layer comprises at least one quantum well layer.

3 . The micro LED according to claim 2 , wherein a thickness of the quantum well layer is from 20 nm to 40 nm.

4 . The micro LED according to claim 2 , wherein the quantum well layer is GaInP/(Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.3 to 0.5.

5 . The micro LED according to claim 4 , wherein x is 1 to 2 times y.

6 . The micro LED according to claim 1 , wherein the N type semiconductor layer comprises a doped N type contact layer, an N type cladding layer, and an N type spacer layer from bottom to top.

7 . The micro LED according to claim 6 , wherein a doping concentration of the doped N type contact layer is from 2e 18 cm −3 to 1e 19 cm −3 .

8 . The micro LED according to claim 6 , wherein the N type cladding layer is Al x In 1-x P, wherein a range of x is from 0.1 to 0.5.

9 . The micro LED according to claim 6 , wherein the N type spacer layer is (Al x Ga 1-x )yIn 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.1 to 0.5.

10 . The micro LED according to claim 9 , wherein x is 1 to 2 times y.

11 . The micro LED according to claim 1 , wherein the P type semiconductor layer further comprises a P type spacer layer, a P type cladding layer, a first doped P type transition layer, a second doped P type transition layer, and a doped P type contact layer from bottom to top.

12 . The micro LED according to claim 11 , wherein, the P type spacer layer is (Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.3 to 0.5.

13 . The micro LED according to claim 12 , wherein x is 1 to 2 times y.

14 . The micro LED according to claim 11 , wherein the P type cladding layer is Al x In 1-x P, wherein x is from 0.3 to 0.5.

15 . The micro LED according to claim 11 , wherein the first doped P type transition layer is (Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.1 to 0.3, and a range of y is from 0.3 to 0.5.

16 . The micro LED according to claim 15 , wherein y is 1 to 5 times x.

17 . The micro LED according to claim 11 , wherein the second doped P type transition layer is Al x Ga 1-x As, wherein a range of x is from 0.5 to 0.9.

18 . The micro LED according to claim 11 , wherein the doped P type contact layer is GaAs.

19 . The micro LED according to claim 11 , wherein a doping concentration of the second doped P type transition layer is greater than a doping concentration of the first doped P type transition layer.

20 . The micro LED according to claim 19 , wherein a doping concentration of the doped P type contact layer is 1 to 10 times a doping concentration of the second doped P type transition layer.

21 . The micro LED according to claim 11 , wherein a doping concentration of the doped P type contact layer is greater than a doping concentration of the second doped P type transition layer.

22 . The micro LED according to claim 21 , wherein the doping concentration of the second doped P type transition layer is 2 to 4 times a doping concentration of the first doped P type transition layer.

23 . The micro LED according to claim 1 , wherein a thickness of the N type semiconductor layer is from 300 nm to 500 nm; and a thickness of the P type semiconductor layer is from 400 nm to 600 nm.

24 . The micro LED according to claim 23 , wherein a thickness from a top of the top conductive layer to a bottom of the N type semiconductor layer is not more than 2000 nm.

25 . The micro LED according to claim 1 , wherein a sidewall of the P type semiconductor layer, the light emitting layer, and the N type semiconductor layer is inclined.

26 . The micro LED according to claim 25 , wherein an inclined angle of the sidewall is from 55 degrees to 65 degrees.

27 . The micro LED according to claim 25 , wherein an inclined angle of the sidewall is greater than 85 degrees.

28 . The micro LED according to claim 25 , wherein a top surface area of the P type semiconductor layer is smaller than a top surface area of the N type semiconductor layer.

29 . The micro LED according to claim 1 , wherein a sidewall of the micro LED is vertical.

30 . The micro LED according to claim 1 , wherein the bonding layer further comprises a first metal bonding layer, a transparent bonding layer, and a second metal bonding layer from bottom to top.

31 . The micro LED according to claim 30 , wherein the transparent bonding layer comprises a plurality of sputter transparent bonding layers and a plurality of porous transparent bonding layers, the plurality of sputter transparent bonding layers and the plurality of porous transparent bonding layers being alternated layered.

32 . The micro LED according to claim 30 , the bonding layer further comprising:

a dielectric distributed Bragg reflection (DBR) layer between the transparent bonding layer and the first metal bonding layer; and

a side conductive structure provided on a side of the DBR layer for connecting the transparent bonding layer with the first metal bonding layer.

33 . A micro LED display panel comprises:

an integrated circuit (IC) backplane comprising a bottom pad array, the bottom pad array comprising a plurality of conductive bottom pads; and

a micro LED array formed on the IC backplane, the micro LED array comprising a plurality of micro LEDs;

wherein one micro LED of the plurality of micro LEDs is electrically connected with one bottom pad of the plurality of conductive bottom pads; and the micro LED comprises:

a bonding layer;

an N type semiconductor layer formed on the bonding layer;

a light emitting layer formed on the N type semiconductor layer;

a P type semiconductor layer formed on the light emitting layer; and

a top conductive layer formed on the P type semiconductor layer.

34 . The micro LED display panel according to claim 33 , wherein respective top conductive layers of the plurality of micro LEDs are interconnected.

35 . The micro LED display panel according to claim 34 , wherein the IC backplane further comprises a top connected pad, and the respective top conductive layers are connected with the top connected pad of the IC backplane.

36 . An epitaxial structure for a micro LED comprising:

a substrate;

an etch stop layer formed on the substrate;

a P type epitaxial layer formed on the etch stop layer;

a light emitting layer formed on the P type epitaxial layer; and

an N type epitaxial layer formed on the light emitting layer.

37 . The epitaxial structure according to claim 36 , wherein the light emitting layer comprises at least one quantum well layer.

38 . The epitaxial structure according to claim 37 , wherein a thickness of the quantum well layer is from 20 nm to 40 nm.

39 . The epitaxial structure according to claim 37 , wherein the quantum well layer is GaInP/(Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.3 to 0.5.

40 . The epitaxial structure according to claim 39 , wherein x is 1 to 2 times y.

41 . The epitaxial structure according to claim 36 , wherein the N type epitaxial layer comprises:

an N type spacer layer formed on the light emitting layer;

an N type cladding layer formed on the N type spacer layer; and

a doped N type contact layer formed on the N type cladding layer.

42 . The epitaxial structure according to claim 41 , wherein a doping concentration of the doped N type contact layer is from 2e 18 cm −3 to 1e 19 cm −3 .

43 . The epitaxial structure according to claim 41 , wherein the N type cladding layer is Al x In 1-x P, wherein a range of x is from 0.1 to 0.5.

44 . The epitaxial structure according to claim 41 , wherein the N type spacer layer is (Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.1 to 0.5.

45 . The epitaxial structure according to claim 44 , wherein x is 1 to 2 times y.

46 . The epitaxial structure according to claim 36 , wherein the P type epitaxial layer comprises:

a doped P type contact layer formed on the etch stop layer;

a second doped P type transition layer formed on the doped P type contact layer;

a first doped P type transition layer formed on the second doped P type transition layer;

a P type cladding layer formed on the first doped P type transition layer; and

a P type spacer layer formed on the P type cladding layer.

47 . The epitaxial structure according to claim 46 , wherein the P type spacer layer is (Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.5 to 0.9, and a range of y is from 0.3 to 0.5.

48 . The epitaxial structure according to claim 47 , wherein x is 1 to 2 times y.

49 . The epitaxial structure according to claim 46 , wherein the P type cladding layer is Al x In 1-x P, wherein x is from 0.3 to 0.5.

50 . The epitaxial structure according to claim 46 , wherein the first doped P type transition layer is (Al x Ga 1-x ) y In 1-y P, wherein a range of x is from 0.1 to 0.3, and a range of y is from 0.3 to 0.5.

51 . The epitaxial structure according to claim 50 , wherein y is 1 to 5 times x.

52 . The epitaxial structure according to claim 46 , wherein the second doped P type transition layer is Al x Ga 1-x As, wherein a range of x is from 0.5 to 0.9.

53 . The epitaxial structure according to claim 46 , wherein the doped P type contact layer is GaAs.

54 . The epitaxial structure according to claim 46 , wherein a doping concentration of the second doped P type transition layer is greater than a doping concentration of the first doped P type transition layer.

55 . The epitaxial structure according to claim 54 , wherein a doping concentration of the doped P type contact layer is 1 to 10 times the doping concentration of the second doped P type transition layer.

56 . The epitaxial structure according to claim 46 , wherein a doping concentration of the doped P type contact layer is greater than a doping concentration of the second doped P type transition layer.

57 . The epitaxial structure according to claim 56 , wherein the doping concentration of the second doped P type transition layer is 2 to 4 times a doping concentration of the first doped P type transition layer.

58 . The epitaxial structure according to claim 36 , wherein a thickness of the N type epitaxial layer is from 300 nm to 500 nm, and a thickness of the P type epitaxial layer is from 400 nm to 600 nm.

59 . The epitaxial structure according to claim 58 , wherein a thickness from a top of the N type epitaxial layer to a bottom of the P type epitaxial layer is not greater than 1000 nm.