Fluidic assembly top-contact LED disk

• US 10,115,862 B2
• Filed: 04/07/2015
• Issued: 10/30/2018
• Est. Priority Date: 12/27/2011
• Status: Active Grant

• Current Assignee: Elux Inc.
• Original Assignee: Elux Inc.
• Inventors: Zhan, Changqing, Schuele, Paul John, Crowder, Mark Albert, Garner, Sean Mathew, Kiczenski, Timothy James
• Primary Examiner(s): Fan, Bo
• Application Number:
  US14/680,618
• Publication Number:
  US 20150214430A1
• Time in Patent Office: 1,302 Days
• Field of Search: 257 13, 438 28
• CPC Class Codes: H01L 2224/95101 in a liquid medium
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A method is provided for forming a direct emission display. The method provides a transparent substrate with an array of wells formed in its top surface. A fluid stream is supplied to the substrate top surface comprising a plurality of top-contact light emitting diode (LED) disks. The wells are filled with the LED disks. A first array of electrically conductive lines is formed over the substrate top surface to connect with a first contact of each LED disk, and a second array of electrically conductive lines is formed over the substrate top surface to connect with a second contact of each LED disk. An insulator over the disk exposes an upper disk (e.g., p-doped) contact region. A via is formed through the disk, exposing a center contact region of a lower (e.g., n-doped) disk contact region. Also provided are a top-contact LED disk and direct emission display.

Claims

1. A top-contact light emitting diode (LED) display, the display comprising:

a transparent substrate with a top surface comprising a number of wells;

a top-contact LED formed in each of the number of wells, each LED comprising;

a lower disk comprising a material with a first dopant selected from a group consisting of;

a p-dopant, and an n-dopant;

the lower disk having a bottom surface and a top surface;

a multiple quantum well (MQW) disk overlying the lower disk top surface;

an upper disk comprising a material with a second dopant, wherein the second dopant is opposite the first dopant;

the upper disk having a bottom surface overlying the MQW disk, a top surface and a first diameter;

an electrical insulator disk overlying the upper disk top surface, having a second diameter smaller than the first diameter such that at least a portion of a perimeter of the upper disk extending to an outer edge of the upper disk top surface remains uncovered by the electrical insulator disk; and

, a via formed through the electrical insulator disk upper disk, and MQW disk, exposing a center contact region of the lower disk top surface.

2. The display of claim 1 wherein the electrical insulator disk is transparent.

3. The display of claim 1 wherein the lower disk is a material selected from a group consisting of p-doped gallium nitride (p-GaN), p-doped aluminum gallium indium phosphide (p-AlGaInP), n-doped gallium nitride (n-GaN), and n-doped aluminum gallium indium phosphide (n-AlGaInP).

4. The display of claim 1 wherein the electrical insulator disk is centered over the upper disk top surface;

and, wherein the upper disk contact region is formed around a circumference of the upper disk top surface.

5. A direct emission display comprising:

a transparent substrate with a top surface comprising an array of wells;

a top-contact LED formed in each well, each LED comprising;

a lower disk comprising a material with a first dopant selected from a group consisting of;

a p-dopant, and an n-dopant;

wherein the lower disk has a bottom surface and a top surface;

a multiple quantum well (MQW) disk overlying the lower disk;

an upper disk comprising a material with a second dopant, wherein the second dopant is opposite the first dopant;

the upper disk having a bottom surface overlying the MQW disk, a top surface, and a first diameter;

an electrical insulator disk overlying the upper disk top surface, having a second diameter smaller than the first diameter such that at least a portion of a perimeter of the upper disk extending to an outer edge of the upper disk top surface remains uncovered by the electrical insulator disk, wherein a portion of the upper disk top surface that remains uncovered by the electrical insulator disk is an upper disk contact region;

a via formed through the electrical insulator disk, upper disk, and MQW disk, exposing a center contact region of the lower disk top surface;

a first array of electrically conductive lines connected to the center contact region of each of the LED lower disks;

a second array of electrically conductive lines connected to the LED upper disk contact regions; and

,

a dielectric material interposed between the first and second of electrically conductive lines.

6. The display of claim 5 wherein the electrical insulator disk and dielectric are transparent.

7. The display of claim 5 wherein the lower disk is a material selected from a group consisting of:

p-doped gallium nitride (p-GaN), p-doped aluminum gallium indium phosphide (p-AlGaInP), n-doped gallium nitride (n-GaN), and n-doped aluminum gallium indium phosphide (n-AlGaInP).

8. The display of claim 5 wherein the electrical insulator disk has a center overlying an upper disk center;

wherein the upper disk contact region is formed around a circumference of the upper disk top surface; and

,

the display further comprising;

a dielectric extension formed over a region of the upper disk contact region.

9. The display of claim 8 wherein each well has a third diameter;

and,

wherein the first array of electrically conductive lines form a pair of opposing top disk contact arms overlying each well each top disk contact arm having a length of x extending over the well, where x is greater than (the third diameter−

first diameter)/2.

10. The display of claim 9 wherein the lower disk contact region has a fourth diameter;

and,

wherein the second array of electrically conductive lines form a bottom disk contact arm overlying each well, each bottom disk contact arm having a length of y extending over the well and the dielectric extension, where y is greater than (the third diameter+the fourth diameter)/2.

11. The display of claim 10 wherein the bottom disk contact arm is orthogonal to both top disk contact arms in each well.

12. The display of claim 5 where the electrical insulator disk is transparent.

13. A top-contact light emitting diode (LED) display, the display comprising:

a transparent substrate with a top surface comprising a number of wells;

a top-contact LED formed in each of the number of wells, each LED comprising;

a lower disk having a first surface and a second surface, wherein the lower disk is formed of a first material selected from a group consisting of;

a p-doped material, and an n-doped material;

a multiple quantum well (MQW) having a third surface and a fourth surface, and wherein the fourth surface of the MQW is adjacent the first surface of the lower disk;

an upper disk having a fifth surface exhibiting a first width and a sixth surface, wherein the fifth surface is opposite the sixth surface, wherein the sixth surface of the upper disk is adjacent the third surface of the MQW, wherein the upper disk is formed of a second material selected from a group consisting of;

a p-doped material, and an n-doped material; and

wherein the second material is doped opposite the first material; and

an electrical insulator exhibiting a second width that is smaller than the first width, wherein the electrical insulator overlies a central region of the fifth surface of the upper disk such that at least a portion of an outer perimeter of the fifth surface of the upper disk extending to an edge of the fifth surface is not covered by the electrical insulator.

14. The display of claim 13, wherein the LED further comprises:

an opening extending through the upper disk and the MQW such that a portion of the first surface of the lower disk is exposed.

15. The display of claim 14, wherein an inner edge of the opening including an edge of the upper disk and an edge of the MQW is covered by the electrical insulator.

16. The display of claim 14, wherein the outer perimeter of the fifth surface of the upper disk that is not covered by the electrical insulator is an upper disk contact region, and wherein the exposed portion of the first surface of the lower disk is a lower disk contact region.

17. The display of claim 13, wherein the first width is a first diameter, and wherein the second width is a second diameter.

18. The display of claim 17, wherein the second diameter is centered within the first diameter.

19. The display of claim 13, wherein the electrical insulator is transparent.

20. The display of claim 13, wherein the first material is selected from a group consisting of:

p-doped gallium nitride (p-GaN), p-doped aluminum gallium indium phosphide (p-AlGaInP), n-doped gallium nitride (n-GaN), and n-doped aluminum gallium indium phosphide (n-AlGaInP).

21. The display of claim 13, wherein the second material is selected from a group consisting of:

p-doped gallium nitride (p-GaN), p-doped aluminum gallium indium phosphide (p-AlGaInP), n-doped gallium nitride (n- GaN), and n-doped aluminum gallium indium phosphide (n-AlGaInP).

22. The display of claim 13, wherein the first material is the same as the second material.

23. The display of claim 13, wherein the LED is incorporated into a direct emission display, and wherein the direct emission display comprises:

a substrate with a top surface comprising a plurality of wells, and wherein the LED is deposited into one of the wells.

a first electrically conductive line electrically connected to the lower disk;

a second electrically conductive line connected to the upper disk; and

,

a dielectric material interposed between the first electrically conductive line and the second electrically conductive line.

24. The display LED of claim 23, wherein the substrate is a transparent substrate.

25. The display of claim 23, wherein the electrical insulator has a center overlying an upper disk center, wherein a portion of the outer perimeter of the fifth surface of the upper disk that is not covered by the electrical insulator is an upper disk contact region formed around a circumference of the fifth surface of the upper disk;

and wherein the display further comprises;

a dielectric extension formed over a region of the upper disk contact region.

26. The display of claim 23, wherein the well into which the LED is deposited has a third width;

and wherein the first electrically conductive line forms a pair of opposing top disk contact arms overlying a top disk contact arm having a length of x extending over the well, where x is greater than (the third diameter-first diameter)/2.

27. The display of claim 24, wherein the lower disk contact region has a fourth diameter;

and wherein the second electrically conductive line forms a bottom disk contact arm overlying the well into which the LED is deposited, each bottom disk contact arm having a length of y extending over the well into which the LED is deposited and the dielectric extension, where y is greater than (the third diameter + the fourth diameter)/2.

28. The display of claim 25, wherein the bottom disk contact arm is orthogonal to both top disk contact arms in the well into which the LED is deposited.