Methods of transferring micro light emitting diode devices using electromagnetic apparatus and methods of fabrication
A magnetic apparatus includes a first structure including a first non-magnetic material, a second structure including a second non-magnetic material on a first portion of the first structure, a third structure including the second non-magnetic material on a second portion of the first structure. The magnetic apparatus further includes a first magnetic structure adjacent to a first sidewall of the second structure, a second magnetic structure adjacent to a first sidewall of the third structure, a third magnetic structure adjacent to a second sidewall of the second structure, adjacent to a second sidewall of the third structure and extends onto a third portion of the first structure. A magnet is coupled with the first, second and third magnetic structures.
1. A method for transferring micro-devices, the method comprising:
providing a plurality of device structures on a first layer over a first substrate;
placing a first pattern sensitive magnetic apparatus comprising a magnet in contact with the plurality of device structures;
removing the first layer between the plurality of device structures and the first substrate;
transferring the plurality of device structures onto a second layer of a second substrate;
positioning a second pattern sensitive magnetic apparatus directly over the plurality of device structures;
activating the magnet in the second pattern sensitive magnetic apparatus, wherein activating the magnet generates and confines a magnetic flux into a magnetic structure of the second pattern sensitive magnetic apparatus and magnetically couples individual ones of the plurality of device structures to a surface of the magnetic structure proximal to corresponding ones of the plurality of device structures;
lifting and removing the plurality of device structures from the second substrate;
placing the plurality of device structures on a third layer over a third substrate, wherein the third substrate is separate from the second substrate; and
releasing the plurality of device structures by decoupling from the second pattern sensitive magnetic apparatus.
2. The method of claim 1 , wherein removing the first layer comprises laser ablating the second layer to release the plurality of device structures.
3. The method of claim 1 , wherein transferring the plurality of device structures onto the second layer of the second substrate comprises positioning the plurality of device structures onto a tray comprising a plurality of trenches, wherein the individual ones of the plurality of device structures are placed into a corresponding individual ones of the plurality of trenches.
4. A method for transferring micro-devices, the method comprising:
providing a plurality of device structures on a first layer over a first substrate;
placing a first pattern sensitive magnetic apparatus comprising a magnet in contact with the plurality of device structures;
removing the first layer between the plurality of device structures and the first substrate;
transferring the plurality of device structures onto a tray having a second substrate comprising a plurality of trenches, wherein individual ones of the plurality of device structures are placed into a corresponding individual ones of the plurality of trenches;
positioning a second pattern sensitive magnetic apparatus directly over the plurality of device structures;
activating the magnet in the second pattern sensitive magnetic apparatus, wherein activating the magnet generates and confines a magnetic flux into a magnetic structure of the second pattern sensitive magnetic apparatus and magnetically couples the individual ones of the plurality of device structures to a surface of the magnetic structure proximal to corresponding ones of the plurality of device structures;
lifting and removing the plurality of device structures from the tray;
placing the plurality of device structures on a third layer over a third substrate, wherein the third substrate is separate from the second substrate; and
releasing the plurality of device structures by decoupling from the second pattern sensitive magnetic apparatus.
5. The method of claim 4 , wherein the individual ones of the plurality of trenches comprise a width that is between 15-20% greater than a lateral width of the individual ones of the plurality of device structures.
6. The method of claim 5 , wherein the individual ones of the plurality of device structures are laterally separated by a first spacing, wherein the individual ones of the plurality of trenches are laterally separated by a second spacing, wherein the second spacing is less than the first spacing, and wherein placing the individual ones of the plurality of device structures into a respective trench of the plurality of trenches further comprises placing the individual ones of the plurality of device structures away from sidewalls of the respective trench of the plurality of trenches.
7. The method of claim 6 , wherein placing the individual ones of the plurality of device structures in a respective individual ones of the plurality of trenches comprises filling a height of the respective individual ones of the plurality of trenches.
8. The method of claim 6 , wherein placing the individual ones of the plurality of device structures in a respective individual ones of the plurality of trenches causes the individual ones of the plurality of device structures to extend beyond an uppermost surface of the plurality of trenches.
9. The method of claim 4 , wherein the individual ones of the plurality of trenches comprise a plan view structure that is circular.
10. The method of claim 4 , wherein the individual ones of the plurality of trenches comprise a plan view structure that is rectangular.
11. The method of claim 4 , wherein the individual ones of the plurality of trenches comprise a plan view structure that is rectangular.
12. The method of claim 4 , wherein positioning the plurality of device structures comprises positioning the individual ones of the plurality of device structures into individual ones of the plurality of trenches that comprise a height that is sufficient to provide mechanical stability.
13. The method of claim 4 , wherein the tray comprises a dielectric material or a non-magnetic material.
14. A method of making a magnetic apparatus, the method comprising:
forming a first structure comprising a first non-magnetic material;
forming a second structure comprising a second non-magnetic material on a first portion of the first structure;
forming a third structure comprising the second non-magnetic material on a second portion of the first structure;
forming a first magnetic structure adjacent to a first sidewall of the second structure;
forming a second magnetic structure adjacent to a first sidewall of the third structure;
forming a third magnetic structure adjacent to a second sidewall of the second structure, adjacent to a second sidewall of the third structure and extending the third magnetic structure onto a third portion of the first structure, wherein the third portion is between the second sidewall of the second structure and the second sidewall of the third structure; and
coupling a magnet with the first magnetic structure, the second magnetic structure and the third magnetic structure.
15. The method of claim 14 , wherein forming the first magnetic structure, the second magnetic structure and the third magnetic structure further comprises:
depositing a magnetic material on a first uppermost surface of the first structure;
depositing the magnetic material on a second uppermost surface of the second structure and adjacent to the first sidewall and the second sidewall of the second structure;
depositing the magnetic material on a third uppermost surface of the third structure and adjacent to the first sidewall and the second sidewall of the third structure; and
planarizing and removing the magnetic material from the second uppermost surface and from the third uppermost surface, to form the second structure and the third structure that are substantially coplanar.
16. The method of claim 15 , wherein planarizing and removing the magnetic material further comprises forming the first magnetic structure comprising a fourth uppermost surface, forming the third magnetic structure adjacent to a second sidewall of the second structure comprising a fifth uppermost surface, and wherein the fourth uppermost surface, the fifth uppermost surface and the second uppermost surface are coplanar or substantially coplanar.
17. The method of claim 15 , wherein planarizing and removing the magnetic material further comprises forming the second magnetic structure comprising a sixth uppermost surface, the third magnetic structure adjacent to a second sidewall of the third structure comprising a seventh uppermost surface, and wherein the sixth uppermost surface, the seventh uppermost surface and the third uppermost surface are coplanar or substantially coplanar.
18. The method of claim 15 , wherein forming the first magnetic structure, the second magnetic structure and the third magnetic structure further comprises:
forming the magnetic material on sidewalls of the first structure below the first uppermost surface, and conformally forming a hermetic insulator material on the magnetic material and on uppermost surfaces of the second structure and the third structure.
19. The method of claim 15 , wherein forming the second structure and the third structure further comprises patterning the second non-magnetic material and tapering a respective pair of opposite sidewalls of the second structure and of the third structure.
20. The method of claim 15 , wherein planarizing forms the first magnetic structure comprising a first vertical thickness relative to the first uppermost surface, the second magnetic structure comprising a second vertical thickness relative to the first uppermost surface, and the third magnetic structure comprising a third vertical thickness relative to the first uppermost surface, and wherein the first vertical thickness, the second vertical thickness and the third vertical thickness are substantially identical.
21. The method of claim 14 , wherein forming the second structure comprises patterning the second non-magnetic material to form the first sidewall and the second sidewall of the second structure having a first slope that is less than 90 degrees relative to an uppermost surface of the first structure, and wherein forming the third structure comprises patterning the second non-magnetic material to form the first sidewall and the second sidewall of the third structure having a second slope that is less than 90 degrees relative to the uppermost surface of the first structure.