Micro device transfer head heater assembly and method of transferring a micro device

1. A method of transferring a micro device comprising:

heating a carrier substrate carrying a micro device connected to a bonding layer to a temperature below a liquidus temperature of the bonding layer;

heating a transfer head to a temperature above the liquidus temperature of the bonding layer;

contacting the micro device with a transfer head, wherein heat transfers from the transfer head into the bonding layer to at least partially melt the bonding layer;

applying a voltage to the transfer head to create a grip pressure on the micro device; and

picking up the micro device with the transfer head;

placing the micro device in contact with a receiving substrate; and

releasing the micro device onto the receiving substrate.

2. The method of claim 1 , wherein heating the carrier substrate comprises heating the carrier substrate to a temperature 1° C. to 10° C. below the liquidus temperature of the bonding layer.

3. The method of claim 1 , wherein heating the transfer head comprises heating the transfer head to a temperature 1° C. to 150° C. above the liquidus temperature of the bonding layer.

4. The method of claim 1 , wherein heating the transfer head comprises heating the transfer head to a temperature 1° C. to 50° C. above the liquidus temperature of the bonding layer.

5. The method of claim 1 , wherein the micro device transfer head comprises:

a base substrate;

a mesa structure including sidewalls;

an electrode formed over the mesa structure; and

a dielectric layer covering the electrode.

6. The method of claim 1 , wherein the micro device is a micro LED device comprising:

a micro p-n diode; and

a metallization layer, wherein the metallization layer is between the micro p-n diode and the bonding layer on the carrier substrate.

7. The method of claim 6 , wherein picking up the micro device comprises picking up the micro p-n diode, the metallization layer and a portion of the bonding layer.

8. The method of claim 7 , wherein a conformal dielectric barrier layer spans sidewalls of the micro p-n diode and a bottom surface of the micro p-n diode.

9. The method of claim 8 , further comprising cleaving a portion of the conformal dielectric barrier layer below the bottom surface of the micro p-n diode.

10. The method of claim 1 , further comprising globally heating the receiving substrate.

11. The method of claim 1 , further comprising locally heating the receiving substrate where micro device is released onto the receiving substrate.

12. A method of transferring an array of micro devices comprising:

heating a carrier substrate carrying an array of micro devices connected to a plurality of locations of a bonding layer to a temperature below a liquidus temperature of the bonding layer;

heating an array of transfer heads to a temperature above the liquidus temperature of the bonding layer;

contacting the array of micro devices with the array of transfer heads, wherein heat transfers from the array of transfer heads into the plurality of locations of the bonding layer to at least partially melt portions of the plurality of locations of the bonding layer;

selectively applying a voltage to a portion of the array of transfer heads;

picking up a corresponding portion of the array of micro devices with the portion of the array of transfer heads;

contacting a receiving substrate with the portion of the array of micro devices; and

selectively releasing the portion of the array of micro devices onto at least one receiving substrate.

13. The method of claim 12 , wherein the array of transfer heads comprises:

a base substrate;

an array of mesa structures, each mesa structure including sidewalls and an electrode formed over the mesa structure; and

a dielectric layer covering the array of mesa structures and each electrode formed over each mesa structure.

14. The method of claim 12 , wherein heating the carrier substrate comprises heating the carrier substrate to a temperature 1° C. to 10° C. below the liquidus temperature of the bonding layer.

15. The method of claim 14 , comprising globally heating the plurality of locations of the bonding layer to the temperature 1° C. to 10° C. below the liquidus temperature of the bonding layer.

16. The method of claim 14 , comprising locally heating the plurality of locations of the bonding layer to the temperature 1° C. to 10° C. below the liquidus temperature of the bonding layer.

17. The method of claim 12 , wherein heating the array of transfer heads comprises heating the array of transfer heads to a temperature 1° C. to 150° C. above the liquidus temperature of the bonding layer.

18. The method of claim 12 , wherein heating the array of transfer heads comprises heating the array of transfer heads to a temperature 1° C. to 50° C. above the liquidus temperature of the bonding layer.

19. The method of claim 12 , wherein each micro device in the array of micro devices is a micro LED device comprising:

a micro p-n diode; and

a metallization layer, wherein the metallization layer is between the micro p-n diode and the bonding layer on the carrier substrate.

20. The method of claim 19 , wherein picking up the array of micro devices comprises picking up the micro p-n diode, the metallization layer and a portion of the plurality of locations of the bonding layer for each micro device in the array of micro devices.

21. The method of claim 20 , wherein a conformal dielectric barrier layer spans sidewalls and a bottom surface of each the micro p-n diode.

22. The method of claim 21 , further comprising cleaving a portion of the conformal dielectric barrier layer at a separate location below the bottom surface of each micro p-n diode.

23. The method of claim 12 , further comprising globally heating the receiving substrate.

24. The method of claim 12 , further comprising locally heating the receiving substrate where array of micro device are released onto the receiving substrate.

25. A method of transferring an array of micro devices comprising:

heating a carrier substrate carrying an array of micro devices connected to a plurality of locations of a bonding layer to a temperature below a liquidus temperature of the bonding layer;

heating an array of transfer heads to a temperature above the liquidus temperature of the bonding layer;

contacting the array of micro devices with the array of transfer heads, wherein heat transfers from the array of transfer heads into the plurality of locations of the bonding layer to at least partially melt portions of the plurality of locations of the bonding layer;

applying a voltage to the array of transfer heads;

picking up the array of micro devices with the array of transfer heads;

contacting a receiving substrate with the array of micro devices; and

releasing array of micro devices onto the receiving substrate.

26. The method of claim 25 , wherein the array of transfer heads comprises:

a base substrate;

an array of mesa structures; and

a dielectric layer covering the array of mesa structures.

27. The method of claim 25 , wherein heating the carrier substrate comprises heating the carrier substrate to a temperature 1° C. to 10° C. below the liquidus temperature of the bonding layer.

28. The method of claim 25 , wherein heating the array of transfer heads comprises heating the array of transfer heads to a temperature 1° C. to 150° C. above the liquidus temperature of the bonding layer.

29. The method of claim 25 , wherein heating the array of transfer heads comprises heating the array of transfer heads to a temperature 1° C. to 50° C. above the liquidus temperature of the bonding layer.

30. The method of claim 25 , wherein the plurality of locations of the bonding layer are a plurality of laterally separate locations of the bonding layer.