Micro device transfer head array with metal electrodes
A monopolar and bipolar micro device transfer head array and method of forming a monopolar and bipolar micro device transfer array are described. In an embodiment, a micro device transfer head array includes a base substrate, a first insulating layer formed over the base substrate, and an array of mesa structures. A second insulating layer may be formed over the mesa structure, a patterned metal layer over the second insulating layer, and a dielectric layer covering the metal layer.
1. A micro device transfer head array, comprising:
a base substrate;
a first insulating layer on the base substrate;
an array of electrostatic transfer heads, each electrostatic transfer head including a mesa structure over the first insulating layer, wherein each mesa structure has a maximum width of 1 to 100 μm;
a second insulating layer over a top surface of each of the mesa structures;
a patterned metal layer over the second insulating layer and the top surface of each of the mesa structures;
a through via extending through the base substrate; and
a dielectric layer covering the patterned metal layer on the top surface of each of the mesa structures.
2. The micro device transfer head array of claim 1 , further comprising an insulating layer covering a side surface of the through via.
3. The micro device transfer head array of claim 1 , further comprising a conductive layer within the through via and in electrical connection with the patterned metal layer.
4. The micro device transfer head array of claim 3 , wherein the conductive layer does not completely fill the through via.
5. The micro device transfer head array of claim 3 , wherein the patterned metal layer comprises an array of electrode leads electrically connected with an array of metal electrodes corresponding to the array of electrostatic transfer heads.
6. The micro device transfer head array of claim 5 , wherein each metal electrode completely covers a top surface of a corresponding mesa structure.
7. The micro device transfer head array of claim 1 , further comprising a second through via extending through the base substrate.
8. The micro device transfer head array of claim 7 , further comprising a second conductive layer within the second through via and in electrical connection with the patterned metal layer.
9. The micro device transfer head array of claim 8 , wherein the patterned metal layer comprises:
a first array of electrode leads electrically connected with a first array of metal electrodes corresponding to the array of electrostatic transfer heads; and
a second array of electrode leads electrically connected with a second array of metal electrodes corresponding to the array of electrostatic transfer heads;
wherein the first and second arrays of metal electrodes are directly over the top surfaces of the corresponding mesa structures of the array of electrostatic transfer heads, and the first and second arrays of metal electrodes are electrically isolated from each other.
10. The micro device transfer head array of claim 1 , wherein the dielectric layer is formed of a high-k dielectric material.
11. A micro device transfer head array, comprising:
a base substrate;
a first insulating layer over the base substrate;
an array of electrostatic transfer heads, each electrostatic transfer head including a mesa structure over the first insulating layer, wherein each mesa structure has a maximum width of 1 to 100 μm;
a second insulating layer over the array of mesa structures;
a patterned metal layer over the second insulating layer and a top surface of each of the mesa structures; and
a dielectric layer covering the patterned metal layer on the top surface of each of the mesa structures.
12. The micro device transfer head array of claim 11 , wherein the patterned metal layer further comprises an array of electrode leads electrically connected with an array of metal electrodes.
13. The micro device transfer head array of claim 12 , wherein the array of electrode leads is electrically connected with a metal interconnect.
14. The micro device transfer head array of claim 11 , further comprising a through via extending through the base substrate.
15. The micro device transfer head array of claim 14 , further comprising an insulating layer covering a side surface of the through via.
16. The micro device transfer head array of claim 15 , further comprising a conductive layer within the through via and in electrical connection with the patterned metal layer.
17. The micro device transfer head array of claim 16 , wherein the conductive layer does not completely fill the through via.
18. The micro device transfer head array of claim 11 , wherein the first insulating layer is a buried oxide layer.
19. The micro device transfer head array of claim 18 , wherein the patterned metal layer comprises an array of electrode leads electrically connected with an array of metal electrodes corresponding to the array of electrostatic transfer heads.
20. The micro device transfer head array of claim 19 , wherein each metal electrode completely covers the top surface of a corresponding mesa structure.
21. The micro device transfer head array of claim 11 , wherein the dielectric layer is formed of a high-k dielectric material.