1. A method comprising:
depositing a layer of resist over a first face of a silicon substrate that is heavily doped and using a photolithographic process to produce an annular pattern in the resist;
etching an annular trench into the silicon substrate as defined by the annular pattern;
filling the annular trench with an electrically insulating material and polishing the first face; and
polishing or grinding the faces of the silicon substrate to expose the filled annular trench thereby producing a low resistance connection through the substrate.
2. The method of claim 1 further comprising oxidizing the trench walls before filling the trench with electrically insulating material.
3. The method of claim 1 wherein the etching is reactive ion etching
4. The method of claim 1 further comprising:
creating an oxide layer on the first face of the silicon substrate before photolithographically producing the annular pattern and wherein the annular trench is etched through the oxide layer before it is etched into the silicon substrate.
5. The method of claim 1 wherein the first face of the silicon substrate is the front side of the silicon substrate which is also the polished side.
6. The method of claim 1 wherein the electrically insulating material is oxide.
7. The method of claim 1 further comprising oxidizing the trench walls before filling the trench with oxide.
8. A method comprising:
depositing a layer of resist over a first face of a silicon substrate that is heavily doped and using a photolithographic process to produce an annular pattern in the resist;
etching an annular trench into the silicon substrate as defined by the annular pattern;
creating an electrically insulating layer on the trench walls;
filling the annular trench with a fill material; and
polishing or grinding the faces of the silicon substrate to expose the filled annular trench thereby producing a low resistance connection through the substrate.
9. The method of claim 8 wherein the etching is reactive ion etching.
10. The method of claim 8 further comprising:
creating an oxide layer on the first face of the silicon substrate before photolithographically producing the annular pattern and wherein the annular trench is etched through the oxide layer before it is etched into the silicon substrate.
11. The method of claim 8 wherein the first face of the silicon substrate is the front side of the silicon substrate which is also the polished side.
12. The method of claim 8 wherein the fill material is polysilicon.
13. The method of claim 8 wherein the electrically insulating layer is an oxide layer that is created by oxidation of the trench walls.
14. The method of claim 8 wherein the electrically insulating layer is an oxide layer that is deposited.
15. A system comprising:
a silicon substrate that is heavily doped such that it is electrically conductive;
an annular trench through the silicon substrate wherein the annular trench reaches from one face of the silicon substrate to the other side of the silicon substrate; and
an electrically insulating material arranged in the trench to electrically insulate the inside of the annulus from the outside of the annulus, thereby producing an electrically conductive connection through the substrate.
16. The system of claim 15 wherein the electrically insulating material is oxide.
17. The system of claim 15 wherein the electrically insulating material completely fills the trench.
18. The system of claim 15 wherein the electrically insulating material completely coats at least one trench wall and further comprising a different material filling that portion of the trench that is not filled with the electrically insulating material.
19. The system of 15 wherein the electrically insulating material is oxide and oxide completely fills the trench.
20. The system of claim 15 wherein the electrically insulating material completely coats at least one trench wall and further comprising polysilicon filling that portion of the trench that is not filled with the electrically insulating material.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A magnetic memory device comprising:
a plurality of first metal lines arranged in parallel on a substrate, each of the plurality of first metal lines including a plurality of magnetic domains with variable magnetization directions;
a plurality of second metal lines arranged on the substrate, the plurality of second metal lines being arranged perpendicular to the first metal lines and including tunnels through which the plurality of first metal lines pass;
a plurality of first input units, each first input unit being connected to a corresponding one of the plurality of first metal lines and each of the plurality of first input units supplying a current to move magnetic domains within the corresponding one of the plurality of first metal lines;
a plurality of second input units, each second input unit being connected to a corresponding one of the plurality of second metal lines and each second input unit applying a current to switch magnetization directions of magnetic domains arranged inside the tunnels; and
a plurality of sensing units, each of the plurality of sensing units being connected to a corresponding one of the plurality of second metal lines, and sensing an electromotive force caused by magnetic domain walls passing through the tunnels.
2. The magnetic memory device of claim 1, wherein the substrate is a plastic substrate.
3. The magnetic memory device of claim 1, further including,
a plurality of insulating layers, each of the plurality of insulating layers being interposed between a corresponding one of the plurality of first metal lines and a corresponding one of the plurality of second metal lines.
4. The magnetic memory device of claim 1, wherein each of the plurality of first metal lines is at least one of fin-shaped and formed of a ferromagnetic material.
5. The magnetic memory device of claim 1, wherein, in each of the plurality of first metal lines, a memory area is formed between adjacent tunnels, the memory area including a plurality of magnetic domains.
6. The magnetic memory device of claim 5, wherein the memory area includes a first magnetic domain having a reference magnetization direction, and wherein
when magnetization directions of an (i+1)th magnetic domain and an (i)th magnetic domain are the same, a first data value is recorded, and when magnetization directions of the (i+1)th magnetic domain and the (i)th magnetic domain are different, a second data value is recorded, the first data value and the second data value being different.
7. The magnetic memory device of claim 6, wherein the plurality of magnetic domains formed in the memory area and magnetic domain walls between the plurality of magnetic domains are formed on an end of each of the plurality of first metal lines to control dragging of the magnetic domains, and a magnetic domain wall stopper for stopping the magnetic domain walls is formed on the end of each of the plurality of first metal lines.
8. The magnetic memory device of claim 7, wherein the magnetic domain wall stopper is a notch formed between the magnetic domains.
9. The magnetic memory device of claim 6, wherein the first magnetic domain is formed inside the tunnel.
10. The magnetic memory device of claim 1, wherein a dummy magnetic domain for temporarily changing magnetization direction when information is recorded on other first metal lines is formed on at least one of the plurality of first metal lines.
11. A magnetic memory device comprising:
a plurality of the magnetic memory devices of claim 1 stacked on one another.
12. The magnetic memory device of claim 11, wherein the substrates are plastic substrates.
13. The magnetic memory device of claim 11, further including,
a plurality of insulating layers, each of the plurality of insulating layers being interposed between a corresponding one of the plurality of first metal lines and a corresponding one of the plurality of second metal lines.
14. The magnetic memory device of claim 11, wherein each of the plurality of first metal lines is at least one of fin-shaped and formed of a ferromagnetic material.
15. The magnetic memory device of claim 11, wherein, in each of the plurality of first metal lines, a memory area is formed between adjacent tunnels, the memory area including a plurality of magnetic domains.
16. The magnetic memory device of claim 15, wherein the memory area includes a first magnetic domain having a reference magnetization direction, and wherein
when magnetization directions of an (i+1)th magnetic domain and an (i)th magnetic domain are the same, a first data value is recorded, and when magnetization directions of the (i+1)th magnetic domain and the (i)th magnetic domain are different, a second data value is recorded, the first data value and the second data value being different.
17. The magnetic memory device of claim 16, wherein the plurality of magnetic domains formed in the memory area and magnetic domain walls between the plurality of magnetic domains are formed on an end of each of the plurality of first metal lines to control dragging of the magnetic domains of the memory area, and a magnetic domain wall stopper for stopping the magnetic domain walls is formed on the end of each of the plurality of first metal lines.
18. The magnetic memory device of claim 17, wherein the magnetic domain wall stopper is a notch formed between the plurality of magnetic domains.
19. The magnetic memory device of claim 16, wherein the first magnetic domain is formed inside the tunnel.
20. The magnetic memory device of claim 11, wherein a dummy magnetic domain for temporarily changing magnetization direction when information is recorded on other first metal lines is formed on at least one of the plurality of first metal lines.