Metal-insulator-semiconductor tunneling contacts having an insulative layer disposed between source/drain contacts and source/drain regions
A contact to a source or drain region. The contact has a conductive material, but that conductive material is separated from the source or drain region by an insulator.
1. A device, comprising:
a transistor with a source region and a drain region;
a first interlayer dielectric layer adjacent the transistor;
a trench through the first interlayer dielectric layer to the source region; and
a conductive source contact in the trench, the source contact being separated from the source region by an insulating layer.
2. The device of claim 1 , wherein the transistor is a multigate transistor including a fin.
3. The device of claim 2 , wherein the insulating layer is on a top surface and side walls of the fin.
4. The device of claim 1 , wherein the insulating layer has a thickness of about 4 nanometers or less.
5. The device of claim 1 , further comprising:
a second interlayer dielectric layer;
a first metallization layer adjacent the second interlayer dielectric layer and having a plurality of conductive vias and a plurality of conductive lines;
a third interlayer dielectric layer over the second interlayer dielectric layer;
a second metallization layer adjacent the third interlayer dielectric layer and having a plurality of conductive vias and a plurality of conductive lines; and
wherein at least some of the plurality of conductive vias and the plurality of conductive lines of the first metallization layer and at least some of the plurality of conductive vias and the plurality of conductive lines of the second metallization layer are conductively connected to the conductive source contact.
6. The device of claim 1 , wherein the conductive source contact has a thickness of less than 100 nanometers.
7. The device of claim 6 , further comprising a fill conductor on the conductive source contact and substantially filling the trench.
8. The device of claim 1 , wherein the transistor is a P-type transistor and the conductive source contact comprises a metal with a workfunction above about 5 eV.
9. The device of claim 1 , wherein the transistor is an N-type transistor and the conductive source contact comprises a metal with a workfunction below about 3.2 eV.
10. The device of claim 1 , wherein the conductive source contact comprises Al or Ni.
11. A device, comprising:
a transistor with a source region and a drain region;
a source contact, wherein the source contact is not directly adjacent the source region, and wherein a first insulating layer separates the source contact from the source region; and
a drain contact wherein the drain contact is not directly adjacent the drain region, and wherein a second insulating layer separates the drain contact from the drain region.
12. The device of claim 11 , wherein the transistor is a multigate transistor, the source region has a top and side walls, and the drain region has a top and side walls.
13. The device of claim 11 , where neither the source contact nor the drain contact comprises a silicide.
14. The device of claim 11 , wherein the first and second insulating layer comprise HfO 2 .
15. The device of claim 11 , wherein the transistor has a channel region that comprises a group III-V material.