Source/drain contacts for non-planar transistors
The present description relates to the field of fabricating microelectronic devices having non-planar transistors. Embodiments of the present description relate to the formation of source/drain contacts within non-planar transistors, wherein a titanium-containing contact interface may be used in the formation of the source/drain contact with a discreet titanium silicide formed between the titanium-containing interface and a silicon-containing source/drain structure.
1. An apparatus, comprising:
a fin comprising silicon;
a non-planar gate electrode over at least a portion of the fin;
a first spacer on a first side of the gate electrode;
a second spacer on a second side of the gate electrode;
a first dielectric material, the first spacer being between the gate electrode and at least a portion of the first dielectric material;
a cap dielectric layer above the gate electrode, at least a portion of the first dielectric material being below the cap dielectric layer;
a second dielectric layer above the cap dielectric layer;
a source region at least partially in the fin, the source region comprising silicon and at least one other element;
a silicide region on the source region, the silicide region comprising silicon and titanium and being at least substantially free from nickel;
a source contact that is in contact with at least a portion of the second dielectric layer, at least a portion of the cap dielectric layer, and at least a portion of the first dielectric material, the source contact comprising:
an interface layer on a bottom and sides of the contact, the contact interface layer comprising titanium and nitrogen; and
a contact fill material, the contact fill material comprising tungsten, the interface layer being between at least a portion of the contact fill material and the silicide region at the bottom of the contact, and the interface layer being between at least a portion of the fill material and at least a portion of the first dielectric material at the sides of the contact, and the interface layer further being between at least a portion of the contact fill material and at least a portion of the second dielectric material at the sides of the contact; and
wherein, in at least one cross section through the fin, all of the silicide region is under the source contact.
2. The apparatus of claim 1 , wherein the source region is at least partially in a recess in the fin.
3. The apparatus of claim 1 , wherein the source region comprises a doped region of the fin.
4. The apparatus of claim 1 , wherein the capping layer comprises silicon and nitrogen.
5. The apparatus of claim 1 , wherein the first and second spacers comprise silicon and nitrogen.
6. The apparatus of claim 1 , wherein substantially none of the capping layer is above the first dielectric material.
7. The apparatus of claim 1 , wherein a first side of the source contact that is closest to the gate electrode is in contact with the capping layer and a second side of the source contact opposite the first side is not in contact with the capping layer.
8. The apparatus of claim 1 , wherein the second dielectric material comprises silicon and oxygen.
9. The apparatus of claim 1 , wherein the silicide region does not extend beyond the sides of the source contact.
10. An apparatus, comprising:
a fin comprising silicon;
a non-planar gate electrode over at least a portion of the fin;
a first spacer on a first side of the gate electrode;
a second spacer on a second side of the gate electrode;
a first dielectric material, the first spacer being between the gate electrode and at least a portion of the first dielectric material;
a cap dielectric layer above the gate electrode, at least a portion of the first dielectric material being below the cap dielectric layer;
a second dielectric layer above the cap dielectric layer;
a source region at least partially in the fin, the source region comprising silicon and at least one other element;
a silicide region on the source region, the silicide region comprising silicon and titanium and being at least substantially free from nickel;
a source contact that extends through at least a portion of the second dielectric layer, at least a portion of the first dielectric material, and is in contact with at least a portion of the cap dielectric layer, and at least a portion of the first dielectric material, the source contact including an interface layer comprising titanium and nitrogen and a fill material comprising tungsten interior to the interface layer; and
wherein, in at least one cross section through the fin, substantially all of the silicide region is under the source contact.
11. The apparatus of claim 10 , wherein the source region is at least partially in a recess in the fin.
12. The apparatus of claim 10 , wherein the source region comprises a doped region of the fin.
13. The apparatus of claim 10 , wherein the capping layer comprises silicon and nitrogen.
14. The apparatus of claim 10 , wherein the first and second spacers comprise silicon and nitrogen.
15. The apparatus of claim 10 , wherein substantially none of the capping layer is above the first dielectric material.
16. The apparatus of claim 10 , wherein a first side of the source contact that is closest to the gate electrode is in contact with the capping layer and a second side of the source contact opposite the first side is not in contact with the capping layer.
17. The apparatus of claim 10 , wherein the second dielectric material comprises silicon and oxygen.
18. The apparatus of claim 10 , wherein the silicide region does not extend beyond the sides of the source contact.
19. The apparatus of claim 10 , further comprising:
a drain region at least partially in the fin, the drain region comprising silicon and at least one other element;
a second silicide region on the drain region, the second silicide region comprising silicon and titanium and being at least substantially free from nickel;
a drain contact that extends through at least a portion of the second dielectric layer, at least a portion of the first dielectric material, and is in contact with at least a portion of the cap dielectric layer, and at least a portion of the first dielectric material, the drain contact including an interface layer comprising titanium and nitrogen and a fill material comprising tungsten interior to the interface layer; and
wherein, in at least one cross section through the fin, substantially all of the second silicide region is under the drain contact.