Fabrication of self-aligned gate contacts and source/drain contacts directly above gate electrodes and source/drains
A method of forming an active device having self-aligned source/drain contacts and gate contacts, including, forming an active area on a substrate, where the active area includes a device channel; forming two or more gate structures on the device channel; forming a plurality of source/drains on the active area adjacent to the two or more gate structures and device channel; forming a protective layer on the surfaces of the two or more gate structures, plurality of source/drains, and active layer; forming an interlayer dielectric layer on the protective layer; removing a portion of the interlayer dielectric and protective layer to form openings, where each opening exposes a portion of one of the plurality of source/drains; forming a source/drain contact liner in at least one of the plurality of openings; and forming a source/drain contact fill on the source/drain contact liner.
1. An active device having self-aligned source/drain contacts and gate contacts, comprising:
an active area on a substrate, where the active area includes a device channel;
two or more gate structures on the active area;
a plurality of source/drains on the active area, wherein each source/drain is adjacent to at least one of the two or more gate structures;
gate sidewall spacer on the side surfaces of each of the two or more gate structures;
a protective layer on each of the gate sidewall spacers;
a source/drain contact liner on at least a portion of each of the plurality of source/drains, wherein the protective layer is between the source/drain contact liner and at least one of the two or more gate structures;
a gate contact on each of the two or more gate structures;
a source/drain contact fill on the source/drain contact liner, wherein the locations of the source/drain contact fills are staggered with the gate contacts to form a two-dimensional grid;
a source/drain contact cap on the source/drain contact fill and source/drain contact liner; and
a source/drain contact terminal fill offset from a center section of the gate structures and the gate contacts.
2. The active device of claim 1 , further comprising a separate inner spacer on each of the source/drain contact liners.
3. The active device of claim 2 , wherein each of the two or more gate structures includes a gate dielectric layer, a conductive gate fill, and a work function layer within the gate sidewall spacer.
4. The active device of claim 3 , wherein the inner spacers are silicon nitride (SiN), silicon oxynitride (SiON), a low-k dielectric, a high-k dielectric, silicon borocarbonitride (SiBCN), silicon oxycarbide (SiOC), silicon boro oxycarbide (SIBOC), or combinations thereof.
5. The active device of claim 4 , wherein the source/drain contact liner is a metal nitride.
6. The active device of claim 3 , further comprising a gate contact liner on at least a portion of the conductive gate fill of at least one of the two or more gate structures.
7. The active device of claim 6 , further comprising a gate contact layer on each gate contact liner.
8. The active device of claim 7 , wherein the gate contact liner is a metal nitride.
9. The active device of claim 8 , wherein the gate contact liner is titanium nitride (TiN), titanium aluminum nitride (TiAlN), hafnium nitride (HfN), hafnium silicon nitride (HfSiN), tantalum nitride (TaN), tantalum silicon nitride (TaSiN), tungsten nitride (WN), molybdenum nitride (MoN), niobium nitride (NbN), or combinations thereof.
10. An active device having self-aligned source/drain contacts and gate contacts, comprising:
an active area on a substrate, where the active area includes a device channel;
two or more gate structures on the device channel;
a plurality of source/drains on the active area, where in each of the plurality of source/drains is adjacent to at least one of the two or more gate structures;
a protective layer on the side surfaces of each of the gate sidewall spacers;
an interlayer dielectric layer on the protective layer;
a source/drain contact liner on each of the plurality of source/drains and at least a portion of the protective layer;
a gate contact on each of the two or more gate structures;
a source/drain contact fill on the source/drain contact liner;
a source/drain contact cap on the source/drain contact fill and source/drain contact liner; and
a source/drain contact terminal fill offset from a center section of the gate structures and the gate contacts, wherein the gate contacts and source/drain terminal fills are diagonally displaced from each other.
11. The active device of claim 10 , wherein the protective layer has a thickness in the range of about 4 nm to about 15 nm.
12. The active device of claim 11 , wherein the gate sidewall spacer has a thickness in the range of about 4 nm to about 15 nm.
13. The active device of claim 10 , further comprising a gate contact liner and gate contact layer on at least a portion of the two or more gate structures, and a separate source/drain contact terminal layer on each of the inner spacers and a source/drain contact fill on the source/drain contact terminal layer.
14. The active device of claim 13 , wherein the gate contact layer is tungsten (W), titanium (Ti), molybdenum (Mo), cobalt (Co), a conductive carbon material, or a suitable combinations thereof.