Method of forming a gate contact structure and source/drain contact structure for a semiconductor device
One illustrative method disclosed includes, among other things, forming a sacrificial S/D contact structure above an S/D region of a transistor device, removing at least a portion of a gate cap and at least a portion of a gate sidewall spacer to define a gate contact cavity that is positioned entirely above the active region and exposes an upper surface of a gate structure of the transistor device, and forming an internal sidewall spacer within the gate contact cavity. The method also includes performing at least one process operation to remove at least the sacrificial S/D contact structure and define a S/D contact cavity, and forming a gate contact structure within the gate contact cavity that is conductively coupled to the gate structure and forming a S/D contact structure within the S/D contact cavity that is conductively coupled to the S/D region.
1. A method of forming a gate contact for a gate structure of a transistor device formed above an active region defined in a semiconductor substrate, said transistor device comprising a source/drain (S/D) region, a gate structure having a gate cap positioned above said gate structure and a gate sidewall spacer positioned adjacent said gate structure, the method comprising:
forming a sacrificial S/D contact structure above said S/D region;
removing at least a portion of said gate cap and at least a portion of said gate sidewall spacer to define a gate contact cavity that is positioned entirely above said active region, wherein said gate contact cavity exposes an upper surface of said gate structure and a sidewall surface of said sacrificial S/D contact structure;
forming an internal sidewall spacer within said gate contact cavity and contacting said sidewall surface of said sacrificial S/D contact structure;
after forming said internal sidewall spacer, performing at least one process operation to remove at least said sacrificial S/D contact structure and define an S/D contact cavity and expose said S/D region;
forming a gate contact structure within said gate contact cavity that is conductively coupled to said gate structure; and
forming a S/D contact structure within said S/D contact cavity that is conductively coupled to said S/D region, wherein a portion of said internal sidewall spacer within said gate contact cavity is positioned between said gate contact structure and said S/D contact structure.
2. The method of claim 1 , wherein forming said sacrificial S/D contact structure above said S/D region comprises:
depositing a layer of sacrificial material comprising one of polysilicon or amorphous silicon above said S/D region and proximate said gate sidewall spacer; and
performing a chemical mechanical polishing (CMP) process to remove excess portions of said layer of sacrificial material positioned above said gate cap.
3. The method of claim 1 , wherein forming said internal sidewall spacer within said gate contact cavity comprises:
performing a conformal deposition process to form a layer of internal spacer material above said sacrificial S/D contact structure and within said gate contact cavity; and
performing an anisotropic etching process on said layer of internal spacer material to thereby define said internal sidewall spacer positioned on an entire inner perimeter of said gate contact cavity.
4. The method of claim 1 , wherein performing said at least one process operation to remove at least said sacrificial S/D contact structure and define said S/D contact cavity and expose said S/D region comprises:
performing a first etching process to remove said sacrificial S/D contact structure from above a protective layer formed on and in contact with said S/D region; and
performing a second etching process to remove said protective layer from above said S/D region.
5. The method of claim 1 , wherein said internal sidewall spacer within said gate contact cavity extends around an entire outer perimeter of said gate contact structure.
6. The method of claim 1 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises
depositing one or more layers of metal-containing material in said gate contact cavity and in said S/D contact cavity; and
performing at least one chemical mechanical polishing (CMP) process to remove portions of said deposited layers of metal-containing material positioned outside of said gate contact cavity and outside of said S/D contact cavity above said gate cap.
7. The method of claim 6 , wherein said one or more layers of metal-containing material comprise one of tungsten, cobalt, titanium, tantalum, titanium nitride, tantalum nitride or copper.
8. The method of claim 1 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises forming said gate contact structure and said S/D contact structure from a same conductive material.
9. The method of claim 1 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises forming said gate contact structure and said S/D contact structure such that an upper surface of said gate contact structure and an upper surface of said S/D contact structure are substantially co-planar with an upper surface of said gate cap.
10. The method of claim 1 , further comprising:
forming a layer of insulating material above said gate contact structure and above said S/D contact structure; and
forming first and second V 0 contacts within said layer of insulating material, wherein said first V 0 contact is conductively coupled to said gate contact structure and said second V 0 contact is conductively coupled to said S/D contact structure.
11. The method of claim 1 , wherein said transistor device is one of a FinFET transistor device or a planar transistor device.
12. The method of claim 1 , wherein said S/D region comprises an epitaxially grown semiconductor material and wherein said S/D contact structure is formed on and in contact with said epitaxially grown semiconductor material.
13. The method of claim 1 , wherein said transistor device comprises a second source/drain (S/D) region, the method further comprises:
forming a second sacrificial S/D contact structure above said second S/D region;
performing the at least one process operation comprises removing at least said second sacrificial S/D contact structure to define a second S/D contact cavity and expose said second S/D region;
forming a second S/D contact structure within said second S/D contact cavity that is conductively coupled to said second S/D region; and
forming the gate contact structure within said gate contact cavity such that the gate contact structure is further conductively coupled to second S/D contact structure.
14. A method of forming a gate contact for a gate structure of a transistor device formed above an active region defined in a semiconductor substrate, said transistor device comprising a source/drain (S/D) region, a gate structure having a gate cap positioned above said gate structure and a gate sidewall spacer positioned adjacent said gate structure, the method comprising:
forming a protective layer above said S/D region;
forming a sacrificial S/D contact structure above said protective layer on said S/D region;
removing at least a portion of said gate cap and at least a portion of said gate sidewall spacer to define a gate contact cavity that is positioned entirely above said active region and exposes an upper surface of said gate structure;
forming an internal sidewall spacer within said gate contact cavity;
after forming said internal sidewall spacer, performing at least one process operation to define an S/D contact cavity and expose said S/D region, wherein performing said at least one process operation comprises:
performing a first etching process to remove said sacrificial S/D contact structure from above said protective layer; and
performing a second etching process to remove said protective layer from above said S/D region;
forming a gate contact structure within said gate contact cavity that is conductively coupled to said gate structure; and
forming a S/D contact structure within said S/D contact cavity that is conductively coupled to said S/D region, wherein said internal sidewall spacer is positioned within said gate contact cavity and around an entire outer perimeter of said gate contact structure and wherein a portion of said internal spacer is positioned between said gate contact structure and said S/D contact structure.
15. The method of claim 14 , wherein forming said protective layer above said S/D region comprises forming said protective layer on and in contact with said S/D region.
16. The method of claim 14 , wherein forming said sacrificial S/D contact structure above said protective layer comprises forming said sacrificial S/D contact structure on and in contact with said protective layer.
17. The method of claim 14 , wherein forming said internal sidewall spacer within said gate contact cavity comprises:
performing a conformal deposition process to form a layer of internal spacer material above said sacrificial S/D contact structure and within said gate contact cavity; and
performing an anisotropic etching process on said layer of internal spacer material to thereby define said internal sidewall spacer within an entire inner perimeter of said gate contact cavity.
18. The method of claim 14 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises:
depositing one or more layers of metal-containing material in said gate contact cavity and in said S/D contact cavity;
performing at least one chemical mechanical polishing (CMP) process to remove portions of said deposited layers of metal-containing material positioned outside of said gate contact cavity and outside of said S/D contact cavity above said gate cap.
19. The method of claim 14 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises forming said gate contact structure and said S/D contact structure from a same conductive material.
20. The method of claim 14 , wherein forming said gate contact structure within said gate contact cavity and forming said S/D contact structure within said S/D contact cavity comprises forming said gate contact structure and forming said S/D contact structure such that an upper surface of said gate contact structure and an upper surface of said S/D contact structure are substantially co-planar with an upper surface of said gate cap.