Abstract: Provided are approaches for forming a self-aligned via and an air gap within a semiconductor device. Specifically, one approach produces a device having: a first metal line beneath a second metal line within an ultra low-k (ULK) dielectric, the first metal line connected to the second metal line by a first via; a dielectric capping layer formed over the second metal line; a third metal line within first and second via openings formed within a ULK fill material formed over the dielectric capping layer, wherein the third metal line within the first via opening extends to a top surface of the dielectric capping layer, and wherein the third metal line within the second via opening is connected to the second metal by a second via passing through the dielectric capping layer; and an air gap formed between the third metal line within the first and seconds via openings.

Abstract: Provided are approaches for forming a self-aligned via and an air gap within a semiconductor device. Specifically, one approach produces a device having: a first metal line beneath a second metal line within an ultra low-k (ULK) dielectric, the first metal line connected to the second metal line by a first via; a dielectric capping layer formed over the second metal line; a third metal line within first and second via openings formed within a ULK fill material formed over the dielectric capping layer, wherein the third metal line within the first via opening extends to a top surface of the dielectric capping layer, and wherein the third metal line within the second via opening is connected to the second metal by a second via passing through the dielectric capping layer; and an air gap formed between the third metal line within the first and seconds via openings.

Abstract: Embodiments of the present invention provide a method for cuts of sacrificial metal lines in a back end of line structure. Sacrificial Mx+1 lines are formed above metal Mx lines. A line cut lithography stack is deposited and patterned over the sacrificial Mx+1 lines and a cut cavity is formed. The cut cavity is filled with dielectric material. A selective etch process removes the sacrificial Mx+1 lines, preserving the dielectric that fills in the cut cavity. Precut metal lines are then formed by depositing metal where the sacrificial Mx+1 lines were removed. Thus embodiments of the present invention provide precut metal lines, and do not require metal cutting. By avoiding the need for metal cutting, the risks associated with metal cutting are avoided.

Abstract: Embodiments of the present invention provide improved methods of contact formation. A self aligned contact scheme with reduced lithography requirements is disclosed. This reduces the risk of shorts between source/drains and gates, while providing improved circuit density. Cavities are formed adjacent to the gates, and a fill metal is deposited in the cavities to form contact strips. A patterning mask is then used to form smaller contacts by performing a partial metal recess of the contact strips.

Abstract: Embodiments of the present invention provide a semiconductor structure for BEOL (back end of line) integration. A directed self assembly (DSA) material is deposited and annealed to form two distinct phase regions. One of the phase regions is selectively removed, and the remaining phase region serves as a mask for forming cavities in an underlying layer of metal and/or dielectric. The process is then repeated to form complex structures with patterns of metal separated by dielectric regions.

Abstract: An improved semiconductor structure and methods of fabrication that provide improved transistor contacts in a semiconductor structure are provided. A first block mask is formed over a portion of the semiconductor structure. This first block mask covers at least a portion of at least one source/drain (s/d) contact location. An s/d capping layer is formed over the s/d contact locations that are not covered by the first block mask. This s/d capping layer is comprised of a first capping substance. Then, a second block mask is formed over the semiconductor structure. This second block mask exposes at least one gate location. A gate capping layer, which comprises a second capping substance, is removed from the exposed gate location(s). Then a metal contact layer is deposited, which forms a contact to both the s/d contact location(s) and the gate contact location(s).

Abstract: Embodiments of the present invention provide a method for self-aligned metal cuts in a back end of line structure. Sacrificial Mx+1 lines are formed above metal Mx lines. Spacers are formed on each Mx+1 sacrificial line. The gap between the spacers is used to determine the location and thickness of cuts to the Mx metal lines. This ensures that the Mx metal line cuts do not encroach on vias that interconnect the Mx and Mx+1 levels. It also allows for reduced limits in terms of via enclosure rules, which enables increased circuit density.

Abstract: Embodiments of the present invention provide a method for cuts of sacrificial metal lines in a back end of line structure. Sacrificial Mx+1 lines are formed above metal Mx lines. A line cut lithography stack is deposited and patterned over the sacrificial Mx+1 lines and a cut cavity is formed. The cut cavity is filled with dielectric material. A selective etch process removes the sacrificial Mx+1 lines, preserving the dielectric that fills in the cut cavity. Precut metal lines are then formed by depositing metal where the sacrificial Mx+1 lines were removed. Thus embodiments of the present invention provide precut metal lines, and do not require metal cutting. By avoiding the need for metal cutting, the risks associated with metal cutting are avoided.

Abstract: Embodiments of the present invention provide an improved semiconductor structure and methods of fabrication that provide transistor contacts that are self-aligned in two dimensions. Two different capping layers are used, each being comprised of a different material. The two capping layers are selectively etchable to each other. One capping layer is used for gate coverage while the other capping layer is used for source/drain coverage. Selective etch processes open the desired gates and source/drains, while block masks are used to cover elements that are not part of the connection scheme. A metallization line (layer) is deposited, making contact with the open elements to provide electrical connectivity between them.

Abstract: Embodiments of the present invention provide a method for cuts of sacrificial metal lines in a back end of line structure. Sacrificial Mx+1 lines are formed above metal Mx lines. A line cut lithography stack is deposited and patterned over the sacrificial Mx+1 lines and a cut cavity is formed. The cut cavity is filled with dielectric material. A selective etch process removes the sacrificial Mx+1 lines, preserving the dielectric that fills in the cut cavity. Precut metal lines are then formed by depositing metal where the sacrificial Mx+1 lines were removed. Thus embodiments of the present invention provide precut metal lines, and do not require metal cutting. By avoiding the need for metal cutting, the risks associated with metal cutting are avoided.

Abstract: Embodiments of the present invention provide improved methods of contact formation. A self aligned contact scheme with reduced lithography requirements is disclosed. This reduces the risk of shorts between source/drains and gates, while providing improved circuit density. Cavities are formed adjacent to the gates, and a fill metal is deposited in the cavities to form contact strips. A patterning mask is then used to form smaller contacts by performing a partial metal recess of the contact strips.

Abstract: Embodiments of the present invention provide an improved semiconductor structure and methods of fabrication that provide transistor contacts that are self-aligned in two dimensions. Two different capping layers are used, each being comprised of a different material. The two capping layers are selectively etchable to each other. One capping layer is used for gate coverage while the other capping layer is used for source/drain coverage. Selective etch processes open the desired gates and source/drains, while block masks are used to cover elements that are not part of the connection scheme. A metallization line (layer) is deposited, making contact with the open elements to provide electrical connectivity between them.

Abstract: Embodiments of the present invention provide a semiconductor structure for BEOL (back end of line) integration. A directed self assembly (DSA) material is deposited and annealed to form two distinct phase regions. One of the phase regions is selectively removed, and the remaining phase region serves as a mask for forming cavities in an underlying layer of metal and/or dielectric. The process is then repeated to form complex structures with patterns of metal separated by dielectric regions.

Abstract: Embodiments of the present invention provide an improved semiconductor structure and methods of fabrication that provide transistor contacts that are self-aligned in two dimensions. Two different capping layers are used, each being comprised of a different material. The two capping layers are selectively etchable to each other. One capping layer is used for gate coverage while the other capping layer is used for source/drain coverage. Selective etch processes open the desired gates and source/drains, while block masks are used to cover elements that are not part of the connection scheme. A metallization line (layer) is deposited, making contact with the open elements to provide electrical connectivity between them.

Abstract: Embodiments of the present invention provide a semiconductor structure for BEOL (back end of line) integration. A directed self assembly (DSA) material is deposited and annealed to form two distinct phase regions. One of the phase regions is selectively removed, and the remaining phase region serves as a mask for forming cavities in an underlying layer of metal and/or dielectric. The process is then repeated to form complex structures with patterns of metal separated by dielectric regions.

Abstract: Embodiments of the present invention provide improved methods of contact formation. A self aligned contact scheme with reduced lithography requirements is disclosed. This reduces the risk of shorts between source/drains and gates, while providing improved circuit density. Cavities are formed adjacent to the gates, and a fill metal is deposited in the cavities to form contact strips. A patterning mask is then used to form smaller contacts by performing a partial metal recess of the contact strips.

Abstract: During processing of a semiconductor wafer bearing a structure including a low-k dielectric layer, a cap layer and the metal-diffusion barrier layer, a chemical mechanical polishing method applied to remove the metal-diffusion barrier material involves two phases. In the second phase of the barrier-CMP method, when the polishing interface is close to the low-k dielectric material, the polishing conditions are changed so as to be highly selective, producing a negligible removal rate of the low-k dielectric material. The polishing conditions can be changed in a number of ways including: changing parameters of the composition of the barrier slurry composition, and mixing an additive into the barrier slurry.

Abstract: A polishing pad (34) with a poromeric structure polishes two dissimilar materials (56, 58). By using a relatively softer pad. and conditioning, relatively constant times can be used for polishing the dissimilar materials (56, 58). This makes polishing more predictable and increases the number of substrates that can be polished using a single polishing pad (34). Polishing pads (34) are typically changed when other maintenance is performed on the polisher rather than when the polishing rate becomes too low.

Abstract: A chemical-mechanical-polishing (CMP) process in which a metal interconnect material (47) is polished to form a metal plug (48) includes the application of titanium to the surface of a polishing pad (14) of a polishing apparatus (10). Titanium metal is applied to the surface of the polishing pad (14) by either abrasively applying titanium by use of a titanium block (32) attached to a rotating disk (26), or by a titanium body (23, 25) integrated with a carrier ring (23). Alternatively, titanium can be applied by impregnating a felt layer (52) with titanium particles (56), or by adding titanium directly to the polishing slurry (50).

Abstract: A selective cleaning process for fabricating a semiconductor device includes the steps of processing a semiconductor substrate (10) and introducing metal contaminants (22) by contacting the semiconductor substrate (10) with a polishing slurry during a polished planarization process. The metal contaminants (22) are removed by applying a cleaning solution including an organic solvent and a compound containing fluorine. The chemical constituents of the cleaning solution are substantially unreactive with metal interconnect material (12) underlying dielectric layers (18) present on the semiconductor substrate (10). The preferred cleaning solution comprises an aqueous solution of ethylene glycol and ammonium fluoride.