Globalfoundries Inc.

Andy Chih-Hung Wei

Guillaume Bouche

Mark Alexander Zaleski

Jason Eugene Stephens

Tuhin Guha Neogi

Xiang Hu

Dae Geun Yang

Jongwook Kye

Jia Zeng

Jing Wan

Dae-han Choi

Mariappan Hariharaputhiran

Gabriel Padron Wells

Jagar Singh

Andre P Labonte

Huy Cao

Sandeep Gaan

Jerome F Wandell

Konstantin G Korablev

Embodiments of the present invention provide a multiple fin field effect transistor (finFET) with low-resistance gate structure. A metallization line is formed in parallel with the gate, and multiple contacts are formed over the fins which connect the metallization line to the gate. The metallization line provides reduced gate resistance, which allows fewer transistors to be used for providing In-Out (IO) functionality, thereby providing space savings that enable an increase in circuit density.

Multiple fin finFET with low-resistance gate structure

Provided are approaches for forming merged gate and source/drain (S/D) contacts in a semiconductor device. Specifically, one approach provides a dielectric layer over a set of gate structures formed over a substrate; a set of source/drain (S/D) openings patterned in the dielectric layer between the gate structures; a fill material formed over the gate structures, including within the S/D openings; and a set of gate openings patterned over the gate structures, wherein a portion of the dielectric layer directly adjacent the fill material formed within one of the S/D openings is removed. The fill material is then removed, selective to the dielectric layer, and a metal material is deposited over the semiconductor device to form a set of gate contacts within the gate openings, and a set of S/D contacts within the S/D openings, wherein one of the gate contacts and one of the S/D contacts are merged.

Merged gate and source/drain contacts in a semiconductor device

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.

Precut metal lines

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.

Transistor contacts self-aligned in two dimensions

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.

Self-aligned via and air gap

Embodiments of the present invention provide methods of removing fin portions from a finFET. At a starting point, a high-K dielectric layer is disposed on a substrate. A fin hardmask and lithography stack is deposited on the high-k dielectric. A fin hardmask is exposed, and a first portion of the fin hardmark is removed. The lithography stack is removed. A second portion of the fin hardmask is removed. Fins are formed. A gap fill dielectric is deposited and recessed.

Semiconductor structure having gap fill dielectric layer disposed between fins

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.

Self-aligned back end of line cut

Approaches for altering the threshold voltage (e.g., to zero threshold voltage) in a fin-type field effect transistor (FinFET) device are provided. In embodiments of the invention, a first N+ region and a second N+ region are formed on a finned substrate that has a p-well construction. A region of the finned substrate located between the first N+ region and the second N+ region is doped with a negative implant species to form an n-well. The size and/or composition of this n-well region can be adjusted in view of the existing p-well construction of the substrate device to change the threshold voltage of the FinFET device (e.g., to yield a zero threshold voltage FinFET device).

Split well zero threshold voltage field effect transistor for integrated circuits

Transistor contacts self-aligned two dimensions

Provided are approaches for forming gate and source/drain (S/D) contacts. Specifically, a gate contact opening is formed over at least one of a set of gate structures, a set of S/D contact openings is formed over fins of the semiconductor device, and a metal material is deposited over the semiconductor device to form a gate contact within the gate contact opening and a set of S/D contacts within the set of S/D contact openings. In one approach, nitride remains between the gate contact and at least one of the S/D contacts. In another approach, the device includes merged gate and S/D contacts. This approach provides selective etching to partition areas where oxide will be further removed selectively to nitride to create cavities to metallize and create contact to the S/D, while isolation areas between contact areas are enclosed in nitride and do not get removed during the oxide etch.

Self-aligned gate contact formation

Embodiments of the present invention provide a metal gate structure and method of formation. In the replacement metal gate (RMG) process flow, the gate cut process is performed after the metal gate is formed. This allows for a reduced margin between the end of the gate and an adjacent fin. It enables a thinner sacrificial layer on top of the dummy gate, since the gate cut step is deferred. The thinner sacrificial layer improves device quality by reducing the adverse effect of shadowing during implantation. Furthermore, in this process flow, the work function metal layer is terminated along the semiconductor substrate by a capping layer, which reduces undesirable shifts in threshold voltage that occurred in prior methods and structures.

Metal gate structure and method of formation

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).

Growing community of inventors

Queensbury, NY, United States of America

Andy Chih-Hung Wei