Intel Corporation

Intel Ndtm US LLC

Andy Chih-Hung Wei

Guillaume Bouche

Sean T Ma

Mohit K Haran

Charles Henry Wallace

Changyok Park

Piyush Mohan Sinha

Yang-Chun Cheng

Jack T Kavalieros

Tahir Ghani

Anand S Murthy

Mauro J Kobrinsky

Leonard P Guler

Dax M Crum

Shaestagir Chowdhury

Sukru Yemenicioglu

Hyuk Ju Ryu

Mwilwa Tambwe

Techniques are provided herein to form semiconductor devices having gate tie-down structures between the device gate and a buried/backside power rail (BPR). In an example, a semiconductor device includes a conductive material that is part of a transistor gate structure on a semiconductor region. The semiconductor region can be, for example, a fin or a set of one or more nanowires or nanoribbons that extends between a source region and a drain region. A BPR structure is beneath a dielectric layer that is between the BPR structure and the conductive material of the gate structure. A portion of the conductive material also extends through the dielectric material to provide a conductive via between the gate structure and the underlying BPR structure. The conductive material may be, for example, work function and/or metal fill material of the gate electrode of the gate structure.

Gate tie structures to buried or backside power rails

A structure includes a first vertical stack of horizontal nanowires having a first width. A second vertical stack of horizontal nanowires is spaced apart from and parallel with the first vertical stack of horizontal nanowires and has the first width. A first gate structure includes a first gate structure portion over the first vertical stack of horizontal nanowires, a second gate structure portion over the second vertical stack of horizontal nanowires, and a gate cut between the first gate structure portion and the second gate structure portion. A third vertical stack of horizontal nanowires has a second width greater than the first width. A fourth vertical stack of horizontal nanowires is spaced apart from and parallel with the third vertical stack of horizontal nanowires and has the second width. A second gate structure is continuous over the third vertical stack of horizontal nanowires and over the fourth vertical stack of horizontal nanowires.

Integrated circuit structures having maximized channel sizing

Gate-all-around integrated circuit structures having germanium-diffused nanowire/nanoribbon channel structures, and methods of fabricating gate-all-around integrated circuit structures having germanium-diffused nanowire/nanoribbon channel structures, are described. For example, an integrated circuit structure includes a vertical arrangement of nanowires above a sub-fin structure, wherein individual ones of the vertical arrangement of nanowires include silicon and germanium, and wherein the sub-fin structure has a relatively higher germanium concentration at a top of the sub-fin structure than at a bottom of the sub-fin structure.

Gate-all-around integrated circuit structures having germanium-diffused nanoribbon channel structures

Techniques are provided herein to form semiconductor devices having different work function metals over different devices. The techniques can be used in any number of integrated circuit applications and are particularly useful with respect to gate-all-around (GAA) transistors. In an example, neighboring semiconductor devices each include a different work function to act as the device gate electrode for each semiconductor device. More specifically, a first semiconductor device may be a p-channel GAA transistor with a first work function metal around the various nanoribbons of the transistor, while the second neighboring semiconductor device may be an n-channel GAA transistor with a second work function metal around the various nanoribbons of the transistor. No portions of the first work function metal are present around the nanoribbons of the second semiconductor device and no portions of the second work function metal are present around the nanoribbons of the first semiconductor device.

Dual metal gate structures on nanoribbon semiconductor devices

Disclosed herein are source/drain regions in integrated circuit (IC) structures, as well as related methods and components. For example, in some embodiments, an IC structure may include: an array of channel regions, including a first channel region and an adjacent second channel region; a first source/drain region proximate to the first channel region; a second source/drain region proximate to the second channel region; and an insulating material region at least partially between the first source/drain region and the second source/drain region.

Source/drain regions in integrated circuit structures

Discussed herein is gate spacing in integrated circuit (IC) structures, as well as related methods and components. For example, in some embodiments, an IC structure may include: a first gate metal having a longitudinal axis; a second gate metal, wherein the longitudinal axis of the first gate metal is aligned with a longitudinal axis of the second gate metal; a first dielectric material continuously around the first gate metal; and a second dielectric material continuously around the second gate metal, wherein the first dielectric material and the second dielectric material are present between the first gate metal and the second gate metal.

Gate spacing in integrated circuit structures

An example IC structure includes a plurality of elongated channel structures (e.g., fins or nanoribbons) and one or more metal gate lines crossing over the fins/nanoribbons. A buried power rail (BPR) is formed between a pair of adjacent fins/nanoribbons. Once a BPR has been formed, an opening is formed above the BPR. The opening has an elongated shape that extends horizontally along the length of the BPR and extends vertically from the top of the BPR to the top of the IC structure, cutting through the metal gate lines. Portions of the opening between cut portions of metal gate lines may be filled with a dielectric material, thus forming metal gate cuts. A portion of the opening that is not between cut portions of a metal gate line is filled with an electrically conductive material and coupled to a source/drain contact of a transistor, thus forming a conductive via.

Integrated circuit structures with gate cuts above buried power rails

Techniques to form self-aligned lateral contacts. In an example, a first trench contact contacts a source or drain region of a transistor. A second trench contact includes non-contiguous first and second portions, each portion having a top surface that is co-planar with a top surface of the first trench contact as well as a top surface of the gate structure. A sidewall of the second trench contact is self-aligned to, and interfaces with, a sidewall of the first trench contact. A via extends from the first portion of the second trench contact to an underlying power rail. In some cases, the second portion of the second trench contact extends over a source or drain region of another transistor, without contacting that source or drain region. The fly-over portion of the second trench contact has a maximum height that is shorter than a maximum height of the first trench contact.

Self-aligned lateral contacts

Disclosed herein are transistor arrangements with trench contacts that have two parts—a first trench contact and a second trench contact—stacked over one another. Such transistor arrangements may be fabricated by forming a first trench contact over a source or drain contact of a transistor, recessing the first trench contact, forming the second trench contact over the first trench contact, and, finally, forming a gate contact that is electrically isolated from, while being self-aligned to, the second trench contact. Such a fabrication process may provide improvements in terms of increased edge placement error margin, cost-efficiency, and device performance, compared to conventional approaches to forming trench and gate contacts. The conductive material of the first trench contact may also be deposited over the gate electrodes of transistors, forming a gate strap, to advantageously reduce gate resistance.

Transistor arrangements with stacked trench contacts and gate straps

Discussed herein is device contact sizing in integrated circuit (IC) structures. In some embodiments, an IC structure may include: a first source/drain (S/D) contact in contact with a first S/D region, and a second S/D contact in contact with a second S/D region, wherein the first S/D region and the second S/D region have a same length, and the first S/D contact and the second S/D contact have different lengths.

Device contact sizing in integrated circuit structures

Disclosed herein are methods for fabricating IC structures that include stacked vias providing electrical connectivity between metal lines of different layers of a metallization stack, as well as resulting IC structures. An example IC structure includes a first and a second metallization layers, including, respectively, a bottom metal line and a top metal line. The IC structure further includes a via that has a bottom via portion and a top via portion, where the top via portion is stacked over the bottom via portion (hence, the via may be referred to as a 'stacked via'). The bottom via portion is coupled and self-aligned to the bottom electrically conductive line, while the top via portion is coupled and self-aligned to the top electrically conductive line. The bottom via portion is formed using selective growth, e.g., assisted by a self-assembled monolayer (SAM) material.

Stacked vias with bottom portions formed using selective growth

Contact over active gate (COAG) structures with a tapered gate or trench contact are described. In an example, an integrated circuit structure includes a plurality of gate structures above a substrate, wherein individual ones of the plurality gate of structures have thereon a conductive cap between sidewall spacers. A plurality of conductive trench contact structures is alternating with the plurality of gate structures, wherein individual ones of the plurality of conductive trench contact structures have thereon a conductive cap between sidewall spacers. A conductive structure is in direct contact with the conductive cap and sidewall spacers on one of the plurality of gate structures or with the conductive cap and sidewall spacers on one of the plurality of conductive trench contact structures.

Contact over active gate structures with tapered gate or trench contact for advanced integrated circuit structure fabrication

Methods for fabricating a transistor arrangement of an IC structure by using a placeholder for backside contact formation, as well as related semiconductor devices, are disclosed. An example method includes forming, in a support structure (e.g., a substrate, a chip, or a wafer), a dielectric placeholder for a backside contact as the first step in the method. A nanosheet superlattice is then grown laterally over the dielectric placeholder, and a stack of nanoribbons is formed based on the superlattice. The nanoribbons are processed to form S/D regions and gate stacks for future transistors. The dielectric placeholder remains in place until the support structure is transferred to a carrier wafer, at which point the dielectric placeholder is replaced with the backside contact. Use of a placeholder for backside contact formation allows alignment of contact from the backside to appropriate device ports of a transistor arrangement.

Use of a placeholder for backside contact formation for transistor arrangements

Transistor arrangements fabricated by forming a metal gate cut as an opening that is non-selective to the gate sidewalls are disclosed. The etch process may be used to provide a power rail if the opening is at least partially filled with an electrically conductive material. Once an electrically conductive material has been deposited within the opening to form a power rail, recessing such a material in portions of the power rail that face gate stacks of various transistors may provide further improvements in terms of reduced parasitic capacitance. A mask for a trench contact to be used to electrically couple the power rail to a S/D region of a transistor may be used as a mask when the electrically conductive material of the power rail is recessed to realize a via that is self-aligned to the trench contact.

Buried power rails with self-aligned vias to trench contacts

Discussed herein are device contacts in integrated circuit (IC) structures. In some embodiments, an IC structure may include: a first source/drain (S/D) contact; a gate contact, wherein the gate contact is in contact with a gate and with the first S/D contact; and a second S/D contact, wherein a height of the second S/D contact is less than a height of the first S/D contact.

Growing community of inventors

Yamhill, OR, United States of America

Andy Chih-Hung Wei