Taiwan Semiconductor Manufacturing Comp. Ltd.

Shu-Cheng Chin

Chih-Chien Chi

Hung-Wen Su

Chi-Feng Lin

Yao-Min Liu

Ming-Yuan Gao

Hsin-Ying Peng

Yen-Chun Lin

Ming-Hsing Tsai

Pei-Hsuan Lee

Chih-Hsiang Chang

Chia-Pang Kuo

Cheng-Hui Weng

Chih-Yi Chang

Chen-Yi Niu

Chun-Chieh Lin

Ya-Lien Lee

Kai-Shiang Kuo

Kuan-Chia Chen

Huei-Wen Hsieh

Ming-Chou Chiang

Wei Hsiang Chan

Jau-Jiun Huang

A blocking material is selectively deposited on a bottom surface of a back end of line (BEOL) conductive structure such that a barrier layer is selectively deposited on sidewalls of the BEOL conductive structure but not the bottom surface. The blocking material is etched such that copper from a conductive structure underneath is exposed, and a ruthenium layer is deposited on the barrier layer but less ruthenium is deposited on the exposed copper. Accordingly, the barrier layer prevents diffusion of metal ions from the BEOL conductive structure and is substantially absent from the bottom surface as compared to the sidewalls in order to reduce contact resistance. Additionally, the ruthenium layer reduces surface roughness within the BEOL conductive structure and is thinner at the bottom surface as compared to the sidewalls in order to reduce contact resistance.

Conductive structures with bottom-less barriers and liners

Barrier-free interconnects and methods of fabrication thereof are disclosed herein. An exemplary interconnect structure has a conductive line disposed over a conductive via. The conductive line has a first conductive plug disposed in a first dielectric layer, and the first conductive plug includes an electrically conductive non-metal material, such as graphite. The conductive via includes a second conductive plug disposed in a second dielectric layer, and the second conductive plug includes a metal material, such as tungsten, ruthenium, molybdenum, or combinations thereof. The first conductive plug physically contacts the second conductive plug and the second dielectric layer. The second conductive plug physically contacts the second dielectric layer. Spacers (which are insulators) may be disposed between sidewalls of the first conductive plug and the first dielectric layer. The spacers may further be disposed between the first dielectric layer and the second dielectric layer.

Graphite-based interconnects and methods of fabrication thereof

Various back end of line (BEOL) layer formation techniques described herein enable reduced contact resistance, reduced surface roughness, and/or increased semiconductor device performance for BEOL layers such as interconnects and/or metallization layers.

Semiconductor devices and methods of formation

A method includes forming a first conductive feature, depositing a graphite layer over the first conductive feature, patterning the graphite layer to form a graphite conductive feature, depositing a dielectric spacer layer on the graphite layer, depositing a first dielectric layer over the dielectric spacer layer, planarizing the first dielectric layer, forming a second dielectric layer over the first dielectric layer, and forming a second conductive feature in the second dielectric layer. The second conductive feature is over and electrically connected to the graphite conductive feature.

Interconnect structure including graphite and method forming same

A method includes forming a first conductive feature in a first dielectric layer. A second dielectric layer is formed over the first conductive feature and the first dielectric layer. An opening is formed in the second dielectric layer. The opening exposes a top surface of the first conductive feature. The top surface of the first conductive feature includes a first metallic material and a second metallic material different from the first metallic material. A native oxide layer is removed from the top surface of the first conductive feature. A surfactant soaking process is performed on the top surface of the first conductive feature. The surfactant soaking process forms a surfactant layer over the top surface of the first conductive feature. A first barrier layer is deposited on a sidewall of the opening. The surfactant layer remains exposed at the end of depositing the first barrier layer.

Interconnect structure of semiconductor device

A barrier layer is selectively formed on a bottom surface of a recess (e.g., in which a back end of line (BEOL) conductive structure will be formed) using a combination of flash physical vapor deposition with atomic layer deposition. Additionally, a ruthenium liner is selectively deposited on sidewalls of the BEOL conductive structure using a blocking material. Accordingly, the barrier layer prevents diffusion of metal ions from the BEOL conductive structure and is thinner at the bottom surface as compared to the sidewalls in order to reduce contact resistance. Additionally, the ruthenium liner improves copper flow into the BEOL conductive structure and is thinner at the bottom surface in order to further reduce contact resistance.

Conductive structures with barriers and liners of varying thicknesses

A graphene liner deposited between at least one liner material (e.g., barrier layer, ruthenium liner, and/or cobalt liner) and a copper conductive structure reduces surface scattering at an interface between the at least one liner material and the copper conductive structure. Additionally, or alternatively, the carbon-based liner reduces contact resistance at an interface between the at least one liner material and the copper conductive structure. A carbon-based cap may additionally or alternatively be deposited on a metal cap, over the copper conductive structure, to reduce surface scattering at an interface between the metal cap and an additional copper conductive structure deposited over the metal cap.

Graphene liners and caps for semiconductor structures

A semiconductor device includes an insulating layer, wherein the insulating layer has a via opening and a conductive line opening. The semiconductor device further includes a via in the via opening. The semiconductor device further includes a conductive line in the conductive line opening. The conductive line includes a first liner layer, wherein a first thickness of the first liner layer over the via is less than a second thickness of the first liner layer over the insulating layer, and a conductive fill, wherein the first liner layer surrounds the conductive fill.

Semiconductor device having a contact structure

A method of manufacturing an interconnect structure includes forming an opening through a dielectric layer. The opening exposes a top surface of a first conductive feature. The method further includes forming a barrier layer on sidewalls of the opening, passivating the exposed top surface of the first conductive feature with a treatment process, forming a liner layer over the barrier layer, and filling the opening with a conductive material. The liner layer may include ruthenium.

Method of forming interconnect structure having a barrier layer

In some implementations, one or more semiconductor processing tools may form a via within a substrate of a semiconductor device. The one or more semiconductor processing tools may deposit a ruthenium-based liner within the via. The one or more semiconductor processing tools may deposit, after depositing the ruthenium-based liner, a copper plug within the via.

Ruthenium-based liner for a copper interconnect

A method of making a semiconductor device includes etching an insulating layer to form a first opening and a second opening. The method further includes depositing a conductive material in the first opening. The method further includes performing a surface modification process on the conductive material. The method further includes depositing, after the surface modification process, a first liner layer in the second opening, wherein the first liner layer extends over the conductive material and the insulating layer. The method further includes depositing a conductive fill over the first liner layer, wherein the conductive fill includes a different material from the conductive material.

Method of making a contact structure

Selective ruthenium and selective ruthenium oxide may be used in single damascene processes and/or dual damascene processes to form BEOL metallization layers and vias of an electronic device. A selective ruthenium liner may be formed to achieve a low contact resistance and a low sheet resistance for the BEOL metallization layers and vias, to promote adhesion between the various layers and materials in the BEOL metallization layers and vias, and/or to reduce or eliminate defects (such as voids and discontinuities) in the BEOL metallization layers and vias.

Ruthenium oxide film and ruthenium liner for low-resistance copper interconnects in a device

Interconnect structure and method of forming thereof

A semiconductor device includes an insulating layer, wherein the insulating layer has a via opening and a conductive line opening. The semiconductor device further includes a via in the via opening, wherein the via includes a first conductive material. The semiconductor device further includes a conductive line in the conductive line opening. The conductive line includes a first liner layer, wherein a first thickness of the first liner layer over the via is less than a second thickness of the first liner layer over the insulating layer, and a conductive fill comprising a second conductive material different from the first conductive material.

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Hsinchu, Taiwan

Shu-Cheng Chin