Surface treatment of TaN for sub-2 nm, smooth, and conducting atomic layer deposition Ru films-Reference-Cited by-同舟云学术

Surface treatment of TaN for sub-2 nm, smooth, and conducting atomic layer deposition Ru films

Published:2024-04-03 Issue:3 Volume:42 Page:
ISSN:0734-2101
Container-title:Journal of Vacuum Science & Technology A
language:en
Short-container-title:

Author:

Feit Corbin¹,Kumar Udit¹^ORCID,Islam Md. Rafiqul²,Tomar Luis¹,Berriel S. Novia¹^ORCID,Gaskins John T.³^ORCID,Hopkins Patrick E.²⁴⁵,Seal Sudipta¹⁶^ORCID,Banerjee Parag¹⁶⁷⁸^ORCID

Affiliation:

1. Department of Materials Science and Engineering, University of Central Florida 1 , Orlando, Florida 32816

2. Department of Mechanical and Aerospace Engineering, University of Virginia 2 , Charlottesville, Virginia 22904

3. Laser Thermal 3 , Charlottesville, Virginia 22902

4. Department of Materials Science and Engineering, University of Virginia 4 , Charlottesville, Virginia 22904

5. Department of Physics, University of Virginia 5 , Charlottesville, Virginia 22904

6. Nano Science and Technology Center, University of Central Florida 6 , Orlando, Florida 32816

7. Florida Solar Energy Center, University of Central Florida 7 , Orlando, Florida 32816

8. REACT Faculty Cluster, University of Central Florida 8 , Orlando, Florida 32816

Abstract

Atomic layer deposition (ALD) of ruthenium (Ru) is being investigated for next generation interconnects and conducting liners for copper metallization. However, integration of ALD Ru with diffusion barrier refractory metal nitrides, such as tantalum nitride (TaN), continues to be a challenge due to its slow nucleation rates. Here, we demonstrate that an ultraviolet-ozone (UV-O3) pretreatment of TaN leads to an oxidized surface that favorably alters the deposition characteristics of ALD Ru from islandlike to layer-by-layer growth. The film morphology and properties are evaluated via spectroscopic ellipsometry, atomic force microscopy, electrical sheet resistance measurements, and thermoreflectance. We report a 1.83 nm continuous Ru film with a roughness of 0.19 nm and a sheet resistance of 10.8 KΩ/□. The interface chemistry between TaN and Ru is studied by x-ray photoelectron spectroscopy. It is shown that UV-O3 pretreatment, while oxidizing TaN, enhances Ru film nucleation and limits further oxidation of the underlying TaN during ALD. An oxygen “gettering” mechanism by TaN is proposed to explain reduced oxygen content in the Ru film and higher electrical conductivity compared to Ru deposited on native-TaN. This work provides a simple and effective approach using UV-O3 pretreatment for obtaining sub-2 nm, smooth, and conducting Ru films on TaN surfaces.

Funder

National Science Foundation

Semiconductor Research Corporation

Publisher

American Vacuum Society

Link

https://pubs.aip.org/avs/jva/article-pdf/doi/10.1116/6.0003440/19866234/032407_1_6.0003440.pdf

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