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Two-dimensional (2D) semiconductors, especially transition metal dichalcogenides (TMDCs), have been proven to be excellent channel materials for the next-generation integrated circuit (IC). However, the contact problem between 2D TMDCs and metal electrodes has always been one of the main factors restricting their development. In this review, we summarized recent work on 2D TMDCs contact from the perspective of compatible integration with silicon processes and practical application requirements, including the contact performance evaluation indicators, special challenges encountered in 2D TMDCs, and recent optimization methods. Specifically, we sorted out and highlighted the performance indicators of 2D TMDCs contacts, including contact resistance (RC), contact scaling, contact stability, and contact electrical/thermal conductivity. Special challenges of 2D TMDCs and metal contact, such as severe Fermi level pinning, large RC, and difficult doping, are systematically discussed. Furthermore, typical methods for optimizing 2D TMDCs RC, edge contact strategies for scaling contact lengths, and solutions for improving contact stability are reviewed. Based on the current research and problems, the development direction of 2D TMDCs contacts that meet the silicon-based compatible process and application performance requirements is proposed.


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Silicon-processes-compatible contact engineering for two-dimensional materials integrated circuits

Show Author's information Li Gao1,2Zhangyi Chen1Chao Chen1Xiankun Zhang1,3( )Zheng Zhang1,3( )Yue Zhang1,2,3( )
Academy for Advanced Interdisciplinary Science and Technology, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China
School of Materials Science and Engineering, Peking University, Beijing 100871, China
Key Laboratory of Advanced Materials and Devices for Post-Moore Chips, Ministry of Education, University of Science and Technology Beijing, Beijing 100083, China

Abstract

Two-dimensional (2D) semiconductors, especially transition metal dichalcogenides (TMDCs), have been proven to be excellent channel materials for the next-generation integrated circuit (IC). However, the contact problem between 2D TMDCs and metal electrodes has always been one of the main factors restricting their development. In this review, we summarized recent work on 2D TMDCs contact from the perspective of compatible integration with silicon processes and practical application requirements, including the contact performance evaluation indicators, special challenges encountered in 2D TMDCs, and recent optimization methods. Specifically, we sorted out and highlighted the performance indicators of 2D TMDCs contacts, including contact resistance (RC), contact scaling, contact stability, and contact electrical/thermal conductivity. Special challenges of 2D TMDCs and metal contact, such as severe Fermi level pinning, large RC, and difficult doping, are systematically discussed. Furthermore, typical methods for optimizing 2D TMDCs RC, edge contact strategies for scaling contact lengths, and solutions for improving contact stability are reviewed. Based on the current research and problems, the development direction of 2D TMDCs contacts that meet the silicon-based compatible process and application performance requirements is proposed.

Keywords: transition metal dichalcogenides, two-dimensional (2D) semiconductors, field effect transistors, contact engineering

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Publication history
Copyright
Acknowledgements

Publication history

Received: 11 August 2023
Revised: 04 September 2023
Accepted: 04 September 2023
Published: 27 October 2023
Issue date: November 2023

Copyright

© Tsinghua University Press 2023

Acknowledgements

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Nos. 51991340, 51991342, 52225206, 92163205, 52188101, 62322402, 62204012, 52250398, 51972022, 52303362, and 62304019), the National Key Research and Development Program of China (Nos. 2022YFA1203800, 2022YFA1203803, and 2018YFA0703503), the Overseas Expertise Introduction Projects for Discipline Innovation (No. B14003), the Frontier Cross Research Project of the Department of Chinese Academy of Sciences (No. XK2023JSA001), the Beijing Nova Program (No. 20220484145), the Young Elite Scientists sponsorship program by CAST (No. 2022QNRC001), the Fundamental Research Funds for the Central Universities (No. FRF-06500207), the Interdisciplinary Research Project for Young Teachers of USTB (Fundamental Research Funds for the Central Universities, Nos. FRF-TP-22-004C2, FRF-IDRY-21-008, FRF-06500207, FRF-TP-22-004A1, and FRF-IDRY-22-016), the State Key Lab for Advanced Metals and Materials (No. 2023-Z05), and the Special support from the Postdoctoral Science Foundation (No. 8206400173).

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