Top-Down Integration of Molybdenum Disulfide Transistors with Wafer-Scale Uniformity and Layer Controllability

5 years ago

Top-Down Integration of Molybdenum Disulfide Transistors with Wafer-Scale Uniformity and Layer Controllability

Qing-Qing Sun, Tian-Bao Zhang, Hao Zhu, Lin Chen, David Wei Zhang, Jing Xu, Mao-Lin Shi

The lack of stable and efficient techniques to synthesize high-quality large-area thin films is one of the major bottlenecks for the real-world application of the 2D transition metal dichalcogenides. In this work, the growth of molybdenum disulfide (MoS2) on sapphire substrates by sulfurizing the MoO3 film deposited by atomic layer deposition (ALD) is reported. The advantages of the ALD method can be well inherited, and the synthesized MoS2 films exhibit excellent layer controllability, wafer-scale uniformity, and homogeneity. MoS2 films with desired thickness can be obtained by varying MoO3 ALD cycles. The atomic force microscope and Raman measurements demonstrate that the ALD-based MoS2 has good uniformity. Clear Raman shift as a function of the film thickness is observed. Field-effect transistor devices are fabricated through a transfer-free and top-down process. High On/Off current ratio (≈104) and medium-level electron mobilities (≈0.76 cm2 V−1 s−1 for monolayer, and 5.9 cm2 V−1 s−1 for four-layer) are obtained. The work opens up an attractive approach to realize the application of wafer-scale 2D materials in integrated circuits and systems. MoS2 films are acquired by the sulfurization of a MoO3 film predeposited by atomic layer deposition (ALD). The synthesized MoS2 retains the inherent benefits from the ALD process, including thickness controllability, reproducibility, and uniformity. Field-effect transistors are fabricated through a transfer-free and top-down process. High On/Off current ratio (≈104) and electron mobility (up to 5.9 cm2 V−1 s−1) are obtained.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/smll.201603157