High On-State Current in Chemical Vapor Deposited Monolayer MoS2nFETs with Sn Ohmic Contacts
Journal
IEEE Electron Device Letters
Journal Volume
42
Journal Issue
2
Pages
272-275
Date Issued
2021
Author(s)
Abstract
Proving the device performance and process feasibility is imperative for the realization of two-dimensional (2D) semiconductor electronics. In this work, we have successfully adopted Tin (Sn) as the Ohmic contact metal to monolayer molybdenum disulfide (MoS2) grown by chemical vapor deposition (CVD) and demonstrated superior short channel n-type field effect transistor (nFET) performance reaching an ON-current of 480~μ A/μ m and keeping the OFF-current below 0.1 nA/ μ m at V_DS = 1 V. These efforts are close to the low power specification of Si transistors in the metrics of International Roadmap for Devices and Systems (IRDS). The performance improvement could be attributed to the re-melting behavior of Sn metal. We suggest that the Sn deposited at lower temperatures could reduce the formation of interfacial defects caused by heat, and high-melting-point capping metal also could assist the re-melting phenomenon of underlying Sn contact layer. These process modifications are helpful to form smooth Sn coverage on MoS2, thereby reducing the contact resistance to 0.84 kOmega cdot μ m. This work provides a practical pathway to form low-resistance metal contact on 2D semiconductors for performance improvement. ? 1980-2012 IEEE.
Subjects
Electric contactors; Field effect transistors; Layered semiconductors; Molybdenum compounds; Monolayers; Ohmic contacts; Sulfur compounds; Tin; Chemical vapor deposited; Chemical vapor depositions (CVD); Devices and systems; Lower temperatures; Molybdenum disulfide; Process modifications; Semiconductor electronics; Two Dimensional (2 D); Chemical vapor deposition
Type
journal article