Using Ar Ion beam exposure to improve contact resistance in MoS2 FETs
© 2016 IEEE. Contact resistance is a dominant factor in the performance of field-effect transistors (FETs) from two-dimensional MoS 2 . Several techniques have been shown to improve carrier transport at the metal-MoS 2 interface, thus lowering the contact resistance. These approaches include the use of molecular doping , different contact materials [2-5] , phase transformation of MoS 2 , and adding an interfacial oxide at the contacts [7, 8] . The challenges for the most effective of these techniques are that they generally require additional processing, sometimes involving very high temperatures, or the addition of materials at the metal-MoS 2 interface that may lower contact resistance but still yield relatively poor FET performance. In graphene, it has been demonstrated that intentionally damaging the crystal lattice in the contact region using O 2 plasma can substantially reduce the contact resistance [9-11]. In this work, we examine a related contact engineering approach for MoS 2 FETs by using an in situ, broad-beam ion source to modify the MoS 2 lattice immediately prior to contact metal deposition. The result is a substantial improvement in key performance metrics, including contact resistance and on-current.
Cheng, Z; Cardenas, JA; McGuire, F; Franklin, AD
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International Standard Book Number 13 (ISBN-13)
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