MoS2 Field-Effect Transistors With Graphene/Metal Heterocontacts

Yuchen Du, Purdue University, Birck Nanotechnology Center
Lingming Yang, Purdue University, Birck Nanotechnology Center
Jingyun Zhang, Purdue University, Birck Nanotechnology Center
Han Liu, Purdue University, Birck Nanotechnology Center
Kausik Majumdar, SEMATECH
Paul D. Kirsch, SEMATECH
Peide D. Ye, Purdue University, Birck Nanotechnology Center

Abstract

For the first time, n-type few-layer MoS2 field-effect transistors (FETs) with graphene/Ti as the heterocontacts have been fabricated, showing more than 160-mA/mm drain current at 1-mu m gate length with an ON-OFF current ratio of 10(7). The enhanced electrical characteristic is confirmed in a nearly 2.1 times improvement in ON-resistance and a 3.3 times improvement in contact resistance with heterocontacts compared with the MoS2 FETs without graphene contact layer. Temperature-dependent study on MoS2/graphene heterocontacts has been also performed, still unveiling its Schottky contact nature. Transfer length method and a devised I-V method have been introduced to study the contact resistance and Schottky barrier height in MoS2/graphene/metal heterocontacts structure.

Discipline(s)

Nanoscience and Nanotechnology