Invited Paper GR+EM+MS+NS+SP-FrM5
MoS₂ MOSFETs: Dielectrics, Metal Contacts and Scaling

Friday, November 1, 2013, 9:40 am, Room 101 A

The discovery of graphene has unveiled another material family with layered structures, which includes boron nitride, topological insulators such as Bi₂Te₃ and Bi₂Se₃, and transition metal dichalcogenides like MoS₂, WS₂, and NbSe₂. Though graphene, a fascinating two-dimensional (2D) crystal, has shown a superior carrier mobility of up to 200,000 cm²/V·s, its zero bandgap property limits its application to logic devices as graphene transistors cannot have high on/off ratios. As opposed to the semi-metal graphene, transition metal dichalcogenides (such as MoS₂), as another type of layered structure material, have shown great potential in device applications due to their satisfied bandgaps, thermal stability, carrier mobility, and compatibility to silicon CMOS process. In order to realize high performance MoS₂ MOSFETs [1], three major issues must be solved: 1) how to deposit a high-quality dielectric on 2D crystal, 2) the fabrication of low-resistivity metal-semiconductor junction to be used as device contacts, and 3) the elimination of short channel effects. [2,3] In this talk, I will review the recent progress in this field about these three device aspects and discuss the fundamental physics, chemistry, and posible solutions on these challenges.

The work is in close collaborations with H. Liu, A.T. Neal, and Y.C. Du. The authors appreciate SRC GRC for the support.

[1] Radisavljevic, B.; Radenovic, A.; Brivio, J.; Giacometti, V.; Kis, A. Single-Layer MoS₂ Transistors, Nat. Nanotechnol.2011, 6, 147 – 150.

[2] Liu, H.; Neal, A.T.; Ye, P.D. Channel Length Scaling of MoS₂ MOSFETs, ACS Nano 2012, 6, 8563-8569.

[3] Liu, H.; Ye, P.D. MoS2 Dual-Gate MOSFET with Atomic-Layer-Deposited Al₂O₃ as Top-Gate Dielectric, IEEE Electron Device Lett. 2012, 33, 546-548.