title: Strain Gated Bilayer Molybdenum Disulfide Field Effect Transistor with Edge Contacts.
abstract: Silicon nitride stress capping layer is an industry proven technique for increasing electron mobility and drive currents in n-channel silicon MOSFETs. Herein, the strain induced by silicon nitride is firstly characterized through the changes in photoluminescence and Raman spectra of a bare bilayer MoS2(Molybdenum disulfide). To make an analogy of the strain-gated silicon MOSFET, strain is exerted to a bilayer MoS2field effect transistor (FET) through deposition of a silicon nitride stress liner that warps both the gate and the source-drain area. Helium plasma etched MoS2layers for edge contacts. Current on/off ratio and other performance metrics are measured and compared as the FETs evolve from back-gated, to top-gated and finally, to strain-gated configurations. While the indirect band gap of bilayer MoS2at 0% strain is 1.25 eV, the band gap decreases as the tensile strain increases on an average of ~100 meV per 1% tensile strain, and the decrease in band gap is mainly due to lowering the conduction band at K point. Comparing top- and strain-gated structures, we find a 58% increase in electron mobility and 46% increase in on-current magnitude, signalling a benign effect of tensile strain on the carrier transport properties of MoS2.
authors.affiliation: Materials Science and Engineering Program, University of California, Riverside, CA 92521 USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Department of Electrical and Comp. Engineering, University of California, Riverside, CA 92521 USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Su
authors.affiliation: Center for Nanoscale Science &Engineering, University of California, Riverside, CA 92521 USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Yan
authors.affiliation: Department of Electrical and Comp. Engineering, University of California, Riverside, CA 92521 USA.
authors.forename: Mihrimah
authors.initials: M
authors.lastname: Ozkan
authors.affiliation: Department of Electrical and Comp. Engineering, University of California, Riverside, CA 92521 USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Lake
authors.affiliation: Materials Science and Engineering Program, University of California, Riverside, CA 92521 USA.|Department of Mechanical Engineering, University of California, Riverside, CA 92521 USA.
authors.forename: Cengiz S
authors.initials: CS
authors.lastname: Ozkan