title: Multibit data storage states formed in plasma-treated MoS₂ transistors.
abstract: New multibit memory devices are desirable for improving data storage density and computing speed. Here, we report that multilayer MoS2 transistors, when treated with plasmas, can dramatically serve as low-cost, nonvolatile, highly durable memories with binary and multibit data storage capability. We have demonstrated binary and 2-bit/transistor (or 4-level) data states suitable for year-scale data storage applications as well as 3-bit/transistor (or 8-level) data states for day-scale data storage. This multibit memory capability is hypothesized to be attributed to plasma-induced doping and ripple of the top MoS2 layers in a transistor, which could form an ambipolar charge-trapping layer interfacing the underlying MoS2 channel. This structure could enable the nonvolatile retention of charged carriers as well as the reversible modulation of polarity and amount of the trapped charge, ultimately resulting in multilevel data states in memory transistors. Our Kelvin force microscopy results strongly support this hypothesis. In addition, our research suggests that the programming speed of such memories can be improved by using nanoscale-area plasma treatment. We anticipate that this work would provide important scientific insights for leveraging the unique structural property of atomically layered two-dimensional materials in nanoelectronic applications.
authors.affiliation: Department of Mechanical Engineering, University of Michigan , 2011 W.E. Lay Automotive Laboratory, 1231 Beal Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Mikai
authors.initials: M
authors.lastname: Chen
authors.forename: Hongsuk
authors.initials: H
authors.lastname: Nam
authors.forename: Sungjin
authors.initials: S
authors.lastname: Wi
authors.forename: Greg
authors.initials: G
authors.lastname: Priessnitz
authors.forename: Ivan Manuel
authors.initials: IM
authors.lastname: Gunawan
authors.forename: Xiaogan
authors.initials: X
authors.lastname: Liang