| AVS 65th International Symposium & Exhibition | |
| Plasma Science and Technology Division | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Division Poster Session |
| Presenter: | Gary Kushto, U.S. Naval Research Laboratory |
| Authors: | S.G. Walton, U.S. Naval Research Laboratory D.R. Boris, U.S. Naval Research Laboratory A.C. Kozen, American Society for Engineering Education G. Kushto, U.S. Naval Research Laboratory M.J. Johnson, National Research Council R.H. Rai, University of Dayton N.R. Glavin, Air Force Research Laboratory C. Muratore, University of Dayton |
| Correspondent: | Click to Email |
The ability to grow high-quality, continuous 2D transition metal dichalcogenides (TMDs) on polymer substrates is a prerequisite for commercial flexible devices based on these materials. Molybdenum disulfide (MoS2) is a promising 2D semiconductor due to its relatively high charge mobility and a direct band gap of 1.8 eV coupled with optical transparency and high mechanical flexibility. Recently, magnetron sputtering from pure TMD targets, such as MoS2 and WS2, was used for growth of amorphous precursor films at room temperature on polydimethylsiloxane substrates. Ex situ laser annealing after film growth was then used to drive an amorphous-to-crystalline phase change. While successful, the phase change was limited to the area defined by the beam diameter. Rapid, large scale, in situ methods would be an attractive alternative to meet the demands for commercial scale manufacturing.
In this work, we discuss the development of a plasma-based approach to driving the crystallization of few-layer, amorphous MoS2 on polymers. The amorphous MoS2 was deposited, via magnetron sputtering of MoS2 targets, on polydimethyl siloxane (PDMS) substrates. The films were then exposed to electron beam generated plasmas produced in pure and dilute argon backgrounds to drive crystallization. The use of electron beam generated plasmas are attractive since they are both scalable to large areas and deliver a large ion fluence with kinetic energies as low as a few eV. The ion energies can be raised using DC or RF biasing, allowing the system to be tuned to deliver the energy required to drive the phase transition but limit etching and damage to monolayer films. The treated films are characterized using Raman, XPS, and Kelvin probes and those results will be discussed in terms of operating conditions such as treatment times, operating gas mixture, and ion energy. This work was partially supported by the Naval Research Laboratory base program.