Highly Homogeneous 2D/3D Heterojunction Diodes by Pulsed Laser Deposition of MoS<sub>2</sub> on Ion Implantation Doped 4H‐SiC
Filippo Giannazzo, Salvatore Ethan Panasci, Emanuela Schilirò, Patrick Fiorenza, Giuseppe Greco, Fabrizio Roccaforte, M. Cannas, S. Agnello, Antal A. Koós, B. Pécz, M. Španková, Š. Chromík
Abstract
Abstract In this paper, 2D/3D heterojunction diodes have been fabricated by pulsed laser deposition (PLD) of MoS 2 on 4H‐SiC(0001) surfaces with different doping levels, i.e., n − epitaxial doping (≈10 16 cm −3 ) and n + ion implantation doping (>10 19 cm −3 ). After assessing the excellent thickness uniformity (≈3L‐MoS 2 ) and conformal coverage of the PLD‐grown films by Raman mapping and transmission electron microscopy, the current injection across the heterojunctions is investigated by temperature‐dependent current–voltage characterization of the diodes and by nanoscale current mapping with conductive atomic force microscopy. A wide tunability of the transport properties is shown by the SiC surface doping, with highly rectifying behavior for the MoS 2 /n − SiC junction and a strongly enhanced current injection for MoS 2 /n + SiC one. Thermionic emission is found the dominant mechanism ruling forward current in MoS 2 /n − SiC diodes, with an effective barrier Φ B = (1.04 ± 0.09) eV. Instead, the significantly lower effective barrier Φ B = (0.31 ± 0.01) eV and a temperature‐dependent ideality factor for MoS 2 /n + SiC junctions is explained by thermionic‐field‐emission through the thin depletion region of n + doped SiC. The scalability of PLD MoS 2 deposition and the electronic transport tunability by implantation doping of SiC represents key steps for industrial development of MoS 2 /SiC devices.