CNR ExploRA

Articolo in rivista, 2023, ENG, 10.1016/j.mssp.2023.107616

Laser induced crystallization of sputtered MoS2 thin films

Alessandro Tonon, Enrico Di Russo, Francesco Sgarbossa, Luca Bacci, Nicola Argiolas, Carlo Scian, Yurii P Ivanov, Giorgio Divitini, Brendan Sheehan, Davide De Salvador, Andrea Gasparotto, Vittorio Morandi, Ray Duffy, Enrico Napolitani

a Università Degli Studi di Padova, Dipartimento di Fisica e Astronomia, via Marzolo 8, 35131, Padova, Italy b Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, viale Dell'Università 2, 35020, Legnaro, (PD), Italy c CNR-IMM, Via Gobetti 101, Bologna, 40129, Italy d Electron Spectroscopy and Nanoscopy, Istituto Italiano di Tecnologia, Via Morego 30, Genova, 16163, Italy e Tyndall National Institute, University College Cork, Lee Maltings, Cork, T12 R5CP, Ireland f CNR-IMM, Via S. Sofia 64, 95123, Catania, Italy

The integration of transition metal dichalcogenides (TMDs) thin films into Si CMOS-based devices requires the development of new bottom-up material growth approaches producing high crystallinity films without affecting the SiO2/Si substrate. For this purpose, sputtering is a suitable deposition method due to its simplicity, jointly with high reliability and large area deposition capabilities. However, sputtered layers are amorphous and require a post-deposition thermal treatment to obtain a highly crystalline film. Nanosecond pulsed laser annealing (PLA) has recently emerged as promising route to achieve large-scale crystalline TMDs films without significantly heating or affecting the underlying substrate. The aim of this work is to explore the possibility to produce crystalline 2H-MoS2 on large areas directly on a SiO2-on-Si substrate. The film structure, composition and morphology were monitored as a function of the laser pulse energy density by Raman spectroscopy, X-rays diffraction, Rutherford backscattered spectroscopy (RBS), scanning transmission electron microscopy (STEM) and atomic force microscopy (AFM). The electrical properties of the film with optimized crystallinity were finally investigated through deposition of Cr/Au contacts using shadow masks. This approach can be scaled to other TMDs materials and substrates, also paving the way for the fabrication of heterostructures and electrical devices on the top of a single substrate.

Materials science in semiconductor processing