| AVS 66th International Symposium & Exhibition | |
| 2D Materials | Tuesday Sessions |
| Session 2D-TuP |
| Session: | 2D Poster Session |
| Presenter: | Chien-Bao Lin, TIRI/NARL, Taiwan, Republic of China |
| Authors: | C.-A. Jong, TSRI/NARL, Taiwan, Republic of China Y. Yang, NTNU, Taiwan, Republic of China M.-H. Le, NTHU, Taiwan, Republic of China P.-S. Chen, MUST, Taiwan, Republic of China C.-B. Lin, TIRI/NARL, Taiwan, Republic of China P.-K. Chiu, TIRI/NARL, Taiwan, Republic of China C.-N. Hsiao, TIRI/NARL, Taiwan, Republic of China |
| Correspondent: | Click to Email |
Lots of TMDs materials with fantastic properties have been widely discovered for electrical and optical device application. In order to replace current Si-based device several challenges should be overcame, including the 2D synthesis and patterning technique; heterojunction control between TMDs to TMDs, TMDs to dielectric film and TMDs to metallic film, doping technique and so on. Among them, MoS2 and WSe2 have shown their excellent electron and hole mobility in NFET and PFET evaluation. For electronic and photonic applications, a material existing air-stable, high carrier mobility, high on/off ratio, as well as a tunable band gap is far more desirable. Recent theoretical and experimental data show some noble chalcogenides can also form layered structures with S or Se atoms, like PdS2 and PdSe2[1-3]. Each Pd atom can bond to four S or Se atoms, respectively. Puckered PdSe2 exhibit a widely tunable band gap that varies from metallic (bulk) to ∼1.3 eV (monolayer) and the field-effect transistors made from PdSe2 reveal high electron field-effect mobility of ∼158 cm2/Vs are presented [4]. Recently, Mahdi et al., [5] proposed a unique alternative to reduce contact resistance through the single material junction device scheme, that is, using a single material (PdS2) in channel and S/D region. Monolayer PdS2 was found to be semiconducting with a bandgap of 1.1 eV and became semi-metallic as bilayer. PdS2 was also reported with a high electron mobility than MoS2. However, not too much experimental works has been published yet in PdS2 synthesis. To realize the reported device integration, the thickness control and sulfurization process are important. In our previous works [6-7], a possible approach in untra-thin and uniform 2D layer film synthesis was demonstrated combined with proposed ALE and sulfurization process.
In this study, the PdS2 film synthesis and single material junction device fabrication will be performed. Pd film was sputtered onto SiO2/Si substrate for sulfurization. The PdS2 film was obtained after sulfurization and the structure is verified [8]. The XRD, XPS and Raman spectrum are measured for microstructure evaluation. A lift -off process in channel and source and drain patterning was achieved. With the help of anisotropic etch in Pd film thin down, the desired thickness and wafer scale flatness was controlled. The etched thickness and surface roughness are monitored by AFM. Followed by the etch process, the etched samples were sulfurized for PdS2 formation. After the sulfurization process the homo-junction device using a single material was fabricated and the electrical properties was characterization.