Substrate‐Versatile and Stress‐Free Tellurization of PtTe2 Films

Platinum ditelluride (PtTe2) is a type-II Dirac semimetal featuring tilted cones in its electronic band structure, which leads to intriguing electronic and optical topological properties. Here, a large area growth process is presented for the synthesis of PtTe2 films with nanoscale thickness by sputtering deposition of a Pt precursor layer and subsequent tellurization at 450 °C. Although the Pt deposition step does not pose stringent limitation on the substrate choice, it is demonstrated that the heating rate during the tellurization step can induce a significant thermal-induced strain when the process is extended from silicon dielectric transparent silica substrates, leading to macroscopic wrinkling of the PtTe2 film. Thus, a slower tellurization process is optimized, successfully resulting in stress-free growth even on dielectric substrates. Additionally, the same new process repeated on silicon substrates shows a threefold enhanced minimum grain size compared to the original process. These accomplishments, combined with the scalability of the growth technique and the deterministic material patterning achieved by optical lithography, are crucial for a facile integration of PtTe2 in any kind of device.