Substrate‐Versatile and Stress‐Free Tellurization of PtTe2 Films

Platinum ditelluride (PtTe2) is a type-II Dirac semimetal featuring tilted cones in itselectronic band structure, which leads to intriguing electronic and optical topo-logical properties. Here, a large area growth process is presented for the synthesisof PtTe2 films with nanoscale thickness by sputtering deposition of a Pt precursorlayer and subsequent tellurization at 450 °C. Although the Pt deposition step doesnot pose stringent limitation on the substrate choice, it is demonstrated that theheating rate during the tellurization step can induce a significant thermal-inducedstrain when the process is extended from silicon dielectric transparent silicasubstrates, leading to macroscopic wrinkling of the PtTe2 film. Thus, a slowertellurization process is optimized, successfully resulting in stress-free growth evenon dielectric substrates. Additionally, the same new process repeated on siliconsubstrates shows a threefold enhanced minimum grain size compared to theoriginal process. These accomplishments, combined with the scalability of thegrowth technique and the deterministic material patterning achieved by opticallithography, are crucial for a facile integration of PtTe2 in any kind of device.