Scalable transfer-free fabrication of PtSe₂ FETs

Two-dimensional (2D) semiconductors have attracted significant attention for next-generation electronic applications. Among them, platinum diselenide (PtSe2) stands out due to its high predicted carrier mobility and its unique thickness-dependent electronic properties, transitioning from semiconducting behavior in ultrathin layers to semimetallic characteristics in thicker films. In this work, we report a transfer-free, lithography-compatible fabrication approach for PtSe2 field-effect transistors directly on Si/SiO2 substrates. The method exploits the intrinsic thickness-dependent properties of PtSe2 to realize homostructure devices, where thin regions act as the semiconducting channel and thicker regions serve as conductive contacts. Device structures are defined by conventional photolithography and lift-off of Pt, followed by a single selenization step that converts the patterned metal into PtSe2. Importantly, the selenization process constitutes the final fabrication step, preventing further processing-induced degradation of the ultrathin channel. The proposed strategy is compatible with standard microfabrication processes and enables deterministic patterning of device architectures. This transfer-free approach provides a promising route toward scalable integration of PtSe2-based electronics and advances the practical implementation of 2D semiconductor technologies.