200-mm-wafer-scale integration of polycrystalline molybdenum disulfide transistors

Two-dimensional semiconductors are an attractive material for making thin-film transistors due to their scalability, transferability, atomic thickness and relatively high carrier mobility. There is, however, a gap in performance between single-device demonstrations, which typically use single-crystalline two-dimensional films, and devices that can be integrated on a large scale using industrial methods. Here we report the 200-mm-wafer-scale integration of polycrystalline molybdenum disulfide (MoS₂) field-effect transistors. Our processes are compatible with industry, with processing performed in a commercial 200 mm fabrication facility with a yield of over 99.9%. We find that the metal–semiconductor junction in polycrystalline MoS₂ is fundamentally different from its single-crystalline counterpart, and therefore, we redesign the process flow to nearly eliminate the Schottky barrier height at the metal–MoS₂ contact. The resulting MoS₂ field-effect transistors exhibit mobilities of 21 cm² V⁻¹ s⁻¹, contact resistances of 3.8 kΩ µm and on-current densities of 120 µA µm⁻¹, which are similar to those achieved with single-crystalline flakes.