High-performance Atomic-Layer-Deposited SnO thin film transistors fabricated by intense pulsed light annealing

In this study, SnO films were grown by atomic layer deposition using Sn(dmamp)₂ and H₂O as the Sn-precursor and reactant, respectively, at a low temperature of 120 °C. Intense pulsed light (IPL) annealing was employed to obtain high-quality polycrystalline SnO films with excellent hole transport characteristics. The amorphous SnO film could be crystallized by IPL annealing, particularly at a light pulse number between 200 and 300, and the degree of crystallinity increased with increasing IPL treatment. The Sn²⁺ oxidation state of the SnO film was almost maintained after IPL annealing, with no apparent phase transformation from SnO to SnO₂ or Sn. In addition, the IPL-annealed SnO films exhibited a smooth surface morphology with a root-mean-squared roughness of 0.22–0.50 nm. Finally, bottom-gated staggered-structured thin-film transistors (TFTs) were fabricated with 6–30 nm-thick IPL-annealed SnO channel layers. Excellent p-type SnO-based TFT performance was achieved with a field-effect hole mobility of 4.31 cm²/V·s and an on-to-off current ratio of 8.2 × 10⁴.