Electronic Impact of High-Energy Metal Deposition on Ultrathin Oxide Semiconductors

High-energy metal deposition significantly impacts the performance and reliability of two-dimensional (2D) semiconductors and nanodevices. This study investigates the localized annealing effect in atomically thin In₂O₃ induced during high-energy metal deposition. The localized heating effect alters the electronic performance of In₂O₃ devices, especially in shorter channel devices, where heat dissipation is further constrained. This effect creates a conductivity gradient along the In₂O₃ device with higher conductivity near the metal contact, as observed by conductive atomic force microscopy (C-AFM). This gradient leads to a pronounced threshold voltage (V_th) shift as the channel length (L_ch) decreases, resembling a short-channel effect but one driven by thermal mechanisms rather than conventional mechanisms. Furthermore, metals with higher latent heats can exacerbate these effects. We also show that reversing the deposition sequence and postdeposition oxygen annealing effectively suppress V_th shifts across different L_ch. This work offers key insights into controlling thermal effects during fabrication to improve ultrathin oxide transistor performance.