Direct Channel Implantation of B and BF ₂ Ions for Functional Control of Oxygen Vacancies in Oxide Semiconductor Thin Film Transistors

The practical utilization of oxide semiconductor thin‐film transistors (TFTs) is constrained by the trade‐off between electrical performance and stability. Here, we present directly channel‐implanted amorphous indium–gallium–zinc oxide (IGZO) TFTs using B and BF 2 ions as an oxygen vacancies (V O ) engineering technique to improve both electrical properties and stability. B implantation formed V O and oxygen interstitials (O i ) simultaneously, inducing defect formation and increasing the overall carrier concentration of the channel. In contrast, F ions from BF 2 implantation passivate V O and suppress excessive defect formation within the channel. As a result, the field‐effect mobility (µ FE ) of IGZO TFT was enhanced from 12.1 ± 0.6 to 38.6 ± 2.2 cm 2 /V·s after B implantation and to 38.1 ± 1.0 cm 2 /V·s after BF 2 implantation, at 60 keV. Under positive/negative bias temperature and illumination stress (PBTS/NBIS) conditions, the threshold‐voltage shift (|ΔV TH |) of 40 keV B ion‐implanted IGZO TFTs increased from 2.46 to 4.44 V and from 3.12 to 4.39 V, respectively. Conversely, the |ΔV TH | of 40 keV BF 2 ion‐implanted IGZO TFTs decreased from 2.46 to 1.74 V and from 3.12 to 1.04 V under PBTS/NBIS conditions, respectively. Consequently, direct channel ion implantation demonstrates strong potential for simultaneously enhancing electrical performance and stability of oxide semiconductor TFTs.