Thermally driven electron concentration gradient in ultrathin oxide semiconductors

Yi-Yu Pan^1*, Der-Hsien Lien¹

¹Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

* Presenter:Yi-Yu Pan, email:yypan.ee10@nycu.edu.tw

Ultrathin In₂O₃ transistors offer excellent transport properties at sub-nanometer thicknesses, but suffer from threshold voltage (V_th) instability, especially in shorter channels. This instability arises due to nonuniform heat distribution during high-energy metal deposition, creating a conductivity gradient along the channel, with higher conductivity and lower V_th near metal contacts. To verify that metal deposition causes this localized annealing effect, a reversed deposition sequence was employed, confirming the thermal origin of the V_th instability and highlighting the need for careful control during fabrication.

Keywords: ultrathin oxide semiconductor, electron concentration, high-energy metal deposition, localized annealing, threshold voltage