[17a-W9_324-1~10] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

9:30 AM - 9:45 AM JST(12:30 AM - 12:45 AM UTC)English Presentation

[17a-W9_324-2] Effectiveness of gate dielectric AlO_x interlayer on electrical characteristics improvement in ultrathin InO_x FETs

〇CHIATSONG CHEN¹, Kasidit Toprasertpong², Toshifumi Irisawa¹, Wen-Hsin Chang¹, Shinji Migita¹, Yukinori Morita¹, Hiroyuki Ota¹, Tatsuro Maeda¹ (1.AIST, 2.the Univ. of Tokyo)

Keywords:

oxide semiconductor,ultrathin body channel,reliability

Oxide semiconductor channels have drawn much attention for back-end of line (BEOL) transistors to achieve monolithic 3D integration due to their excellent current drivability while maintaining low leakage current attributed to the wide bandgap property [1]. ALD-based InO_x channels are promising to provide a higher overdrive current against other oxide semiconductor materials even in ultrathin body conditions [2]. However, the issue of negative V_th in InO_x FETs due to impurity incorporation from the vicinity dielectric layer remains a challenge for practical implementation. In this work, we realize enhancement-mode InO_x FETs by inserting a thin AlO_x interlayer as a hydrogen barrier between InO_x channel and HfO_x gate dielectric. The 300℃ N₂ annealed InO_x FETs with AlO_x/HfO_x gate dielectric provides V_th of 0.26 V, SS factor of 65.8 mV/dec, and the V_th shift of +91 mV under 1-hour PBS.