Vertical Channel-All-Around (CAA) IGZO FET With Recessed Source/Drain Structure to Improve Contact Characteristics

We proposed recessed source/drain(S/D) structure for vertical channel-all-around (CAA) IGZO FET to introduce contact interlayer and improve its contact characteristics. The IZO interlayer introduced between S/D and IGZO helps to reduce the contact resistance, and boosting the performance of CAA IGZO FET. The fabricated CAA IGZO FETs with 8 nm IZO interlayer show an average Ion @ V ${}_{\text {th}}+1$ V of $32.6~\mu $ A/ $\mu $ m, SS of 86 mV/dec, and Vth of - 0.06 V. The Schottky barrier height ${q}\phi _{B}$ is extracted to be reduced from 170 meV to 65 meV by introducing the contact interlayer, which confirms the improvement of contact characteristics.