Fig. 1. (Color online) Schematic cross-section and major processing steps of the SATG IGZO transistors.

Fig. 2. (Color online) (a) Transfer characteristics of SATG IGZO transistors with different Ls and (b) the corresponding L-dependences of V_ths. The inset shows the schematic cross-section of the transistor.

Fig. 3. (Color online) (a) L-evolutions of ΔV_th for SATG IGZO transistors with GI scaling down from 200 to 10 nm. ΔV_th = V_th(L) – V_th (L = 100 μm). (b) The schematic profile of carrier concentration from n⁺-type S/D to n⁻-type channel.

Fig. 4. (Color online) Transfer characteristics of SATG transistors with IGZO sputtered using Ar/O₂ ratios of (a) 47/3 and (b) 48/2, and corresponding L-dependences of (c) V_th and (d) R_SD/R_CH ratio (V_GS = 3.0 V).

Fig. 5. (Color online) (a) C−V characteristics of SATG IGZO transistors with different Ls. (b) L-dependence of V_{th_CV} for SATG IGZO transistors with 10 nm-thick GI. Inset shows the extraction method of V_{th_CV}.

Fig. 6. (Color online) (a) Transfer characteristics of bottom-gate IGZO transistors with various Ls, and (b) the corresponding L-dependences of V_ths. The inset shows the schematic cross-section of the transistor.