Influence of Active Channel Layer Thickness on SnO2 Thin-Film Transistor Performance

Sol-gel processed SnO2 thin-film transistors (TFTs) were fabricated on SiO2/p+ Si substrates. The active channel layer was deposited by the sol-gel spin coating method. Precursor concentration influenced film thickness and surface roughness. As of precursor increased, films thicker smoother. device performance roughness layer. Decreased resulted in a with lower field-effect mobility, larger subthreshold swing (SS), increased threshold voltage (Vth), originating from free carrier increase trap sites. TFTs, an optimized 0.030 M precursor, had mobility 9.38 cm2/Vs, SS 1.99, Ion/Ioff value ~4.0 × 107, showed enhancement mode operation positive Vth, equal to 9.83 V.