Effects of Different Annealing Gases on Pentacene OTFT With HfLaO Gate Dielectric

摘要

Pentacene organic thin-film transistors (OTFTs) with HfLaO high-$kappa$ gate dielectric were fabricated. The dielectric was prepared by a sputtering method and then annealed in $hbox{N}_{2}$, $ hbox{NH}_{3}$, $hbox{O}_{2}$, or NO at 400 $^{circ}hbox{C}$. The carrier mobility of the $hbox{NH}_{3}$-annealed OTFT could reach 0.59 $hbox{cm}^{2}/hbox{V}cdothbox{s}$, which is higher than those of the other three devices. Moreover, the $hbox{NH}_{3}$ -annealed OTFT obtained the smallest subthreshold swing of 0.26 V/dec among them. Furthermore, $hbox{1}/f$ noise measurement indicated that the $hbox{NH}_{3}$-annealed OTFT achieved the smallest $hbox{1}/f$ noise. All these should be attributed to the improved interface between the gate dielectric and the organic semiconductor associated with the passivation effects of the $hbox{NH}_{3}$ annealing on the dielectric surface.