Electrically stable low voltage ZnO transistors with organic/inorganic nanohybrid dielectrics

We report on the fabrication of top-gate ZnO thin-film transistors (TFTs) with organic and inorganic nanohybrid dielectric layers that take superlattice form in their inside structure. The nanohybrid dielectrics were prepared by the alternate deposition of organic self-assembled monolayer and oxide monolayer on sputter-deposited ZnO channel. With a 22-nm -thin Al Ox -based hybrid dielectric layer (∼130 nF cm2), our ZnO TFT showed a field mobility of 0.36 cm2 V s operating at 8 V, while the mobility increased up to 0.66 cm2 V s with a 22-nm -thin Al Ox -based/ Ti Ox -based/ Al Ox -based (5.5 nm11 nm5.5 nm and ∼220 nF cm2) triple hybrid layer under 2 V operation. Since both ZnO-TFTs display little gate hysteresis, we conclude that our nanohybrid dielectric approach is promising to achieve a gate-stable low voltage top-gate ZnO-TFTs.