Balanced Performance Enhancements of a-InGaZnO Thin Film Transistors by Using All-Amorphous Dielectric Multilayers Sandwiching High-k CaCu₃Ti₄O₁₂

The requirements of low power consumption and fast operation have necessitated the development of thin film transistors (TFTs) with exploration of new dielectric materials. Here, the unprecedented integration of high-κ dielectric CaCu₃Ti₄O₁₂ is reported, yielding significant enhancements in the performance of amorphous InGaZnO TFTs. Using a multilayer structured amorphous Al₂O₃/CaCu₃Ti₄O₁₂/Al₂O₃ dielectric configuration, the performance of the transistors is greatly improved as highlighted with high saturation mobility ('10 cm² Vs⁻¹), high on/off current ratio (3.8 × 10⁷), low threshold voltage (≈0.51 V), and low subthreshold swing (≈0.45 V decade⁻¹). The balanced performance enhancements are attributed to the lower density of interfacial/bulk trap states and sufficient band offsets.