Solution-Driven HfLaOx-Based Gate Dielectrics for Thin Film Transistors and Unipolar Inverters

In this article, the preparation of HfLaOx gate dielectric thin films by the spin coatingmethod is proposed. The in-depth physical properties of the as-prepared HfLaOx films were investigated as functions of annealing temperatures. Decided by the key performance indicators of current density, smooth surface, and areal capacitance of HfLaOx films with different annealing temperatures, optimized performance parameters with annealing temperature 550 degrees C have been obtained. To verify the feasibility of HfLaOx films as dielectric material, In2O3/HfLaOx thin-film transistors (TFTs) have been fabricated and device characterizations have been carried out. As a result, it has been detected that the In2O3/HfLaOx TFTs with optimized annealing temperature of 300 degrees C demonstrate superior electrical performance, including a high I-ON/I-OFF of similar to 10(6), a high mu FE of 17.09 cm(2)V(-1)s(-1), a low V-TH of 0.09 V, a small interfacial trap states (D-it) of 1.94 x 10(12) cm(-2), and a small threshold voltage shift of 0.23 V under PBS test and 0.11 V under NBS test after 3600 s bias stress, respectively. To confirm TFTs' potential applications in logic circuits, a resistor- loaded inverter was integrated and the maximum voltage gain of 7.60 was demonstrated at an ultra-low operating voltage of 2.5 V. Current observationshave indicated the great application prospects of solution-derived HfLaOx-gated TFTs in low-cost and excellent performance electronic devices.

Automated summary

This study proposed the preparation of HfLaOx gate dielectric thin films by the spin coating method and investigated their physical properties. Optimized performance parameters with annealing temperature of 300 degrees C were achieved for superior electrical performance, showing potential applications in logic circuits.