Microstructure, optical and electrical properties of solution-derived peroxo-zirconium oxide gate dielectrics for CMOS application

Abstract

Solution-processed high-k gate dielectrics for metal-oxide-semiconductor (MOS) capacitor have been widely investigated with the objective of achieving high performance field effect transistors (FETs) for next-generation microelectronic device. In current work, the effect of postdeposition annealing temperature on the microstructure, optical and electrical properties of peroxo-zirconium oxide (ZrO2) gate dielectrics fabricated by a simple spin-coating method has been studied systemically. By means of characterization of spectroscopy ellipsometry and ultraviolet–visible spectroscopy, the thicknesses and optical constants of ZrO2 gate dielectrics have been determined precisely. The annealing temperature dependent electrical properties of ZrO2 films were determined by capacitance–voltage (C–V) and leakage current density–voltage (J–V) measurements. Based on the implementation as gate insulator, the solution-processed ZrO2-based MOS capacitor showed good and stable performances during annealing at 700°C. As a result, the dominant leakage conduction mechanism for optimized 700°C-annealed sample has been discussed in detail. Our results show the possibility of the solution-processed ZrO2 dielectric layer as a gate insulator for application in MOSFETs.