Surface-tension-tailored aqueous ink for low-temperature deposition of high-k HfO2 thin film

In this paper, solution-based deposition of HfO2 thin film at low temperature was demonstrated. By using aqueous HfCl4 solution, the precursor was effectively decomposed with low annealing temperature of 150 °C. Thus it is preferable to use this solution for dielectric coating on flexible substrates. To achieve conformal coating on substrate, formic acid as a cosolvent was added to aqueous ink solution to reduce surface tension of the solution. Due to improved coating quality of HfO2 thin film, the fabricated HfO2 gate dielectric shows reliable breakdown characteristics and low leakage current.