Oxygen incorporated solution-processed high-κ La2O3 dielectrics with large-area uniformity, low leakage and high breakdown field comparable with ALD deposited films

Abstract

Low-power, form-free electronics require low-temperature and solution-processed high-κ dielectric materials with extremely low leakage current and good flexibility, which is still very challenging. For example, the large band-gap material La₂O₃ has been hampered from low-power electronics applications due to the poor stability and inability to be solution-processed. Here, we develop oxygen-incorporated solution-deposition to obtain a high-κ La₂O₃ dielectric film at a low temperature (120 °C). The thin film exhibits a uniform large area, a high-κ value (>12), a large band gap (>6.3 eV), a high breakdown electric field (>7 MV cm⁻¹), and a very low leakage current (10⁻⁸ A cm⁻² at 1 MV cm⁻¹) with excellent and stable insulating characteristics comparable with ALD deposited films. This method efficiently improves the chemical reaction and wettability of the precursor solution for densification and is also applicable for other high-κ dielectric materials like HfO₂ and ZrO₂. The film endures compressive strain at the limit of the PET substrate (∼2.5%) and enables flexible CMOS circuits with stable organic thin-film transistors (OTFTs) that exhibit a high gain (>90), a low operation voltage (2 V), and a low static power consumption (∼0.5 nW). The excellent characteristics enable the presented film and method to generally advance low-power and high-performance electronics with printable and flexible properties.