Capacitance-Voltage Investigation of HfO2/Al2O3 Bilayered High-k Dielectrics on Si Nanomembrane

As essential building blocks for thin film transistors (TFTs), the metal-oxide-semiconductor (MOS) structure will be fundamentally important for understanding the effect of mechanical bending on TFTs. In this work, HfO2/Al2O3 high-k dielectric bilayers are deposited on Si nanomembranes (NM) by plasma-enhanced atomic layer deposition (PEALD), thus achieving vertical structured flexible MOS capacitors based on such composite gate stack on plastic substrates. Devices demonstrate outstanding capacitance-voltage (C-V) characteristics with nearly no hysteresis voltage, a suppressed stretch-out effect and low frequency dispersion, highlighting HfO2/Al2O3 stacked films as a promising dielectric alternative for high performance bendable and stretchable electronics.