Overturning Size Effects in Ferroelectric Thin Films

Descripción del proyecto

Materiales ferroeléctricos para aumentar la eficiencia de la electrónica

El equipo del proyecto OSE-Ferroelectrics, financiado por las acciones Marie Skłodowska-Curie, pretende mejorar la eficiencia energética de dispositivos electrónicos, como transistores y dispositivos de memoria, mediante el uso de materiales ferroeléctricos. Uno de los principales retos de los dispositivos ferroeléctricos es el efecto negativo de la reducción del espesor sobre las propiedades críticas, como la polarización remanente, la tensión coercitiva y la corriente de fuga. En OSE-Ferroelectrics se abordarán estas cuestiones adaptando el diseño de la heteroestructura y realizando un seguimiento de las propiedades resultantes. Se utilizarán métodos ópticos y de sonda de barrido para evaluar localmente las propiedades cristalinas y ferroeléctricas. La evaluación independiente de la estructura electrónica ayudará a comprender el transporte de carga a través de las interfaces ferroeléctricas. Los resultados del proyecto podrían tener importantes implicaciones para la integración de los óxidos ferroeléctricos en la industria de los semiconductores.

Objetivo

The rapid increase in power consumption for data collection, storage and processing drives a global interest in finding new energy-efficient device paradigms. Ferroelectric materials can provide energy-efficient solutions for targeted applications such as transistors based on polarization-induced negative capacitance or memory devices based on polarization-controlled resistive switching. The crucial properties of ferroelectric-based heterostructures in electronic applications are remanent polarization, coercive voltage and leakage current because they limit the ON/OFF ratio, energy efficiency and charge transport properties of any device. However, uncompensated bound charge and defects at ferroelectric interfaces result in polarization suppression, increase of coercive voltage and uncontrolled charge carrier formation. The purpose of OSE-Ferroelectrics is to assess the possibility of tackling these size effects in ferroelectric thin films. In OSE-Ferroelectrics, I propose a path to an ambitious goal of overturning ferroelectric size effects by tailoring the heterostructure design and tracking the resulting crystal, electronic and ferroelectric properties. The two cornerstones of the proposal are: (i) adoption of combination of scanning-probe and optical techniques to locally evaluate the crystal, defect, and ferroelectric properties, and (ii) use of independent evaluation of electronic structure, charge carrier concentration and mobility to understand the charge transport properties across ferroelectric interfaces. The research questions and methods addressed in OSE-Ferroelectrics will advance the knowledge of ferroelectric size effects, bring attention to semiconducting properties of ferroelectric layers, and reveal routes for enhancing performance of ferroelectric memory devices. Ultimately, the results of this project would have important implications for the integration of oxide ferroelectrics into the semiconductor industry.