Identification number: LZP-2024/1-0676
Type: Latvian Council of Science Fundamental and Applied Research project
Duration: 01.01.2025. - 31.12.2027.
Project Leader: Dr. phys. Katrīna Laganovska, Institute of Solid State Physics University of Latvia (ISSP UL)
Total funding: 299 973 EUR
Project summary:
The discovery of ferroelectricity in hafnium oxide based binary oxides in 2011 jump-started the second wave of intensive research of ferroelectric devices and, especially, ferroelectric field-effect transistors (FeFET) and ferroelectric random-access memories (FeRAM). The main challenge for hafnia ferroelectrics is the stabilization of the ferroelectric phase, the polar orthorhombic Pca21. Three primary factors influence this phase and its properties: dopants, defects, and tensile stress. While each of these factors affect the phase and electrical properties, the formation of oxygen vacancies can both stabilize the orthorhombic phase, and also be a detrimental and often is an undesirable byproduct. In order to be able to control the amount, properties and effect of oxygen vacancies on the orthorhombic phase stability and device reliability a thorough understanding of the formation and characteristics of these defects is necessary. The main goal of the project is to determine the concentration, spatial distribution, charge, coordination number and activation energies of the oxygen vacancies present in hafnia-based materials and their impact on the resulting electrical and structural properties for the first time experimentally. Pure and doped HfO2 based materials will be synthesized using microwave assisted hydro-/solvo-thermal synthesis. Among other methods, XPS, TL, PFM and XAS will be used to study the oxygen vacancies.