Hafnium dioxide (HfO2) is an oxide of hafnium, which is a white solid at room temperature and pressure. Melting point is 2780-2920K. Boiling point 5400K. The coefficient of thermal expansion is 5.8 x 10-6/. It is insoluble in water, hydrochloric acid and nitric acid, but soluble in concentrated sulfuric acid and hydrofluoric acid.
It is prepared by thermal decomposition or hydrolysis of hafnium sulfate, hafnium chloride and other compounds. It is the raw material for producing metal hafnium and hafnium alloy. Used as refractory, anti-radioactive coating and catalyst.
Hafnium dioxide (HfO tamping) is a kind of ceramic material with wide band gap and high dielectric constant. Recently, it has attracted great attention in industry, especially in the field of microelectronics. Because it is most likely to replace the gate insulating layer of metal oxide semiconductor field effect transistor (MOSFET), which is the core device of silicon-based integrated circuits, in order to solve the problem of traditional SiO tamping/Si structure in MOSFET. Dimensional limit of exhibition.