Effects of substrate temperature on dielectric and structural properties of Ti and Er co-doped HfO2 thin films

We report dielectric and structural properties of Ti and Er co-doped HfO2 (HfTiErOx) thin films at different substrate temperatures. The film at 400 °C substrate temperatures has the highest k value of 33, improved flat band voltage of −0.3 V, small hysteresis voltage and the significant interface-state density, which shows better dielectric properties for new high-k microstructure. XPS and XRD results reveal that Hf–Ti–Er–O bond may exist in addition with Hf–O, Hf–Er–O and Hf–Ti–O bonds, while the change in chemical structure and degradation of crystallization quality of HfO2 thin films are directly related to Ti and Er co-doping.

► We report a method to improve the dielectric properties of HfO2 gate oxide. ► Incorporation of Ti and Er atoms into the HfO2 oxide results in forming of HfTiErOx high-k thin films oxide. ► Capacitance–Voltage measurements demonstrate the better dielectric properties. ► XPS and XRD were also carried out for existence of HfTiErOx structural properties. ► It could be used for high-k dielectric for future CMOS device.