Publication date: Available online 5 January 2016
Source:Thin Solid Films
Author(s): Jieqiong Zhang, Hei Wong, Kuniyuki Kakushima, Hiroshi Iwai
Effects of thermal annealing on the interface reactions and the bonding structures of several CeO2 /La2 O3 stacked dielectrics were studied in detail based on x-ray photoelectron spectroscopy (XPS) measurements. Results indicated that the high-temperature annealing can enhance O, Ce, La and Si diffusion and result in the intermixing of CeO2 /La2 O3 stack, growth of interfacial silicates layer at the La2 O3 /Si interface. A small amount of Ce32 /La2 O3 and La2 O3 /Si interfaces during thermal annealing are proposed. The growth of low-k interfacial layer undoubtedly brings a great challenge for achieving the smallest equivalent oxide thickness (EOT) with superior interface properties. This investigation provides some additional information for possible performance optimization of the high-k gate dielectrics in the subnanometer EOT era.
Source:Thin Solid Films
Author(s): Jieqiong Zhang, Hei Wong, Kuniyuki Kakushima, Hiroshi Iwai
