https://doi.org/10.1051/epjap/2009164
Annealing effects on microstructures of HfAlO/Si with a Ti capping layer
Department of Physics, Wenzhou University, Wenzhou 325027, P.R. China
Corresponding author: liwan_china@yahoo.com.cn
Received:
4
January
2009
Revised:
4
June
2009
Accepted:
24
July
2009
Published online:
2
October
2009
We report on microstructures of HfAl2O5 gate dielectric film grown
on Si substrate with a Ti capping layer treated with rapid thermal annealing
process. X-ray reflectivity, atomic force microscopy and X-ray photoelectron
spectroscopy are used to investigate the sample. Results show that a
Six(SiO
layer naturally forms at the interface between
the HfAlO layer and the Si substrate in the as-grown sample. With the help
of the Ti capping layer on the HfAlO/Si, the annealing treatment can
effectively remove the Six(SiO interface layer, which
enhances the capacitance of the dielectric film. On the other side, the
annealing process roughens the interfaces of the sample, which brings into
the increase of the leakage current. Higher temperature of the annealing
treatment results in rougher interfaces. Thus, the annealing temperature
should be chosen properly to improve the capacitance of the film, before the
interface roughening works to increase the leakage current. In this way, the
dielectric and structural properties of the samples can be optimized.
PACS: 61.05.cm – X-ray reflectometry (surfaces, interfaces, films) / 68.37.Ps – Atomic force microscopy (AFM) / 79.60.Dp – Adsorbed layers and thin films
© EDP Sciences, 2009
