Abstract
Amorphous CaZrO
x
, ZrAl
x
Si
y
O
z
and HfAlO
x
complex high-k dielectric films are deposited by pulsed laser deposition, and their microstructural characteristics and interfacial reactions between deposited films and Si substrates during high temperature annealing processes are investigated by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. An essential finding is that nano-scale phase separation appears to be a common phenomenon for these amorphous films. The nonstoichiometric ZrO
x
or HfO
x
clusters precipitating from the amorphous matrix either react with silicon on the interface to form silicate or silicide interfacial layer, or nucleate and grow into nanosized crystals embedded in the outer layer of the dielectric films, which degrades the electrical performances of films.