Microstructure of HfO2 and HfxSi1-xOy Dielectric Films Prepared on Si for Advanced CMOS Application

We analyzed microstructure of as-deposited and rapid thermal annealed HfO
₂
and Hf
_x
Si
_1-x
O
_y
dielectric films with Ru gate electrode. As-deposited films exhibited dielectric constant 12 and 20 for Hf
_x
Si
_1-x
O
_y
and HfO
₂
, respectively. TEM and grazing incidence XRD revealed that as-deposited HfO
₂
films have polycrystalline character, while Hf
_x
Si
_1-x
O
_y
films are amorphous. Rapid thermal annealing makes favourable growth of monoclinic HfO
₂
phase in HfO
₂
films and tetragonal or orthorhombic phase in Hf
_x
Si
_1-x
O
_y
films