Abstract
The influence of thick
(
∼
10
nm
)
AlN overlayers on the interface structure and reactions in Si gate stacks with
Hf
O
2
dielectrics was investigated. Annealing caused a reduction of the interfacial
Si
O
2
at the Si interface. At high temperatures
(
∼
1000
°
C
)
a silicide reaction was observed at the
Hf
O
2
∕
Si
interface. No reactions were observed for stacks processed similarly but with WN or TiN overlayers instead of AlN. The reaction mechanisms, in particular, the role of oxygen deficiency of the
Hf
O
2
, and the consequences for the electrical properties are discussed.