Electronic properties of the silicon-thermally grown tantalum oxide interface

MOS capacitance measurements showed that the Si-Ta
2
O
5
interface prepared by thermal oxidation at ∼530°C of vacuum deposited Ta film followed by a heat treatment at 350°C in N
2
-H
2
is characterized by a negative "oxide" charge (6 × 10
¹¹
e/cm
^-2
at flat-band) and by an interface state density of ∼ 1 × 10
¹²
cm
^-2
(eV)
^-1
. The room temperature instability is small. The breakdown strength is >8 × 10
⁶
V/cm.