A multi-layered unit according to the present invention includes a support substrate
formed of a silicon single crystal, a barrier layer formed on the support substrate
of silicon oxide, an electrode layer formed on the barrier layer of platinum, a
buffer layer formed on the electrode layer of a dielectric material containing
a bismuth layer structured compound having a composition represented by Bi4Ti3O12,
having an excellent orientation characteristic and oriented in the c axis direction,
and a dielectric layer formed on the buffer layer of a dielectric material containing
a bismuth layer structured compound having a composition represented by Bi4Ti3O12,
having an excellent capacitor characteristic and oriented in the c axis direction.
Since the thus constituted multi-layered unit includes a dielectric layer containing
a bismuth layer structured compound oriented in the c axis direction, in the case
of, for example, providing an upper electrode on the dielectric layer, thereby
fabricating a thin film capacitor and applying a voltage between the electrode
layer and the upper electrode, the direction of the electric field substantially
coincides with the c axis of the bismuth layer structured compound contained in
the dielectric layer. As a result, since the ferroelectric property of the bismuth
layer structured compound contained in the dielectric layer can be suppressed and
the paraelectric property thereof can be fully exhibited, it is possible to fabricate
a semiconductor device by incorporating a thin film capacitor having a small size,
large capacitance and an excellent dielectric characteristic into the support substrate
of a silicon single crystal together with other devices such as a field effect
transistor, a CPU and the like.
