Interface contribution to the capacitance of thin-film Al-Al sub 2 O sub 3 -Al trilayer structures.
01 January 1987
A dual-gun reactive ion-beam sputtering technique has been used to reproducibly fabricate Al sub 2 O sub 3 dielectrics with low electrical loss for controlled thicknesses ranging from approximately 10angstroms to 360angstroms. The linear dependence of the reciprocal capacitance on dielectric thickness of Al-Al sub 2 O sub 3-Al trilayer structures incorporating this dielectric reveals a significant contribution from an interfacial capacitance in series with the geometric capacitance. Room-temperature measurements of both the dc resistance and the frequency-dependent complex impedance demonstrate that, with respect to bulk, there is an enhanced frequency-dependent dielectric loss associated with this interfacial capacitance.