Downscaling at submicrometer scale of the gap width of interdigitated Ba0.5Sr0.5TiO3 capacitors.

The goal of this work was to study the influence of shrinking the gap width between the fingers of interdigitated tunable capacitors (IDCs). Voltage control of the capacitance was achieved with a 500-nm-thick Ba0.5Sr0.

Characterization of doped BST thin films deposited by sol-gel for tunable microwave devices.

BST thin films with various dopants were grown by the sol-gel method on platinized silicon and MgO substrates. Their dielectric properties were investigated at low frequency (up to 1 MHz) on silicon with parallel-plate capacitors and at high frequency (up to 15 GHz) with interdigitated capacitors on MgO substrate. The results depend on the nature of the dopant and show that Mg is a very good candidate to reduce dielectric losses.