Improving the dielectric losses of (Ba,Sr)TiO3 thin films using a SiO2 buffer layer

The efficient use of ferroelectric thin films in rF agile devices faces several limits. One of them is the dielectric losses which are usually above 1%, i.e. above the threshold as set by the electronic industry. Following the same route as for bulk ceramics, we have processed composite stacks made of BST/SiO2 multilayers using radio-frequency magnetron sputtering. Doing so, we were able to repetitively achieve dielectric losses of 0.1% while keeping a high dielectric susceptibility and a suitable tunability.