Abstract: Disclosed is a process for generating thin-film barium strontium titanate (“BST”) having a lattice comprised of a plurality of A lattice sites and a B lattice site, in which a yttrium may be found at a location of at least one location of the plurality of A lattice sites or the B lattice site. In one embodiment, the plurality of A lattice sites comprises a location for at least one from a group consisting of barium and strontium. In one embodiment, the B lattice site comprises a location for a titanium. A capacitor having the inventive Y-doped BST dielectric is also disclosed.

Abstract: Parallel plate tunable varactors having a bulk capacitance contribution to a total capacitance increased compared to a fringing capacitance contribution are disclosed. The contribution of the bulk capacitance to the total capacitance of an exemplary BST varactor is increased by increasing the area/perimeter ratio of the active region, thereby improving the tunability and other properties of the varactor. In an exemplary embodiment, an active region of the varactor has a lateral shape with a perimeter that is less than a perimeter of an equivalent area square. In various exemplary embodiments, the shape of the active region may be substantially circular or substantially octagonal. Methods for fabricating and designing such varactors are also disclosed.