Rigorous extraction tunability of Si-integrated Ba0.3Sr0.7TiO3 thin film up to 60 GHz

Abstract

400-nm-thick Ba0.3Sr0.7TiO3 thin films are deposited on high resistivity silicon by in situ radio frequency magnetron sputtering. Coplanar waveguides with 1 μm slot width are designed, with accurate knowledge frequency losses behavior, to determine ferroelectric thin-films properties up to 60 GHz. Permittivity, loss tangent, and tunability are extracted through measurements and home made finite element analysis. Tunability of 33% and 29%, with 30 V maximum applied voltage (electric field of 300 kV/cm), are measured at 5 GHz and 60 GHz, respectively, while the dielectric losses evolve from 0.5% to 5%. A brief highlight is proposed about tunable silicon integrated quarter wavelength transformer potentialities for impedance matching.

Microwave evaluation of Pb0.4Sr0.6TiO3 thin films prepared by magnetron sputtering on silicon: Performance comparison with Ba0.3Sr0.7TiO3 thin films

“…8,9 This method was initially optimized for the BST thin film (e 0 BST % 300), so it is necessary to take some precautions before quantifying this with PST. Indeed, for PST thin films, our measurements at low frequencies show a permittivity of between 450 and 550.…”

Dielectric relaxation analysis of Pb(Zr0.54,Ti0.46)O3 thin films: Electric field dependence

“…As a comparison, in previous studies, for example, in the case of the characterization of BST thin films, we have obtained a maximum of 5% relative dispersion on the same frequency band (0.08%/GHz). 16 Of course, this very high dispersion is directly related to the dielectric losses. Indeed, the dielectric losses that we display in terms of loss tangent (tan d ¼ e 00 / e 0 ) exceed 50% in the worst case.…”

“…It should be mentioned that we have already qualified BST thin films in terms of permittivity and tunability at microwave frequencies. [16][17][18] So it would have been interesting to complete the dielectric characterizations by studying the relaxation time. Nevertheless, given the low level of losses in the case of BST, frequencies in the range of several hundred of GHz would have been required (about 800 GHz) to make the relaxation time measurable.…”

Effect of Zn Doping on the Microstructures and Dielectric Properties of BaTi0.9Sn0.1O3Ceramics

“…Due to this feature, ferroelectrics can be applied to various devices, such as oscillators, delay lines, filters, phase shifters and so on [1][2][3][4][5]. Among the microwave tunable materials, barium strontium titanate (BST) was regarded as a favorable dielectric and has been widely investigated [5,6].…”