Low Temperature Deposition of High Performance Lead Strontium Titanate Thin Films by in situ RF Magnetron Sputtering

Abstract

Highly (100) oriented lead strontium titanate (Pb 0.4 Sr 0.6 TiO 3 ) thin films were deposited on LaNiO 3 -coated Si substrate via radio-frequency magnetron sputtering method with substrate temperature ranging from 300 to 500°C. The PST thin films were crystallized at a temperature as low as 300°C, which may result from the well-controlled stoichiometry and the in situ crystallization on seed layer. At an electric field of 400 kV/cm, high tunability of 43% and 57% can be achieved for PST films deposited at 300°C and 500°C, respectively. Moreover, the dielectric response shows weak frequency dependence and the loss factor stays relatively low. The results suggest that such films should be promising candidate for the microwave tunable devices compatible with the current Si technology.

Optical and dielectric studies on radio frequency sputtered Gd2O3 doped K0.5Na0.5NbO3 thin films for nonlinear photonic and microwave tunable device applications

“…Relatively low and slow increase of leakage current density (1.47 Â 10 À8 A/ cm 2 at 0 kV/cm, and 4.06 Â 10 À6 A/cm 2 at 153 kV/cm) is obtained for the film deposited under 100% OMP, which is due to the highly denser surface morphology and good crystallinity presented in the film. The obtained leakage current densities were comparable the highly (001) oriented KNN thin films (~10 À6 A/cm 2 at 150 kV/ cm) prepared by using rf magnetron sputtering technique [56,57] and found to be lower (~10 À4 A/cm 2 at 150 kV/cm) as compared to the films reported by Wu et al [65]. The abrupt increase of leakage current density 3.32 Â 10 À5 A/cm 2 , and 1.12 Â 10 À4 A/cm 2 at 153 kV/cm was observed in the 0% and 50% OMP films, respectively.…”

“…The film deposited under pure argon plasma shown the (110) preferred orientation and with increasing the OMP, the (001) orientation as well as the tetragonality ratio found to be enhanced. The obtained ε r and tand are comparable to the highly (001) oriented KNN films (ε r ¼ 551 and tand ¼ 0.03 at 100 kHz) [56] and slightly lower compared other films prepared using rf magnetron sputtering [57,58]. Wang et al reported the dielectric properties (ε r ¼ 420e660 and tand ¼ 0.026e0.042 at 100 kHz) of Co doped KNN thin films prepared using chemical solution deposition method [59].…”

“…Above 38 kV/cm, the leakage current density increases abruptly and the obtained slope values are found to be 3.81, 4.20, and 3.34 at 192 kV/cm for the films deposited under 0%, 50%, and 100% OMPs, respectively. Therefore, it can conclude that the space charge limited current (SCLC) is the dominant conduction mechanism in the KNN1G thin films [56,57,64]. With further increase in the electric field, a found to be enhanced to 4.40 for 0% OMP thin film, and linearly decreases to 1.10 for the film deposited in pure oxygen plasma.…”

Dielectric enhancement of PbZr0.3Ti0.7O3/LaNiO3 multilayer thick film

“…The LaNiO 3 (LNO) with a pseudocubic perovskite structure is an excellent candidate materials for electrodes and buffers in perovskite ferroelectric thin films. It provides better lattice match with ferroelectric thin films and can improve the interface quality and the electrical properties of the thin films, which also reduce the atomic dislocations and crystallization temperature of PZT thin films . However, few studies on the multicycle PZT/perovskite oxide layer thick films were reported.…”

Multilayer thin films with compositional PbZr0.52Ti0.48O3/Bi1.5Zn1.0Nb1.5O7 layers for tunable applications

“…Ferroelectric materials are attractive materials for the applications in tunable devices at radio and microwave frequencies due to their high dielectric constant and agile feature under an external electric field123. A potential application of ferroelectric materials is in microwave tunable devices, including tunable mixers, delay lines, filters, and phase shifters for steerable antennas4567.…”