Study on dielectric and tunable properties of Cr-doped Ba0 .6Sr0.4TiO3 thin films by rf sputtering

Effects of substrate temperatures on quality of BaO-SrO-ZnO-Nb2O5 thin films by RF-sputtering using Zn-enriched (Ba0.3Sr0.7)(Zn1/3Nb2/3)O3 ceramic target

“…The binding energy peaks corresponding to Ba3d 5/2 and Binding Energy/eV elements, this behavior seems to be unfavorable for the formation of the stoichiometry thin films, which is also commonly reported by the references [2,8,9,17]. Figure 5 shows the SEM images of the thin films sputtered at (a) room temperature; (b) 200°C; (c) 400°C; and (d) 600°C.…”

“…However, there exist many problems for these thin films, such as the composition discrepancy between the target and the thin films (i.e., serious Zn-loss), and oxygen-vacancies [6,7]. Taking into account that a major barrier in the widespread use of these thin films in a number of high-frenquency applications is their high leakage currents determined by structural defects like grain boundaries and oxygen vacancies [2,4,[8][9][10][11][12][13][14], it is urgent for researchers to prepare a dense thin film with high crystalline quality. Therefore, in this article, a Zn-enriched target comprised of a homogeneous mixture of 1 mol (Ba 0.3 Sr 0.7 )(Zn 1/3 Nb 2/3 )O 3 and 1 mol ZnO was utilized to compensate the volatilization of ZnO during the process of sputtering and annealing [6,7], next, the ceramic thin films on SiO 2 (110) substrates were prepared by radio frequency (RF) magnetron sputtering, and the effects of substrate temperatures on the microstructures, morphologies, grain sizes, RMS roughness values and chemical compositions of the thin films were studied in detail as a progress report of the results published previously in the other paper [15].…”

Structures and Tunability of Ba0.5Sr0.5TiO3/Bi1.5Zn1.0Nb1.5O7Multilayer Thin Films Grown on Pt/Al2O3Substrates

“…The dielectric constant of BST/BZN multilayer thin films increased with annealing temperature and reached a value of 69 at 750 • C. The dielectric constants of BST/BZN multilayer thin films are smaller than that of pure BST thin films. The smaller dielectric constants of the BZN/BST thin films can be a result of the presence of BZN phase in BST, which is similar to that observed in the cases of BST doped with oxides[4][5][6][7]. The BST/BZN multilayer thin films can be considered as the BST and BZN capacitors are connected in series.…”

“…For optimal performance of the tunable devices it is important to grow a material with high dielectric tunability, low dielectric losses, and low temperature dependence of the dielectric permittivity in the operation frequency and temperature ranges of the device. To improve the BST material performance for the use of tunable devices many efforts have been tried, such as doping [4][5][6][7], fabrication of composite and multilayered structure [8][9], etc.…”

Influence of annealing times on morphological characteristics of ceramic thin films by RF-magnetron sputtering using Zn-enriched (Ba0.3Sr0.7)(Zn1/3Nb2/3)O3 ceramic target

“…Our group has studied ceramic thin films fabricated by radio frequency (RF) magnetron sputtering using 1 mol (Ba 0.3 Sr 0.7 )(Zn 1/3 Nb 2/3 )O 3 mixed with 1 mol ZnO ceramic as target, we have studied the effects of oxygen partial pressures and the annealing temperatures on the microstructures and the compositions of the BaO-SrO-ZnO-Nb 2 O 5 thin films [6][7][8]. Considering the fact that a larger grain size could be a positive factor for improving dielectric properties [9,10] and a major barrier in the widespread use of these films in a number of high-frequency applications is their high leakage currents determined by the structural defects as grain boundaries and oxygen vacancies [4,9,10], it is urgent for us to prepare a crack-free thin film with smooth surface and large grain size. In this paper, we studied the influence of the annealing times on the grain sizes, the microstructures and the surface morphologies of the ceramic thin films in detail as a progress report of the results published previously in the other papers [6][7][8].…”