Title :
Effect of rare earth elements doping on the electrical properties of (Ba,Sr)TiO3 thin film capacitors
Author :
Kamehara, Nobuo ; Kwihara, Kazuaki
Author_Institution :
Fujitsu Quality Lab. Ltd., Kawasaki
Abstract :
Barium strontium titanate (BST) thin film capacitors are being intensively investigated for tunable microwave devices, because of their high permittivity, low dielectric loss in the microwave region and field dependent permittivity. This study investigates the effect of rare earth elements doping on the electrical properties of BST thin film capacitors. BST thin films were deposited by an RF magnetron sputtering technique on Si wafers. BST films were prepared with Y concentrations of 0-5%. Lattice parameters were measured using synchrotron radiation X-ray analysis. The results show that Y doped BST thin film capacitors exhibit not only significantly higher permittivity but also low leakage current density as compared to nominally undoped capacitors. X-ray diffraction results show the film strain state strongly depends on film composition with tunability decreasing with increasing tensile strain.
Keywords :
X-ray diffraction; barium compounds; current density; dielectric losses; doping; leakage currents; low-k dielectric thin films; permittivity; sputtering; strontium compounds; thin film capacitors; yttrium; (Ba,Sr)TiO3 thin film capacitors; BaSrTiO3:Y; RF magnetron sputtering; Si; X-ray diffraction; barium strontium titanate; dielectric loss; leakage current density; permittivity; rare earth elements doping; synchrotron radiation X-ray analysis; tensile strain; Barium; Binary search trees; Capacitors; Dielectric losses; Dielectric thin films; Doping; Microwave devices; Permittivity; Sputtering; Tensile strain;
Conference_Titel :
VLSI Packaging Workshop of Japan, 2008. VPWJ 2008. IEEE 9th
Conference_Location :
Kyoto
Print_ISBN :
978-1-4244-3498-5
DOI :
10.1109/VPWJ.2008.4762225
