Hisao Watarai

Electric Properties of SrTiO3 Thin Films Prepared by RF Sputtering

Dielectric SrTiO 3 thin films have been prepared on Pt/SiO 2 /Si-wafer by means of a conventional rf-magnetron sputtering technique. Electric and dielectric properties of the films have been studied. It is demonstrated that the leakage current of the films is strongly dependent on the atmosphere during deposition. The SrTiO 3 film 75 nm in thickness fabricated in pure O 2 of 26.6 Pa at 600°C obtained the lowest leakage current density of 4.0×10 −9 A/cm 2 at 2 V. Analysis of the leakage current vs applied voltage characteristic indicated that the conduction in the higher electric field was due to the Pool-Frenkel emission

The Effect of Mn Addition on Dielectric Properties and Microstructure of BaO-Nd2O3-TiO2 Ceramics

The dielectric properties and microstructures were investigated in ceramics of BaONd2O35TiO2 to which various amounts of Mn were added. Although the behavior of the dielectric constant was independent of additional Mn, the temperature coefficient was improved considerably. The phases which were observed in these ceramics were characterized by means of electron probe microanalysis (EPMA) and X-ray diffraction method (XRD) in microareas. The shapes and areas of the phases varied with Mn content. The dielectric properties seemed to be mainly related to the properties of the matrix phase.

Preparation of Sr(Zr, Ti)O3 Ceramics and Their Dielectric Properties at Microwave Frequencies

Powder of the dielectric ceramic Sr(Zr, Ti)O 3 was prepared by a new chemical method using TiO 2 powder. The obtained fine and well-dispersed powder had good sinterability. The microscopic compositional uniformity in the sintered body was estimated by WDX, and the dielectric properties were measured at 6 GHz and 1 MHz. The samples prepared by the chamical method had excellent uniformity and a Q value (1/tan δ) 2.5 times that of the samples prepared by the conventional method