イオンビームスパッタリング法で作製した(Ba, Sr) TiO3薄膜のミリ波アニールによる結晶化

Abstract

(Ba, Sr)TiO3 films were deposited by ion beam sputtering and annealed by millimeter-wave heating to be crystallized. It was revealed that an oxygen ratio of gas introduced into an ion source influenced on both crystallinity and phases in the films and the ratio of Ar/O2 = 1 was the best. Films prepared by mixed gas (Ar/O2 = 1) were crystallized at 823 K by an electric furnace, which was about 100 K lower than values which other researchers reported. This could possibly be because ion beam sputtering enables to deposit films at lower pressure than other sputtering technique and as a result, contamination of films by sputtering gas like Ar is less. Additionally, the films were crystallized at quite low temperature of 723 K by millimeter-wave heating. Relative dielectric constants of the films prepared by both the electric furnace and millimeter-wave heating were measured and the value of millimeter-wave heated film was approximately 430, which was four times as high as that of the electric furnace.