Deposition Characteristics of (Ba, Sr)TiO 3 Thin Films by Liquid Source Metal-Organic Chemical Vapor Deposition at Low Substrate Temperatures

• Published in: Japanese Journal of Applied Physics 1997-11, Vol.36 (11R), p.6946
• Main Authors: Kang, Chang Seok, Cho, Hag-Ju, Hwang, Cheol Seong, Lee, Byoung Taek, Lee, Ki-Hun, Horii, Hideki, Kim, Wan Don, Sang In Lee, Sang In Lee, Moon Yong Lee, Moon Yong Lee
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.36.6946

The deposition characteristics of (Ba, Sr)TiO 3 (BST) thin films using a liquid source metal-organic chemical vapor deposition on a 6-inch-diameter Pt/SiO 2 /Si wafer were investigated. Ba(DPM) 2 tetraglyme, Sr(DPM) 2 tetraglyme and Ti(DPM) 2 (O-i-Pr) 2 , dissolved in n-butyl acetate, were used as the sources of Ba, Sr and Ti, respectively. Step coverage, within-wafer uniformities in composition and thickness of the BST films were investigated as a function of substrate temperatures ranging from 420° C to 570° C. As the substrate temperature decreased, the step coverage improved, whereas the within-wafer uniformities degraded. From BST films deposited in a temperature range from 450° C to 480° C, good step coverage (>80%), as well as good within-wafer uniformity were obtained. However, in that temperature range, hazy deposition was observed due to many humps on the surface. The humps are an agglomeration of crystalline grains and are a few hundred Å in diameter, which have a Ti-rich composition compared to flat film region.