摘要
用R.F.磁控溅射法在p—Si(100)衬底上沉积Ba0.5Sr0.5TiO3/RuO2异质结,BST薄膜的晶相和表面形貌用XRD和SEM分析,表明在衬底温度为550℃时,薄膜的结晶度高、表面粗糙、晶粒较大.电容器InGa/BST/RuO2的介电特性由ε-V特性和I—V特性描述.薄膜在零偏压下ε=230、tgδ≈0.03.低电场条件下,薄膜的漏电流随电压呈饱和特性,属电子跳跃传导,且通过改善薄膜的结晶度可减小该漏电流.高电场条件下,漏电流符合肖特基发射规律.
Ba0.5Sr0.5TiO3thin films were deposited by R.F. magnetron sputting on RuO2-coated silicon substrates. X- ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to study the phase and surface morphology of the BST films. The results indicate that the BST films deposited at 550 ℃ substrate temperature have higher crystallinity and rougher surface than that of the films deposited at 500 ℃. For dielectric measurements of the BST films, InGa/BST/RuO2 capacitors were fabricated . A 200 nm BST thin film deposited at 550 ℃ with O2/Ar= 5/5 ambience has a dielectric constant of 230 and a dissipation factor of 0.03 at zero bias volage. In the current-voltage curve of BST film deposited at higher substrate temperature, lower leakage current, density in the low bias region and narrower flat region (electron hopping conduction region) are obtained.
出处
《光电子技术与信息》
2004年第2期19-22,共4页
Optoelectronic Technology & Information
基金
湖北省自然科学基金资助项目(2003ABA066)
湖北省教育厅自然科学基金资助项目(2003A006)
关键词
BST薄膜
射频溅射
底电极
结晶度
介电特性
BST thin film
R. F. sputting
bottom electrode
crystallinity
dielectric property
