Atomic layer deposition (ALD) offers a viable route for the growth of thin and conformal films over 3D topographies and is becoming attractive as a method to grow films thin enough, and with sufficient dielectric constants (k), for the fabrication of next-generation dynamic random memories. The authors used ALD to grow thin (≤15 nm) Ba_xSr_1 − xTiO₃ (BST) films that are epitaxially integrated to SrTiO₃ (001) (STO) and Nb-doped SrTiO₃ (001) (Nb:STO). Films of three compositions, which are x ∼ 0.7, 0.5, and 0.3, and thicknesses of 7.8–14.9 nm were grown at 1.05 Torr and 225 °C using barium bis(triisopropylcyclopentadienyl), strontium bis(triisopropylcyclopentadienyl), titanium tetraisopropoxide, and H₂O. Film compositions were controlled by changing cycle ratios (Ba:Sr, Ba:Ti, and Sr:Ti) and confirmed by in situ x-ray photoelectron spectroscopy. Films were amorphous as-deposited and required postdeposition vacuum annealing at 650–710 °C to crystallize. Epitaxy was confirmed with x-ray diffraction and transmission electron microscopy. Only BST (00l) out-of-plane diffraction signals were detected. Capacitance-voltage (C-V) measurements revealed that BST thin films grown by ALD have dielectric constant values ranging from 210 for Ba_0.71Sr_0.26TiO₃ to 368 for Ba_0.48Sr_0.43TiO₃.

中文翻译：

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通过原子层沉积在SrTiO3（001）衬底上高kBaxSr1-xTiO3薄膜的外延生长

原子层沉积（ALD）为3D形貌上的薄膜和保形膜的生长提供了一条可行的途径，并且作为一种足够薄且具有足够介电常数（k）的薄膜生长方法，正变得有吸引力，可用于下一代制造动态随机记忆。作者使用ALD来生长薄（≤15nm）Ba _x Sr _{1-  x} TiO ₃（BST）薄膜，这些薄膜外延集成到SrTiO ₃（001）（STO）和掺Nb的SrTiO ₃（001）（Nb：STO） ）。三种组成的胶卷，即x 使用双（三异丙基环戊二烯基钡），双（三异丙基环戊二烯基锶），四异丙氧基钛和H ₂ O在1.05 Torr和225°C下生长约0.7、0.5和0.3，厚度为7.8-14.9 nm 。改变循环比（Ba：Sr，Ba：Ti和Sr：Ti）并通过原位X射线光电子能谱确认。薄膜是非晶态沉积的，需要在650–710°C下进行沉积后真空退火才能结晶。通过X射线衍射和透射电子显微镜确认了外延。仅检测到BST（00 l）面外衍射信号。电容电压（CV）测量表明，通过ALD生长的BST薄膜具有介电常数值，范围从Ba _0.71 Sr _0.26 TiO _3的210到Ba _0.48 Sr _0.43 TiO _3的368 。