Abstract The monolithic integration of metal oxide thin films with conventional semiconductors like silicon and germanium enables new functionalities to be introduced to semiconductor devices. In this regard, we used pulsed laser deposition (PLD) to grow epitaxial strontium titanate (STO) films on Ge (0 0 1) single crystal. The study of the structure and phase of STO films and of Ge(0 0 1) was performed using in situ X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). By optimizing surface preparation and deposition conditions, it was possible to grow epitaxial STO films with a sharp interface without the presence of interfacial amorphous oxide layer. The effects of the Ge(0 0 1) surface substrate cleaning, growth temperature, oxygen partial pressure, and laser energy density on the growth of STO films are discussed. In particular, we find that PLD of STO on Ge(0 0 1) single crystal in the presence of O2 leads to growth of (1 0 0) and (1 1 0) planes while in its absence the growth is largely limited to the (1 1 0) plane.

中文翻译：

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使用脉冲激光沉积在锗衬底上生长外延钛酸锶薄膜

摘要 金属氧化物薄膜与传统半导体（如硅和锗）的单片集成使新的功能能够被引入到半导体器件中。在这方面，我们使用脉冲激光沉积 (PLD) 在 Ge (0 0 1) 单晶上生长外延钛酸锶 (STO) 薄膜。使用原位 X 射线光电子能谱 (XPS)、X 射线衍射 (XRD) 和高分辨率透射电子显微镜 (HRTEM) 对 STO 膜和 Ge(0 0 1) 的结构和相进行了研究。通过优化表面制备和沉积条件，可以在不存在界面非晶氧化物层的情况下生长具有尖锐界面的外延 STO 膜。Ge(0 0 1) 表面衬底清洗、生长温度、氧分压的影响，讨论了激光能量密度对 STO 薄膜生长的影响。特别是，我们发现在 O2 存在下 Ge(0 0 1) 单晶上 STO 的 PLD 导致 (1 0 0) 和 (1 1 0) 平面的生长，而在没有 O2 的情况下，生长主要限于(1 1 0) 平面。