硅基钛酸钡纳米铁电薄膜的脉冲电子束沉积制备及表征
发布时间:2019-01-12 12:55
【摘要】:随着微电子集成电路的不断发展,光电子器件和传感器向微纳尺度发展,铁电薄膜因其特殊的铁电性能而在功能器件中得以广泛应用,并且提供了更多的调控机制和功能应用,因而吸引了广泛的关注。目前,广泛使用的铁电薄膜多为含铅薄膜,众所周知,重金属铅对环境和生命体不友好,因此人们在过去十年时间里一直致力于寻找无铅铁电材料。在这样的背景下,本论文将针对“无铅”铁电薄膜—钛酸钡薄膜展开一系列的研究探索。钛酸钡薄膜具有优异的铁电性能、压电性能以及光电性能。在探究其铁电性能时,钛酸钡薄膜通常被沉积在具有金属底电极的硅基底上,厚度多在百纳米级别以上,在十纳米尺度生长及性能研究方面的探究比较少。本论文使用脉冲电子束沉积技术在单晶硅基底上制备厚度为几十纳米的钛酸钡薄膜,探究其各项工艺参数对钛酸钡薄膜的表面形貌、组成成分、结构特性以及铁电性能等的影响。论文主要的研究工作和成果有:利用脉冲电子束沉积技术制备了厚度为几十纳米的钛酸钡薄膜,对其进行了材料表征并研究其铁电性能。用扫描电子显微镜以及原子力显微镜对其形貌进行表征可以发现钛酸钡薄膜表面较为平整均匀;用X射线衍射图谱分析其结晶取向性较好;用压电力显微镜观察其具有微观电畴。通过比较各工艺参数,我们发现当沉积时基底温度为700℃,在单晶硅基底上制备出的27.6 nm厚的钛酸钡薄膜具有非常好的宏观以及微观的铁电性能。当其厚度不断增加时,其宏观铁电性能被优化,薄膜内部的微观电畴更被易外加电场调控。本论文进一步研究了钛酸钡薄膜非原位热处理工艺对其各性能的影响。将使用脉冲电子束沉积技术制备好的钛酸钡薄膜在空气中长时间退火后发现,该热处理工艺可以改善钛酸钡薄膜中缺氧的状态,其结晶取向性增强,微观电畴的体积也有显著增大,而且其宏观铁电性能也有显著提高。
[Abstract]:With the continuous development of microelectronic integrated circuits and the development of optoelectronic devices and sensors to micro and nano scale, ferroelectric thin films are widely used in functional devices because of their special ferroelectric properties, and provide more control mechanisms and functional applications. As a result, it attracted wide attention. At present, the widely used ferroelectric thin films are mostly lead-containing films. It is well known that heavy metal lead is not friendly to the environment and life, so people have been looking for lead-free ferroelectric materials in the past ten years. In this context, a series of researches on lead-free ferroelectric thin films-barium titanate thin films will be carried out in this thesis. Barium titanate film has excellent ferroelectric, piezoelectric and optoelectronic properties. In the study of ferroelectric properties, barium titanate thin films are usually deposited on silicon substrate with metal bottom electrodes, the thickness of which is more than 100 nanometers, and the investigation on the growth and performance of barium titanate films on the scale of ten nanometers is less than that on the scale of 10 nanometers. In this paper, barium titanate thin films with thickness of several dozen nanometers were deposited on monocrystalline silicon substrates by pulsed electron beam deposition. The surface morphology and composition of barium titanate thin films were investigated by various technological parameters. The influence of structural characteristics and ferroelectric properties. The main research work and achievements are as follows: barium titanate thin films with thickness of several tens nanometers were prepared by pulsed electron beam deposition and their ferroelectric properties were studied. The morphology of barium titanate film was characterized by scanning electron microscope (SEM) and atomic force microscope (AFM). The microdomain was observed by using a voltage power microscope. By comparing the process parameters, we found that the 27.6 nm thick barium titanate thin films deposited at 700 鈩,
本文编号:2407800
[Abstract]:With the continuous development of microelectronic integrated circuits and the development of optoelectronic devices and sensors to micro and nano scale, ferroelectric thin films are widely used in functional devices because of their special ferroelectric properties, and provide more control mechanisms and functional applications. As a result, it attracted wide attention. At present, the widely used ferroelectric thin films are mostly lead-containing films. It is well known that heavy metal lead is not friendly to the environment and life, so people have been looking for lead-free ferroelectric materials in the past ten years. In this context, a series of researches on lead-free ferroelectric thin films-barium titanate thin films will be carried out in this thesis. Barium titanate film has excellent ferroelectric, piezoelectric and optoelectronic properties. In the study of ferroelectric properties, barium titanate thin films are usually deposited on silicon substrate with metal bottom electrodes, the thickness of which is more than 100 nanometers, and the investigation on the growth and performance of barium titanate films on the scale of ten nanometers is less than that on the scale of 10 nanometers. In this paper, barium titanate thin films with thickness of several dozen nanometers were deposited on monocrystalline silicon substrates by pulsed electron beam deposition. The surface morphology and composition of barium titanate thin films were investigated by various technological parameters. The influence of structural characteristics and ferroelectric properties. The main research work and achievements are as follows: barium titanate thin films with thickness of several tens nanometers were prepared by pulsed electron beam deposition and their ferroelectric properties were studied. The morphology of barium titanate film was characterized by scanning electron microscope (SEM) and atomic force microscope (AFM). The microdomain was observed by using a voltage power microscope. By comparing the process parameters, we found that the 27.6 nm thick barium titanate thin films deposited at 700 鈩,
本文编号:2407800
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