【摘要】：隨著微電子集成電路的不斷發(fā)展,光電子器件和傳感器向微納尺度發(fā)展,鐵電薄膜因其特殊的鐵電性能而在功能器件中得以廣泛應用,并且提供了更多的調控機制和功能應用,因而吸引了廣泛的關注。目前,廣泛使用的鐵電薄膜多為含鉛薄膜,眾所周知,重金屬鉛對環(huán)境和生命體不友好,因此人們在過去十年時間里一直致力于尋找無鉛鐵電材料。在這樣的背景下,本論文將針對“無鉛”鐵電薄膜—鈦酸鋇薄膜展開一系列的研究探索。鈦酸鋇薄膜具有優(yōu)異的鐵電性能、壓電性能以及光電性能。在探究其鐵電性能時,鈦酸鋇薄膜通常被沉積在具有金屬底電極的硅基底上,厚度多在百納米級別以上,在十納米尺度生長及性能研究方面的探究比較少。本論文使用脈沖電子束沉積技術在單晶硅基底上制備厚度為幾十納米的鈦酸鋇薄膜,探究其各項工藝參數(shù)對鈦酸鋇薄膜的表面形貌、組成成分、結構特性以及鐵電性能等的影響。論文主要的研究工作和成果有:利用脈沖電子束沉積技術制備了厚度為幾十納米的鈦酸鋇薄膜,對其進行了材料表征并研究其鐵電性能。用掃描電子顯微鏡以及原子力顯微鏡對其形貌進行表征可以發(fā)現(xiàn)鈦酸鋇薄膜表面較為平整均勻;用X射線衍射圖譜分析其結晶取向性較好;用壓電力顯微鏡觀察其具有微觀電疇。通過比較各工藝參數(shù),我們發(fā)現(xiàn)當沉積時基底溫度為700℃,在單晶硅基底上制備出的27.6 nm厚的鈦酸鋇薄膜具有非常好的宏觀以及微觀的鐵電性能。當其厚度不斷增加時,其宏觀鐵電性能被優(yōu)化,薄膜內部的微觀電疇更被易外加電場調控。本論文進一步研究了鈦酸鋇薄膜非原位熱處理工藝對其各性能的影響。將使用脈沖電子束沉積技術制備好的鈦酸鋇薄膜在空氣中長時間退火后發(fā)現(xiàn),該熱處理工藝可以改善鈦酸鋇薄膜中缺氧的狀態(tài),其結晶取向性增強,微觀電疇的體積也有顯著增大,而且其宏觀鐵電性能也有顯著提高。
[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，

本文編號：2407800