利用光谱椭偏测量法表征CaCu3Ti4O12薄膜的最新进展。

Recent advances in characterization of CaCu3Ti4O12 thin films by spectroscopic ellipsometric metrology.

作者信息

Lo Nigro Raffaella, Malandrino Graziella, Toro Roberta G, Losurdo Maria, Bruno Giovanni, Fragalà Ignazio L

机构信息

Istituto per la Microelettonica e Microsistemi, IMM-CNR Stradale Primosole 50, 95121 Catania, Italy.

出版信息

J Am Chem Soc. 2005 Oct 12;127(40):13772-3. doi: 10.1021/ja0541229.

DOI:10.1021/ja0541229

PMID:16201781

Abstract

CaCu3Ti4O12 (CCTO) thin films were successfully grown on LaAlO3(100) and Pt/TiO2/SiO2/Si(100) substrates by a novel MOCVD approach. Epitaxial CCTO(001) thin films have been obtained on LaAlO3(100) substrates, while polycrystalline CCTO films have been grown on Pt/TiO2/SiO2/Si(100) substrates. Surface morphology and grain size of the different nanostructured deposited films were examined by AFM, and spectroscopic ellipsometry has been used to investigate the electronic part of the dielectric constant (epsilon2). Looking at the epsilon2 curves, it can be seen that by increasing the film structural order, a greater dielectric response has been obtained. The measured dielectric properties accounted for the ratio between grain volumes and grain boundary areas, which is very different in the different structured films.

摘要

通过一种新颖的金属有机化学气相沉积（MOCVD）方法，成功地在LaAlO3(100)和Pt/TiO2/SiO2/Si(100)衬底上生长了CaCu3Ti4O12（CCTO）薄膜。在LaAlO3(100)衬底上获得了外延CCTO(001)薄膜，而在Pt/TiO2/SiO2/Si(100)衬底上生长了多晶CCTO薄膜。通过原子力显微镜（AFM）检查了不同纳米结构沉积薄膜的表面形貌和晶粒尺寸，并使用光谱椭偏仪研究了介电常数的电子部分（ε2）。从ε2曲线可以看出，随着薄膜结构有序度的增加，获得了更大的介电响应。所测量的介电性能说明了晶粒体积与晶界面积之比，这在不同结构的薄膜中差异很大。