【作者】 都健；

【导师】 张庆瑜；

【作者基本信息】 大连理工大学 ， 材料物理与化学， 2006， 硕士

【摘要】 光盘存储技术在信息社会中发挥着越来越重要的作用，但其它数据存储技术的飞速发展使传统光盘数据存储技术面临挑战，信息技术的发展急需开发更高存储密度的光存储系统。目前光存储朝着高密度、大容量、高数据传输速率、多功能方向发展，相变光盘存储材料的优劣是影响相变光存储的关键，研究和开发性能优良的相变材料一直是发展相变光盘的核心。 本文采用射频磁控溅射方法在n-Si（100）、石英玻璃基片上外延生长Ge₂Sb₂Te₅相变存储薄膜，对薄膜的热力学性能、表面形貌、组织结构、光学特性进行了系统的检测与分析；讨论了沉积温度、工作气压等参数对薄膜结构性能的影响。本论文主要研究结果如下： 1．采用射频磁控溅射方法，在石英玻璃基片上制备了Ge₂Sb₂Te₅相变薄膜。X射线衍射分析表明：室温沉积的薄膜为非晶态；170℃真空退火后，薄膜转变为晶粒尺度约为17nm的面心立方结构；250℃退火导致晶粒尺度约为40nm的密排六方相的出现。差热分析显示：薄膜的非晶相向fcc相转变的相变活化能为2.03±0.15eV；fcc相向hex相转变的相变活化能为1.58±0.24eV。薄膜反射率测量表明：面心相与非晶相的反射率对比度随着波长的增加在15～30％之间变化，六方相与非晶相的反射率对比度在30～40％之间。不同脉冲宽度的激光对非晶态薄膜的辐照结果显示：激光的能量密度对薄膜的记录效果有显著影响，在5mW、50ns的脉冲激光作用下，Ge₂Sb₂Te₅薄膜具有最好的光存储效果。 2．通过优化实验工艺和调整实验参数，分别在玻璃基片和具有本征氧化层的Si（100）基片上制备了Ge₂Sb₂Te₅相变薄膜。利用X射线衍射、扫描电子显微镜（SEM）、原子力显微镜（AFM）、紫外分光光度计等分析方法对薄膜进行了系统表征，研究了不同生长温度（室温～300℃）下Ge₂Sb₂Te₅薄膜的表面形貌和结晶特性。分析结果表明：沉积的薄膜生长质量良好，晶粒匀化、细小。室温沉积的薄膜为非晶态；沉积温度为100～250℃时，薄膜转变为晶粒尺度约为14nm的面心立方结构；300～350℃沉积的薄膜有少量的六方相的出现。薄膜表面粗糙度随着沉积温度的升高逐渐递增，且薄膜的反射率变化与表面粗糙度有直接的关系。 3．优化镀膜工艺制备Ge₂Sb₂Te₅相变薄膜，分别在0.2、0.5、0.8、1.2和2.0Pa的溅射气压下制备了非晶态的相变薄膜；通过原子力（AFM）表征在不同溅射气压下，制备的Ge₂Sb₂Te₅薄膜达到了原子级平滑，粗糙度均小于1nm，这对制备高性能的相变光盘是十分有利的。更多还原

【Abstract】 Optical data storage techniques are playing a more and more important role in modern information society, but the traditional optical disc storage techniques is facing the challenge not only from the rapid development of other data storage techniques, but also from the demands of new optical disk storage products with higher storage density and capacity. Optical storage is developing towards high density, large capacity, high data transfer rate and multifunctional usage. Among the others, phase-change materials and technology have been art racting more and more interest because of their successful application in rewritable optical storage.In this study, Ge₂Sb₂Te₅ thin films have been deposited on n-Si （100） and quartz substrates by radio frequency magnetron sputtering. The influence of substrate temperture and sputtering pressure is emphasized. The morphological and structural chacterizations have been carried out using atomic force microsiscopy, transmission electron microscopy, x-ray diffraction. The major points of this thesis are summarized as follows:1. Using a radio-frequency magnetron sputtering method, Ge₂Sb₂Te₅ films were grown on quartz substrates at room temperature. X-ray diffraction analysis revealed the as-deposited films to be amorphous. The films have a face-center-cubic （fcc） structure with the grain size of 17 nm and hexagonal （hex） structure with the grain size of 40 nm after annealed at 170°C and 250°C in a vacuum chamber, respectively. The thermodynamics behavior of the phase transition of the films was studied in the temperature ranging from room temperature to 450°C. It was found the activation energy of phase transition to be 2.03±0.15eV from amorphous to fcc phase and 1.58±0.24eV from fcc phase to hex phase. The reflection contrast increases from 15 to 30% for fcc films and from 30 to 40% for hex films with increasing the wavelength from 400 to 1000 nm. Under the irradiation of a 5 mW pulsed laser at a wavelength of 650 nm, the influence of pulse width on the phase transition was studied for the laser pulse durations of 40, 50, 75,100, 400, and 1000 ns.2. Ge₂Sb₂Te₅ thin films have been deposited on glass substrates and Si（ 100） substrates with a native oxide layer. The structures and morphologies of the films have been determined by using X-ray diffraction, scanning electron microscopy, atomic force microscopy and ultraviolet spectrometer. The films were deposited at the substrates temperatures of room更多还原