Ultrasonic Microspectroscopy of LiTaO_3 Single Crystals for Optoelectronic Devices

光电器件用LiTaO_3单晶的超声显微光谱

基本信息

批准号：
07555408
负责人：
KUSHIBIKI Jun-ichi
金额：
$ 3.14万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555408/
关键词：
Ultrasonic microspectroscopy Line-focus-beam acoustic microscopy V (z) curve analysis Leaky surfase acoustic wave velocity Electronic materials Optoelectronic materials LiTaO_3 Material characterzation V (z)曲線解析法

项目摘要

Ultrasonic microspectroscopy technology, especially using the line-focus-beam (LFB) acoustic microscopy system, is very useful and unique for quantitative material characterization by measuring the velocity of leaky surface acoustic waves (LSAWs) , excited on the water-loaded specimen, through V (z) curve analysis. This system has been applied to material problems in the scientific and industrial fields of LiTaO_3 crystals for establishment of the crystal growth conditions and for evaluation of the optoelectronic device fabrication processes such as proton-exchanged and domain-inversion layrs.1.The reliable LFB system with high measurement accuracy in LSAW velocity has been established, resulting in the absolute accuracy within(]SY.+-。[)0.01% and the relative accuracy within(]SY.+-。[)0.001%.2.Three LiTaO_3 crystals of 3-inch-diameter, grown with the different compositions of the starting materials of 48,48.5,49 Li_2O-mol%, have been employed for velocity measurements. It has been shown … More that the velocities on the three basic crystal surfaces of X-, Y-, and Z-cut planes increase for all the surfaces and all the propagation directions monotonically as the Li_2O concentration increases, and the corresponding density decrease monotonically.3.The measured LSAW velocities have been compared with the measured, Curie temperatures, chemical composition, and densities. It has been shown that the LFB system has a much greater sensitivity and resolution in the determination of chemical composition than any other conventional methods such as differential thermal analysis (DTA) , X-ray fluorescence anlysis (XRF) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) .4.Acoustic homogeneity of an optical-grade congruent LiTaO_3 single crystal with 4-inch diameter has been evaluated by LSAW velocity distributions. The velocities have increased by 0.45 m/s, corresponding to the chemical composition change of +0.015 Li_2O-mol%, along the crystal length of 60mm.5.The system has been applied to characterization of proton-exchanged and domain-inverted layrs fabricated on Z-cut LiTaO_3 substrates. It has been demonstrated that the system has the capability to resolve the change of diffusion depth of 1 nm for the proton-exchanged layr and the change of the domain-inverted layr thickness of 1 nm.6.The computer program of numerical calculations of the LSAW propagation characteristics for the layred structures described above has been developed. Less

超声波显微光谱技术，特别是使用线聚焦束 (LFB) 声学显微镜系统，通过测量在含水样品上激发的泄漏表面声波 (LSAW) 的速度，对于定量材料表征非常有用且独特。 V(z)曲线分析已应用于LiTaO_3晶体科学和工业领域的材料问题，用于建立晶体生长条件和评估光电器件制造工艺，例如1、建立了LSAW速度测量精度高、可靠的LFB系统，绝对精度在(]SY.+-.[)0.01%以内，相对精度在( ]SY.+-.[)0.001%.2.三个3英寸直径的LiTaO_3晶体，用48、48.5、49的不同成分生长而成Li_2O-mol% 已用于速度测量，结果表明，X、Y 和 Z 切割面的三个基本晶体表面上的速度在所有表面和所有传播方向上单调增加。随着Li_2O浓度的增加，相应的密度单调减小。3.将测量的LSAW速度与测量的居里温度、化学成分和密度进行了比较。系统在化学成分测定方面比任何其他传统方法（例如差热分析（DTA）、X射线荧光分析（XRF）和电感耦合等离子体原子发射光谱法（ICP-AES））具有更高的灵敏度和分辨率。 4.通过LSAW速度分布评估了直径为4英寸的光学级同质LiTaO_3单晶的声学均匀性，速度增加了0.45 m/s，对应于+0.015 Li_2O-mol%的化学成分变化，沿60mm的晶体长度。5.该系统已应用于Z切割LiTaO_3衬底上制造的质子交换层和畴反转层的表征。系统能够分辨质子交换层扩散深度1 nm的变化和畴反转层厚度1的变化nm.6. 已开发出上述铺设结构的 LSAW 传播特性的数值计算计算机程序。