Development of a Raman spectrometric system and application to characterization of ultra thin films of atomic scale

拉曼光谱系统的开发及其在原子级超薄膜表征中的应用

• 批准号: 04555005
• 负责人: NAKASHIMA Shin-ichi
• 金额: $ 6.78万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-04555005/
• 关键词: Raman scattering; ultra-thin films; weak-signal detection; ZnTe films; silicon films; GaSb films; SiC films; マルチチャネル検出器; ノッチフィルター; ZnTe; ZnSe; GaSb; GaAs

The aim of this project is (1) to construct a system for Raman spectroscopy which provides us with high through-put and excellent rejection rate for Rayleigh light and (2) to apply the constructed system to characterization of ultra thin films of semiconductors and also materials with very small scattering efficiency. Our system consists of a notch filter and a double monochromator with high reflection mirrors.The through-put of the double monochromator is 24%, which greatly exceeds those of conventional systems. The detection limit of weak Raman signals has been evaluated actually. It was about 2cps (counts per second) when using a photomultiplier and 0.1 cps for a CCD detector.Using the constructed system we have characterized thin epitaxial films of semiconductors and silicon on insulators. Furthermore, phase transition of C_<60> crystals and electronic Raman scattering of doped SiC crystals have been studied.We could measure the Raman spectra of ZnTe and GaSb films with thicknesses down to 2nm. Residual stress and quality of the films have been characterized from the thickness dependence of the Raman spectra.The crystallinity of GaAs films grown at low temperatures has also been evaluated.Conversion from amorphous state to crystalline state by thermal annealing has been studied by measuring the two-dimensional Raman image of silicon on insulator (SOI) structures.Our system has enabled us to measure the Raman spectra of C_<60> crystals at lower laser powers below a critical power producing photo-induced structural change.

本项目的目的是（1）构建一个拉曼光谱系统，该系统为我们提供高吞吐量和优异的瑞利光抑制率，（2）将构建的系统应用于半导体超薄膜和具有非常小的散射效率的材料的表征。我们的系统由陷波滤波器和高反射镜双单色器组成，双单色器的吞吐量为24%，大大超过了常规系统。对微弱拉曼信号的检出限进行了实际评价。用光电倍增管时的计数率约为2cps，用CCD探测器时的计数率约为0.1cps。在此基础上，研究了C_2晶体的相变<60>和掺杂SiC晶体的电子拉曼散射，测量了ZnTe和GaSb薄膜的拉曼光谱，厚度可达2nm。用拉曼谱表征了薄膜的残余应力和质量，评价了低温下生长的GaAs薄膜的结晶性。通过测量绝缘体上硅（SOI）结构的二维拉曼像，研究了热退火过程中非晶态到晶态的转变。我们的系统使我们能够<60>在低于产生光致结构变化的临界功率的较低激光功率下测量C_（10）晶体的拉曼谱。

项目成果

中島 信一: "Characterization of Ion Implantation Dose by Raman Scattering and Photothermal Wave Techniques" Jpn.J.Appl.Phys.31. L1422-1424 (1992)

Shinichi Nakajima：“通过拉曼散射和光热波技术表征离子注入剂量”Jpn.J.Appl.Phys.31 (1992)。

M.Hangyo, S.Nakashima, Y.Hamada, T.Nishio and Y.Ohno: "Raman scattering from the misfit-layr compounds SnNbS_3, PbNbS_3, and PbTiS_3." Phys.Rev.B. vol.48. 11291-11297 (1993)

M.Hangyo、S.Nakashima、Y.Hamada、T.Nishio 和 Y.Ohno：“错配层化合物 SnNbS_3、PbNbS_3 和 PbTiS_3 的拉曼散射。”

中島信一: "Temperature Dependence of the Electronic Raman Spectra of Bi_2Sr_2CaCu_2O_8 above T_C" Physical Review B. 47. 14595-14598 (1993)

Shinichi Nakajima：“T_C 以上 Bi_2Sr_2CaCu_2O_8 电子拉曼光谱的温度依赖性”物理评论 B. 47. 14595-14598 (1993)

S.Nakashima, K.Kisoda and J.-P.Gauthier: "Raman determination of structures of long-period SiC polytypes." J.Appl.Phys.vol.75. 1-7 (1994)

S.Nakashima、K.Kisoda 和 J.-P.Gauthier：“长周期 SiC 多型体结构的拉曼测定”。

中島信一: "Raman Scattering from the Misfit-layer Compounds SnNbS_3,PbNbS_3 and PbTiS_3" Physical Review B. 48. 11291-11297 (1993)

Shinichi Nakajima：“错位层化合物 SnNbS_3、PbNbS_3 和 PbTiS_3 的拉曼散射”物理评论 B.48.11291-11297 (1993)