| 题名 | 相变薄膜光学性质与光电混合存储特性研究 |
| 作者 | 翟凤潇 |
| 学位类别 | 博士 |
| 答辩日期 | 2010 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 干福熹 ; 王阳 |
| 关键词 | 信息存储 相变薄膜 光/电性质 光电混合存储 泵浦-探测 |
| 其他题名 | Optical properties and optical-electical hybrid storage characteristics of phase change thin films |
| 中文摘要 | 相变薄膜是可擦重写相变光盘和相变随机存储器的信息存储介质，在超分辨光存储和光电混合存储中也发挥重要作用。对相变薄膜的光学性质和光电混合存储特性的系统研究有助于加深对相变存储机理的理解、可以为优化器件性能和发展新型相变存储器技术提供有益的参考。本文综述了相变存储技术的主要研究进展，对相变存储材料的研究方法进行了详细的介绍。在此基础上，构建了多套用于相变薄膜材料光、电特性测试的实验装置，研究了多种相变薄膜的掩膜开关特性和激光记录-电读出特性，利用泵浦-探测光电特性测试系统实现了原位光电混合相变存储。具体研究内容和结果如下： 1. 设计搭建了多套相变材料测试装置，主要包括：（1）蓝绿光记录测试装置；（2）微区共焦Z扫描测试装置；（3）微区光谱测试装置；（4）泵浦-探测原位光电性质测试装置。实验装置主要用于在不同的激光作用条件下，相变材料的光、电学性质和存储特性的研究，为研究工作的开展提供了前提保障。 2. 利用微区共焦Z扫描技术和泵浦-探测技术研究了BiSb和Sb超分辨掩膜的光热相变性质和光热开关特性。研究表明， BiSb和Sb膜具有稳定重复光热开关特性。测得BiSb和Sb的皮秒激光诱导的相变致开关时间可小于20ns。实验上直观演示了超分辨掩膜晶态（固态）-非晶态（熔化态）转变引起的瞬态光学反射特性变化形成“快速开孔”的过程。研究结果可以为深入理解超分辨掩膜的工作机制和掩膜材料的选择、设计提供重要参考。 3. 利用交叉参数法，通过改变激光的功率、脉宽在Ge1Sb4Te7薄膜上获得了不同纳秒激光脉冲参数条件下的相变记录点阵。通过比较其导电原子力显微镜电流像、光学显微镜像和原子力显微镜形貌像的对比度，直观展示了光电混合相变存储表面形貌变化小、电读出对比度高的特性。 4. 利用皮秒脉冲泵浦、连续光探测的测试技术研究了AgInSbTe薄膜在皮秒激光脉冲作用下的瞬态晶化过程，利用导电原子力显微镜研究了AgInSbTe薄膜沉积态和皮秒激光晶化点的电学性质，皮秒激光晶化微区与非晶态基底之间可以获得约三个数量级的电阻率比。实现了超快激光记录-电读出，展示出光电混合存储激光记录速度快和电学读出对比度高的特性。 5. 利用泵浦-探测光电特性测试系统研究了AgInSbTe相变薄膜在纳秒激光脉冲作用下的时间分辨光学、电学性质演化的动力学过程，实现了原位光电混合相变存储，记录前后电阻率比可达2-3个数量级。原位、同步光电性质演化过程研究有助于更深入认识光电混合存储的机制，通过进一步优化执行机构和材料，可望构建光电混合相变存储原型器件。 |
| 英文摘要 | Phase change thin film is used as the recording medium of rewritable phase-change optical discs and phase-change random access memory, and also plays an important role in the super-resolution optical storage and optical-electrical hybrid storage. To study the optical properties and optical-electrical hybrid storage characteristics of phase change thin films is very helpful to deeply understand the mechanism of phase change storage, optimize the performance of memory devices and develop new phase change storage technology. In this dissertation, current status and development trend of phase change storage technologies, especially the research methods for phase change materials are reviewed and analyzed. Some experimental setups for studying optical/electrical properties of phase change materials are designed and constructed. Switching effect of phase change mask layers and laser-recording/electrical reading properties of phase change thin films are investigated. In situ optical-electrical hybrid data storage is demonstrated by an optical-electrical pump-probe experimental setup. The details are given as follows: 1. Some experimental setups for studying optical/electrical properties of phase change materials are designed and constructed, including: (1) blue-green laser static recoding setup; (2) micro-area confocal Z-scan testing system; (3) micro-area spectroscopy under laser irradiation; and (4) pump-probe system for in situ transient optical/electrical properties testing. These experimental setups can provide main testing platform for the study of optical, electrical and recording properties of phase change material under different laser irradiation parameters. 2. Opto-thermal phase changing and switching effect of BiSb and Sb films are investigated by Z-scan method and pump-probe technology. Experimental results indicate that stable and repeatable optical switching driven by picosecond laser pulses can be achieved on BiSb and Sb thin films. The switching times of BiSb and Sb thin films can be less than 20ns. The fast “pinhole” formation process induced by the transient reflection change between crystalline (solid) and amorphous (molten) states in super-resolution mask layers is time-resolved demonstrated. These results are helpful for the understanding the working mechanism and material selecting of super resolution mask layer. 3. Optical and electrical properties of Ge1Sb4Te7 thin films are investigated by orthogonal pulsed-laser recording test (changing power and pulse duration). Crystallized recording bits arrays were formed under different laser irradiation parameters. The characteristics of little change of topography and lager electrical contrast for optical-electrical hybrid storage are demonstrated by comparison of scanning current image, optical image and AFM image. 4. The phase change dynamics of AgInSbTe thin films are studied by single-shot picosecond laser pulse pumping, CW laser probing system. The electrical properties of nonirradiated and irradiated area by picosecond laser pulse are investigated and compared by C-AFM. The resistivity contrast can be about there orders of magnitude between nonirradiated and irradiated areas. Ultrafast laser-recording/electrical readout is realized. The characteristics of high laser recording speed and lager electrical readout contrast for optical-electrical hybrid storage are demonstrated. 5. The transient change process of optical and electrical properties of AgInSbTe thin films induced by nanosecond signal-shot laser pulses are studied by a pump-probe setup. In situ optical-electrical hybrid storage is realized based on it. The resistivity contrast of 2-3 orders of magnitude can be achieved. The study on real-time and in situ dynamics of optical/electrical properties is helpful to understand the mechanism of optical-electrical hybrid storage. The prototype device of optical-electrical hybrid phase change memory can be expected after optimization of driving units and materials. |
| 语种 | 中文 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15641]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 翟凤潇. 相变薄膜光学性质与光电混合存储特性研究[D]. 中国科学院上海光学精密机械研究所. 2010. |
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