相变光盘溅射靶材和Ge-Sb-Te-O薄膜的制备和性能研究
文献类型：学位论文
| 作者 | 顾四朋 |
| 学位类别 | 硕士 |
| 答辩日期 | 2002 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 侯立松 |
| 关键词 | 光存储 相变光盘 靶材 Ge-Sb-Te-O薄膜 光学常数 动态存储性能 |
| 其他题名 | Preparation and properties of sputtering targets and Ge-Sb-Te-0 films for optical storage |
| 中文摘要 | 该文对磁控溅射制备的氧掺杂Ge-Sb-Te薄膜的结构、光学及光存储性能进行了系统研究.对相变光盘溅射用靶材的粉末冶金工艺进行了全面的研究,制备了φ100mm靶材.通过对整个工艺过程中各元素的百分含量的分析测定,对稳定靶材的设计成分具有指导意义.对烧结样品的横截面上不同微区的成份进行了测定,发现各元素在靶材中的分布是均匀的.起初靶材密度较低的原因主要是由于冷等静压力过低和氧化造成的.通过优化冷等静压力,样品的密度已经非常接近其设计密度.测定各个工艺阶段的氧成分,发现样品的氧化主要在球磨阶段,加强防氧化保护十分重要.以Ge-Sb-Te合金靶采用磁控溅射方法在不同的氧分压下制备了Ge-Sb-Te-O薄膜.对薄膜的光谱及光学常数的研究表明,不同氧含量的Ge-Sb-Te-O薄膜,其反射率(R)随着氧含量的增加而减少,透过率(T)随着氧含量的增加而增大,特别是在长波长变化更为明显.样品的折射率和消光系数随着氧含量的增大都相应地减小.在氩气保护下275℃热处理30分钟后,薄膜光学常数有很大的变化.在400~585nm波长之间氧掺杂量为4.132at.%时样品的消光系数最大.使用测定得到的n,k数据计算出了薄膜的晶态和非晶态反射率,发现结果和实际测出的薄膜反射率具有很好的一致性,证明了实验结果的正确.利用X射线衍射分析对热处理前后薄膜的结构变化进行了测定.发现各种氧含量的薄膜在真空热处理后都有明显的衍射峰,表明经过热处理后薄膜发生了非晶态到晶态的相变. |
| 英文摘要 | With the advent of the multimedia era, the demand for high speed and high-density optical recording media is becoming higher and higher. Optical disk storage is a new information processing technology developed in the 1970s'. Now, there are two main objectives in the optical disk storage technology. One is to improve the recording density, and the other is to improve the data transfer rate. In optical disk storage, development of recording media is most essential. Some new optical storage technologies appeared only with the development of novel recording materials. Phase change materials have been developed for erasable data storage, such as CD-RW and DVD-RAM. Typically, the recording layer is a kind of Te-based alloys such as GeSbTe and AglnSbTe, which have been attracting much attention. In this thesis, we address the issue of improving the performance of the recording materials. In the study on the optical disc storage materials, the power metallurgy technology for preparing sputtering targets of Ge-Sb-Te and Ag-In-Sb-Te is investigated and a systemic study on the structural, optical and recording properties of the Ge-Sb-Te-O thin films is also presented. The powder metallurgy technology for sputtering targets for phase change disc was studied. Good targets of 0100mm have been prepared. For determining the composition of the targets, we analyzed their elemental contents, which has important meaning for target design and preparation. The composition of different micro-zone in the cross section of sintered samples was analyzed. We found that the distribution of each element in the target was very even. The lower initial density of the targets resented from lower cold pressure force and oxidation. By increasing the cold pressure force, the density of the targets could be raised close to the density of the standard one. Through the chemical analysis of oxygen content of the targets, we found that the oxidation was obvious, therefore protection by inertia gas is very important. Ge-Sb-Te-0 thin films were deposited by reactive RF-sputtering using Ge-Sb-Te alloy target in a mixture of argon-oxygen plasma with different ratio of oxygen to argon. The reflection and transmission spectra and optical constants (n,k) of the films were studied. With increasing oxygen content, the reflection decreases and the transmission increases; while with the refractive index (n) and extinction coefficient (k) decrease monotonically . After annealing at 275 ℃ under protection of argon for 30 minutes, the optical constants(n,k) of the films changed considerably. The extinction coefficient of the films with 4.132at% oxygen is the highest in the 400-585nm region. Theoretically calculated reflections agree well with the measured results. The XRD analyses indicated that phase change from amorphous to crystallitic took place. For practical applications, a rewritable material should possess a high signal-to-noise ratio (CNR). This can be translated into a high reflectivity contrast(C) before and after writing or erasing. The reflectivity contrast of the film containing 4.132at% oxygen is as high as 35% at 500nm, but that it decreases with increasing oxygen content. This indicates that proper oxygen-doping can improve the recording performance of the Ge-Sb-Te film. The dynamic optical recording performance of the discs using Ge-Sb-Te-0 and Ge-Sb-Te as the recording materials was measured and compared. The disc using Ge-Sb-Te-0 containing 4.132% oxygen possesses a CNR of 42dB at 780nm with a initialization power of 1300mW, initialization speed of 3.6m/s, writing power of 13.5mW and writing pulse width of 500ns. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16484]  |
| 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 | 顾四朋. 相变光盘溅射靶材和Ge-Sb-Te-O薄膜的制备和性能研究[D]. 中国科学院上海光学精密机械研究所. 2002. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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