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在衬底加热条件下利用磁控溅射法制备Ge2Sb2Te5薄膜,利用X射线衍射仪表征各种沉积温度下薄膜的结构,差示扫描量热法(DSC)确定的薄膜晶化温度为168℃(加热升温速率为5℃/min)。用四探针法测试薄膜的方块电阻,分光光度计测试薄膜的反射率谱,并根据反射率数据讨论在波长为405和650nm时薄膜的反射率对比度同沉积温度关系。结果表明:室温沉积的薄膜为非晶态;在衬底温度为140℃条件下薄膜已完全转变为晶态Ge2Sb2Te5,在300℃时出现少量的六方相;低于140℃时易形成非Ge2Sb2Te5组分的其它晶相,它们对薄膜的电/光性质有很大的影响,可能是导致此类相变光存储薄膜使用过程中反射率对比度下降的原因。
Ge2Sb2Te5 thin films were prepared by magnetron sputtering under the substrate heating conditions. The structure of the films was characterized by X-ray diffractometry at various deposition temperatures. The film crystallization temperature determined by differential scanning calorimetry (DSC) was 168 ℃ Heated heating rate of 5 ℃ / min). The square resistance of the film was measured by the four-probe method. The reflectance spectrum of the film was measured by a spectrophotometer. The relationship between the contrast of the film and the deposition temperature at 405 and 650 nm was discussed based on the reflectance data. The results show that the film deposited at room temperature is amorphous, the film has completely transformed into crystalline Ge2Sb2Te5 at 140 ℃, and a small amount of hexagonal phase occurs at 300 ℃. When the temperature is below 140 ℃, the non-Ge2Sb2Te5 The other crystalline phases, which have a great influence on the electrical / optical properties of the films, may be responsible for the degradation of the contrast ratio of reflectivity during the use of such phase-change optical storage films.