膜厚对Sb_2Te_3薄膜光学性质的影响  

Dependence of Optical Properties on Thickness of Sb_2Te_3 Film

作　　者：张奎[1] 耿永友[1] 吴谊群[1] 顿爱欢[1] 李豪[1] 

机构地区：[1]中国科学院上海光学精密机械研究所高密度光存储实验室,上海201800

出　　处：《光学学报》2011年第12期299-303,共5页Acta Optica Sinica

基　　金：国家973计划(2007CB935402);国家自然科学基金(50872139);中国科学院院地合作项目资助课题

摘　　要：超分辨近场结构光存储技术(Super-RENS)是一种利用功能薄膜结构实现突破光学衍射极限的信息点记录和读取的新技术,作为超分辨光盘结构的掩膜材料是决定其性能的关键。利用透射电子显微镜研究了可作为超分辨光盘掩膜层Sb2Te3薄膜的晶态结构、表面形貌;利用光谱仪和椭偏仪分析了其光学性质随膜厚的变化。结果表明,沉积态Sb2Te3薄膜呈弱晶状态,在一定厚度范围内,其光学性质随膜厚的不同有较大变化。当膜较薄时,其消光系数和折射率随膜厚的增加而减小;当膜厚达到一定值时,其光学常数随膜厚的增加逐渐趋于稳定,即存在膜厚影响临界值。消光系数和折射率的膜厚影响临界值分别在80nm和50nm左右。薄膜的光学性质与膜厚的关系可以用薄膜结构的连续性来解释。Super-resolution nea-field structure （super-RENS） is one new optical storage technique which can overcome the optical diffraction limit to write and read the recording pits by a functional thin film structure. In general, the performance of super-RENS is mainly determined by the mask material. The microstructure and morphology of the as-deposited Sb2Te3 film are observed by transmission electron microscope （TEM）. The dependences of optical properties on thickness of the Sb2Te3 films are carried out by ellipsometer and optical spectrometer, respectively. The results indicate that the as-deposited Sb2Te3 film is partly crystallized. Moreover, the optical properties change a lot within a certain thickness range. The extinction coefficient and refractivity of Sb2Te3 film decrease with the increase of thickness when the thickness is very small. Moreover, the optical constants tend to be stable when the thickness reaches a critical value. This critical value is 80 nm for the extinction coefficient, and 50 nm for refractivity of the film. The relationship betwean the optical property and thickness of Sb2Te3 film can be explained by the continuity of film structure.

关 键 词：薄膜 超分辨近场结构 Sb2Te3薄膜 光学性质 膜厚 临界值 

分 类 号：TN248.1[电子电信—物理电子学]