亚波长浮雕结构的红外抗反射研究

BINARY SUBWAVELENGTH RELIEF STRUCTURES FOR INFRARED ANTIREFLECTION

基于等效媒质理论 ,对周期性浮雕结构的抗反射特性进行了分析和研究 .给出了二维对称的抗反射浮雕结构等效光学参数的估算方法 .提出了基于最小特征尺寸考虑的脊基和隙空的设计概念 .利用离子束刻蚀工艺技术 ,在 Si片上制备了一种两维红外抗反射浮雕图案 .测试结果表明 ,这种表面结构像单层抗反射膜一样 ,具有很好的增透效果 ,表面结构的等效折射率相当于镀层材料折射率 ,而刻蚀深度则相当于镀层的 1/ 4波长厚度 .

Based on the effective medium theory, the antireflection properties of periodic subwavelength surface relief structures were analyzed and investigated. An estimation method for effective optical index for 2 D symmetric structures was given. Based on the consideration of feature size, the design concept of ridges and meshes was suggested. A two dimensional infrared antireflection relief pattern was fabricated on a Si wafer, using ion beam etching process. From experimental results, it was shown that the structures, of which the characteristics are similar to that of a single antireflection film, obviously suppressed the reflection in infrared spectrum, and its effective refractive index is equivalent to the refractive index of the film. And the etching depth is equivalent to the thickness of 1/4 wavelength of the film.