论文标题
使用光学表征的硅氧硝基折射率折射率检索的精度
Precision of silicon oxynitride refractive-index profile retrieval using optical characterization
论文作者
论文摘要
具有梯度折射率轮廓的层是传统均匀堆栈涂料的有吸引力的替代品。但是，对分级折射率轮廓的光学表征和监测是一个复杂的问题，通常通过使用简化的混合材料模型来解决该问题。尽管这种方法为问题提供了解决方案，但是从折射率梯度的光学表征可以预期的精度仍不清楚。在这项工作中，我们研究通过反应性双离子束溅射沉积的SIO_XN_Y层的光学表征。为了表征沉积的层，我们使用多种方法，包括反射率和透射光谱，并在各种入射角以及光谱椭圆法。所有数据同时拟合了折射率的一般概况。我们拟合中使用的预期配置文件是基于具有不同化学计量的SiO_xn_y层的表征。通过更改轮廓，我们讨论了这种交替对拟合质量的敏感性，并研究了功绩功能最小化的歧义。我们证明，虽然对轮廓的特定参数的扫描似乎非常精确，但对于广泛的梯度形状的实验数据和模型之间，我们获得了非常良好的一致性，在各种梯度形状中，该轮廓的主要部分的折射率值可能与平均值不同。
Layers with gradient refractive-index profile are an attractive alternative to conventional homogeneous stack coatings. However, the optical characterization and monitoring of the graded refractive-index profile is a complex issue, which has been typically solved by using a simplified model of mixed materials. Although this approach provides a solution to the problem, the precision, which can be expected from optical characterization of the refractive index gradient, remains unclear. In this work, we study optical characterization of SiO_xN_y layers deposited via reactive dual ion beam sputtering. To characterize the deposited layers, we use several methods including reflectance, and transmittance spectra at a broad range of incident angles, together with spectral ellipsometry. All the data were simultaneously fitted with a general profile of refractive index. The expected profile used in our fit was based on characterization of SiO_xN_y layers with a varying stoichiometry. By altering of the profile, we discussed sensitivity of such alternation on fit quality and we studied ambiguity of merit-function minimization. We demonstrate that while the scanning of particular parameters of the profile can be seemingly very precise, we obtain a very good agreement between the experimental data and model for a broad range of gradient shapes, where the refractive-index value on major part of the profile can differ as much as 0.02 from the mean value.
