Effect of elevated substrate temperature deposition on the mechanical losses in tantala thin film coatings
Effect of elevated substrate temperature deposition on the mechanical losses in tantala thin film coatings
复制标题
高温沉积对氧化钽薄膜涂层机械损失的影响
DOI：
10.1088/1361-6382/aaad7c
复制
发表时间：
2018
影响因子：
3.5
通讯作者：
Gibson, D
中科院分区：
文献类型：
--
作者：
Vajente, G;Birney, R;Ananyeva, A;Angelova, S;Asselin, R;Baloukas, B;Bassiri, R;Billingsley, G;Fejer, M M;Gibson, D
介质多层膜中的布朗热噪声限制了当前和未来干涉引力波探测器的灵敏度。在这项工作中，我们探索的可能性，提高机械损耗的钽，经常被用作高折射率材料，通过将其沉积在基板上保持在升高的温度。当应用于非晶硅时，以前已经用这种技术获得了有希望的结果。我们发现，在热衬底上沉积钽降低了沉积涂层的机械损失，但随后的热处理有更大的影响，因为它们将损失降低到文献中先前报道的水平。我们还表明，机械损耗的减少与增加中程秩序的原子结构的涂层，使用X-射线衍射和拉曼光谱。最后，讨论包括在我们的研究结果，这表明，纯钽涂层的高温沉积不会出现以类似的方式减少机械损耗，在文献中报道的非晶硅，我们提出了可能的未来研究方向。
Brownian thermal noise in dielectric multilayer coatings limits the sensitivity of current and future interferometric gravitational wave detectors. In this work we explore the possibility of improving the mechanical losses of tantala, often used as the high refractive index material, by depositing it on a substrate held at elevated temperature. Promising results have been previously obtained with this technique when applied to amorphous silicon. We show that depositing tantala on a hot substrate reduced the mechanical losses of the as-deposited coating, but subsequent thermal treatments had a larger impact, as they reduced the losses to levels previously reported in the literature. We also show that the reduction in mechanical loss correlates with increased medium range order in the atomic structure of the coatings using x-ray diffraction and Raman spectroscopy. Finally, a discussion is included on our results, which shows that the elevated temperature deposition of pure tantala coatings does not appear to reduce mechanical loss in a similar way to that reported in the literature for amorphous silicon; and we suggest possible future research directions.