雷射干涉重力波天文台利用大型麥克森干涉儀探測重力波訊號。重力波訊號非常微弱不易偵測，因此需降低偵測時的雜訊，方可探測到更大量的重力波訊號；其中高反射鏡之薄膜熱雜訊是主要雜訊之一，此雜訊會與材料之機械損耗成正比關係。此外高反射鏡材料的光學特性也需有一定的品質，因此本研究致力開發低機械損耗且具良好光學特性之材料。
本實驗室所開發之高氮氮化矽薄膜在室溫下有良好之機械損耗，但有較高的光學吸收，在低溫下機械損耗也偏高，並未達到下世代的Voyager重力波探測站的規格需求；本研究藉由高溫熱退火製程，設法降低高氮氮化矽薄膜的機械損耗與光學吸收，並量測分析退火後材料的應力、楊氏模數、鍵結密度、光學特性以及室溫與低溫機械損耗。
光學特性量測結果發現N-H鍵以及光學吸收都會因為退火溫度提升而有下降的趨勢，兩者下降的幅度呈現線性正相關。低溫機械損耗量測結果發現退火900℃後N-H鍵的下降使材料中N-H鍵多種穩態的轉換減少，因此大幅降低低溫下的機械損耗；在20K溫度下仍有一較小之損耗峰值，此損耗峰值之活化能大小約為44.9meV；在120K溫度下有極低的機械損耗大小約為3.4×10^(-5)，此損耗大小符合下世代Voyager重力波探測站的高反射鏡的規格。

The Laser Interferometer Gravitational-wave Observatory detect the cosmic gravitational waves by using large Michelson interferometer. The gravitational waves signals are very weak and hard to detect, so it is necessary to reduce the noises of the detector to detect more gravitational waves signals. The coating Brownian noise is one of the main noises and it is proportional to the mechanical loss. In addition, coating materials must have high-quality optical properties. Therefore this thesis is dedicated to developing the material with low mechanical loss and low optical loss.
In our group have developed the nitrogen-rich silicon nitride. The properties of this material have the low mechanical loss at room temperature but have high optical absorption and high cryogenic mechanical loss. These hinder the application of the coating to the next-generation detector. In this research, we try to use thermal annealing to reduce its optical loss and mechanical loss. Further, we measure and analyze its stress, Young’s modulus, bond concentrations, optical properties, and mechanical loss to find the way to achieve the specification of the next-generation detector.
The experimental results show that the N-H bond concentration and optical absorption will decrease by increasing the annealing temperature, and the magnitude of the decrease is linearly positively correlated. The cryogenic mechanical loss of the film is extremely reduced after annealing at 900℃ because of the decrease of the two-level system associated with the N-H bond. The cryogenic loss peak is at approximately 20K. The activation energy of these loss peaks is about 44.9meV. At 120K, the loss value is about 3.4×10^(-5) that is a potential candidate material in the next-generation cryogenic detector.

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