二維材料現在為半導體開發和相關技術開啟了新的方向和可能性。更多的二維材料種類被發現以及製造後，過渡金屬二硫化合物( Transition Metal Dichalcogenide, TMD) 被認為是最有可能應用於積體電路的材料。在經過對於TMD的探索後，我們選擇二硫化鉬 (Molybdenum Disulfide, MoS2) 作為材料，並利用氣相沉積法 ( Chemical Vapor Deposition, CVD ) 生長在有氧化層的矽 ( Silicon, Si ) 基板上，兩層硫原子平面之間夾著一層鉬原子平面，這構成了單層二硫化鉬平面，而在SiO2/Si基板與MoS2單層之間是以微弱的凡德瓦力（Van der Waals）相連，但是MoS2有其區域性在同一塊基板上長的MoS2可能結晶或是發光能力會不一樣。所以我們利用飛秒雷射（Femtosecond Laser）聚焦在同一基板不同區域的MoS2表面或體積上，利用高能量密度的雷射使材料照射區域溫度升高並冷卻使使其重新結晶，進而優化具有缺陷的MoS2。這種方法可以在非常短的時間內完成，因此可以避免材料因長時間在熱效應的影響而引起的其他變化，也因為這個實驗有許多不同的參數可以做調整：可以調整功率的高低進而加工不同傷害閾值的材料；可以控制不同的加工範圍大小進而加工不同尺寸的樣品。本次實驗我們用光致發光（Photoluminescence, PL）及拉曼（Raman）作為檢測系統，在PL檢測過程中會用雷射照射到樣品上，使其電子躍遷到高能態。而當這些電子回到低能態時，會釋放出能量並且產生輻射，從而產生發光現象。然而拉曼的部分是因為拉曼光譜學可以檢測出其中的缺陷。這些缺陷會對應特定的拉曼光譜訊號，因此可以通過對拉曼頻譜進行分析，進而定性和定量分析材料中的缺陷，兩種方法讓我們確認經過雷射退火後的MoS2樣品是否會因為經過雷射退火再結晶後，優化缺陷且加強發光能力。

Two-dimensional materials are now opening up new directions and possibilities for semiconductor development and related technologies. With the discovery and manufacturing of more types of two-dimensional materials, TMD are considered the most promising materials for application in integrated circuits, particularly as channel materials in FET ( Field - Effect Transistor ), due to their well-suited bandgap size.Following exploration of transition metal dichalcogenides, we selected MoS2 as the material. We utilized CVD to grow MoS2 on SiO2/Si substrates. In this process, a monolayer of Mo atoms is sandwiched between two layers of sulfur atoms, forming a monolayer MoS2 plane. The connection between the Si substrate and the monolayer MoS2 is established through weak Van der Waals forces, but MoS2 may exhibit variations in crystallization or luminescence ability within the same substrate region.To address this, we employed femtosecond laser focusing on different regions of the MoS2 surface or volume on the same substrate. By irradiating the material with high-energy density laser, the temperature of the irradiated area increases and then cools, leading to re-crystallization and optimization of defective MoS2. This method can be completed in a very short time, thus avoiding other changes caused by prolonged exposure to heat. Furthermore, this experiment offers various adjustable parameters: the power level can be adjusted to process materials with different damage thresholds, and the processing range size can be controlled to process samples of different sizes.In this experiment, PL and Raman spectroscopy were utilized as detection systems. During the PL detection process, the sample is irradiated with a laser, causing electrons to transition to higher energy states. When these electrons return to lower energy states, they release energy and produce radiation, resulting in luminescence. Meanwhile, Raman spectroscopy detects defects within the material. These defects correspond to specific Raman spectral signals, enabling qualitative and quantitative analysis of defects in the material. Both methods allow us to confirm whether the MoS2 samples subjected to laser annealing optimize their defects and enhance their luminescence ability through re-crystallization.

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