近年來，減碳意識抬頭，推動節能技術的發展，其中一項技術便是使用氮化鎵高電子遷移率電晶體建構高能源效率的電源轉換模組，由於它有較高的電子遷移率、電子飽和速度和耐熱性，使其在嚴苛的環境下有良好的表現，且可提高操作頻率，降低電容的需求，大幅縮減設備的體積。然而目前欠缺大尺寸且價格低廉的氮化鎵基板，在矽基板上磊晶即成為選項之一。本論文的研究是以矽基氮化鎵高電子遷移率電晶體為主軸，探討各式緩衝層結構對其垂直崩潰電壓的影響。此研究是使用有機金屬化學汽相沉積系統(Metal-Organic Chemical Vapor Deposition, MOCVD)沉積氮化鎵於矽基板上，在緩衝層中使用碳摻雜氮化鎵、超晶格結構和氮化鋁插入層結構來提高磊晶厚度至6 μm以上。並在磊晶過程中監控晶圓的曲率變化，避免晶圓翹曲或磊晶表面龜裂。經過適當組合，最終完成可承受1200伏垂直崩潰電壓的氮化鎵高電子遷移率電晶體緩衝層。;In recent years, the awareness of carbon emissions reduction has risen and the development of energy-saving technologies has been promoted. One of the technologies is to use gallium nitride high electron mobility transistors (HEMTs) to construct high energy-efficient power conversion modules. Due to its high electron mobility, electron saturation velocity and heat resistance, GaN HEMTs performance well in harsh environments. They can be operated at high frequency, which reduces the need for large capacitors in the switching circuits, and greatly decreases the size of the power conversion modules. However, large-size low-cost GaN substrates are not available currently. The growth of GaN on silicon has become one of the options for GaN HEMTs. The objective of this research focuses on high voltage (1200 V) GaN-on-Si HEMTs, especially the influence of buffer layer structures on their vertical breakdown voltage. In this study, we use a metal-organic chemical vapor deposition system (MOCVD) to deposit gallium nitride on (111) silicon substrates. Carbon doped GaN layers, superlattice structures, and AlN insertion layers in the buffer layer are used to increase the epitaxial thickness to more than 6 μm. The curvature of the wafers during the epitaxy process is closely monitored and controlled to avoid cracks of the films. Using a combination of the aforementioned structures, GaN HEMTs that can withstand a vertical breakdown voltage of 1200 voltage have been achieved.
