Insulating Epitaxy on N-SiC Wafer
Silicon carbide (SiC) offers significant advantages over silicon (Si) as a high-frequency electronic substrate, including superior thermal conductivity, mechanical stability, higher breakdown voltage, wider bandgap, and enhanced electron mobility. These properties enable effective electric field isolation and reduced leakage current, making SiC ideal for high-power RF applications. This project explores heteroepitaxy on secondary n-type SiC substrates to mitigate leakage current and recover manufacturing costs. A high-resistivity C-GaN layer will be grown on n-type SiC to improve electrical performance, forming a C-GaN/intermediate layer/n-SiC structure for high-frequency small-cell base stations.
The two primary challenges addressed are (1) electrical performance and (2) mechanical stability. By the way, epitaxial growth introduces mechanical stress and wafer warpage, affecting yield. To optimize growth success, this project collaborates with National Central University for C-GaN epitaxy. Through interdisciplinary efforts, this research aims to optimize heteroepitaxy on secondary n-type SiC, providing a cost-effective solution for high-frequency applications.
Keywords: 6H n-type SiC、semi-insulating epitaxy、RF components、wafer bow
碳化矽（SiC）相較於矽（Si）作為高頻電子元件基板，具備諸多優勢。SiC具有優異的熱傳導性與機械穩定性，可顯著提升元件的可靠性，對於高功率射頻應用尤為關鍵。此外，SiC具備更高的耐壓能力、更寬的能隙以及更高的電子遷移率，使其在高頻與高功率應用中能有效隔離電場並降低漏電流，展現優越的電性表現。本計畫擬針對次級 n 型 SiC基板進行表面改質，以克服其高導電率所導致的漏電問題，藉此提升次級 SiC 基板的應用價值，並挽回部分製造成本。本研究將於n型SiC基板上磊晶高電阻率之C-GaN層，以改善漏電特性，並最終形成C-GaN/中介層/n-SiC結構，應用於小型基地台之高頻元件。
本計畫主要聚焦於兩大關鍵問題：(1) 電性改善與 (2) 機械穩定性。此外，磊晶製程將導致機械應力與翹曲問題，進而影響磊晶品質與製程良率。為提升磊晶成功率，將執行預壓應力膜試驗，以探討其對磊晶翹曲的影響，本研究將透過跨領域合作，優化次級n型SiC基板的異質磊晶技術，期望為高頻元件應用提供具成本效益的解決方案。
關鍵字：6H型n-type SiC、絕緣磊晶、射頻元件、晶圓翹曲
