透過氧電漿表面預處理提升柔性準凡德瓦爾磊晶品質

Abstract

本研究著重於探討氧電漿（O2 plasma）前處理對於在氟金雲母（F-mica）基板上成長氮化鎵（GaN）磊晶品質提升的影響。實驗使用了固定功率的氧電漿，並設置了四種前處理時間參數，分別是：未處理（pristine）、10分鐘、20分鐘與30分鐘，接著將這四種前處理完的F-mica基板送入氫化物氣相磊晶系統（HVPE），使用相同的參數成長GaN磊晶。研究發現，氧電漿的施打有助於成核與晶體品質的改善。 為了深入探討氧電漿的實際影響，本研究針對未處理與處理完的F-mica基板進行了AFM、XPS等分析，發現氧電漿的施打有助於粗糙度的提升，並影響F-mica表面的原子排列，進而改變後續磊晶的品質。此外，本研究結合了拉曼光譜與PL光譜的資訊，計算出GaN磊晶內的應力大小，更直接地呈現出不同樣品的品質差異，驗證出20分鐘的前處理時間為最適宜的參數。 最後，本研究針對品質最好的樣品進行了信賴度測試，透過週期性的彎曲樣品以及後續的PL光譜量測，實證了GaN磊晶在柔性F-mica基板具有一定的可靠性。這些研究成果證實了直接在新型二維材料上成長GaN磊晶的可行性，並成功開發出一種有效的表面改質方法。

This study investigates the effect of oxygen plasma (O2 plasma) pretreatment on improving the quality of gallium nitride (GaN) epitaxy grown on fluorophlogopite mica (F-mica) substrates. Using fixed-power plasma, four pretreatment durations were applied: pristine (untreated), 10 minutes, 20 minutes, and 30 minutes. The treated substrates were then used to grow GaN layers via hydride vapor phase epitaxy (HVPE) under identical conditions. Results show that plasma treatment enhances nucleation and crystal quality. Surface analyses using AFM and XPS revealed that oxygen plasma increases surface roughness and alters atomic arrangement, which benefits subsequent epitaxial growth. Raman and photoluminescence (PL) spectroscopy were used to evaluate internal stress in the GaN layers, confirming that 20 minutes of pretreatment yielded the best results. Reliability tests on the optimal sample, including cyclic bending and PL measurements, demonstrated that GaN on flexible F-mica maintains good stability. Overall, the study confirms the feasibility of direct GaN growth on 2D materials and presents an effective surface modification approach.