單晶碳化矽基板(Silicon Carbide, SiC)，具有高崩潰電壓(High Breakdown Voltage)及低的阻抗, 因此在高功率元件市場的潛力無窮，但單晶碳化矽基板也因高硬度及高抗化學性等特質，面臨加工時間冗長、成本過高等問題。本研究主要研究4H單晶碳化矽基板的化學機械拋光(Chemical Mechanical Polishing, CMP)製程以降低製程時間為目標進行研究。本研究建構一氣液輔助化學機械拋光系統(Gas Liquid Assisted Chemical Mechanical Polishing, GLA-CMP)，此系統將氧氣直接導入拋光液供給設備腔體至氧分壓達3 bar之壓力，以提升拋光液含氧量(~0.00396 mole/L)，增加其化學反應的速率，達到較高效率之拋光製程。研究方法先進行拋光液在不同氧分壓下溶氧量變化情形，並透過維克式硬度及接觸角驗證單晶碳化矽表面之反應層,後續將GLA-CMP應用於兩吋單晶碳化矽拋光標準片(As-polished wafer)及單面研光片(As-lapped wafer)，並分別使用能量散佈分析儀 (EDS)及X光光電子能譜儀(XPS)針對拋光後之表面進行元素分析，結果證實GLA-CMP相較於傳統CMP確實可以加速表面二氧化矽層之生成，本研究依據實驗結果建立一套材料移除模型，分析製程中各因子之影響。GLA-CMP應用於兩吋單晶碳化矽拋光標準片及單面研光片，平均材料移除率相較於傳統CMP製程提升了11.2%及16.3%；最後將GLA-CMP應用於四吋單晶碳化矽晶圓拋光標準片上，相較傳統CMP製程拋光移除率增益9.1%，應用於四吋單晶碳化矽晶圓雙面研光片上，以表面粗糙度Ra值0.10 nm為製程終點，可縮短26.3%製程時間，未來研究著重於試量產製程之研發測試。

Monocrystalline Silicon Carbide (SiC) substrate has high breakdown voltage and low resistivity electrical properties. It has a great potential for applying in high power devices. However, high hardness and brittleness result in long processing time of fabrication process. This study aims to enhance the
material removal rate (MRR) of chemical mechanical polishing (CMP) processes on 2 inch and 4 inch single-crystal silicon carbide wafer. A gas liquid assisted chemical mechanical polishing (GLA-CMP) method with adjustable high oxygen concentration has been developed with CMP slurry chamber (~3bar) by gas regulating device. The chemical reaction rate has been enhanced by high oxygen content (~68.54 mg/L). Experimental results successfully reveal that the substrate surface has obtained a reaction layer and verified via contact angle test, Vickers hardness, energy dispersive spectrometers (EDS), and X-ray photoelectron spectroscopy(XPS). From the results of EDS and XPS, the proportion of silicon oxide components on SiC surface after GLA-CMP process exists higher proportion than that after conventional CMP process. In this study, MRR has improved as 11.2% for 2 inch as-polished (As-Pol) SiC wafer, 16.3 % for 2 inch as-lapped (As-Lap) SiC wafer and 9.1% for 4 inch as-polished (As-Pol) SiC wafer. Additionally, the process time of planarization is reduced as 26.3% compared to that by conventional CMP process. Surface roughness (Ra<0.10 nm) is achieved with GLA-CMP for 4 inch SiC wafer (As-lap). Future study can focus on a movel slurry supply system for GLA-CMP of SiC wafer process.

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