以微波輔助化學氣相沉積法成長多晶鑽石薄膜的成長機制

鑽石是一種寬能帶隙的半導體。由於具有獨特且優異的物理性質，使得鑽石薄膜成為適合高溫及高功率電子元件應用的一種前瞻性材料。鑽石薄膜的電性與沉積參數之間有很大的相關性。有鑑於此，本文量測不同製程參數鑽石薄膜之拉曼光譜、掃瞄式電子顯微鏡、電導率，以評估個別製程參數對鑽石薄膜電性的影響程度，並深入探討鑽石薄膜的成長機制。實驗發現，在微波CVD的沉積參數中，「碳氫濃度比」及「微波功率」是影響鑽石薄膜鍵結型式及電性的兩個主要參數，而「氣體總流量」及「沉積室壓力」則是較為次要的參數。實驗也發現，鑽石薄膜的電導率並不是本徵電導率，而是反映鑽石薄膜中所包含的雜質及其他鍵結缺陷的能量狀態。由實驗數據可發現，沉積鑽石薄膜的表面化學反應乃是一種放熱反應。此外研究也發現，鑽石薄膜沉積速率是一種表面化學反應速率限制的機制。

關鍵字

鑽石薄膜；成長機制；沉積參數

並列摘要

Thin film diamond is a wide-bandgap semiconductor with outstanding physical and electronic properties making it a promising material suitable for high-power, high-temperature electronic applications. In this study, diamond films deposited at different combinations of processing parameters, including carbon/hydrogen ratio, microwave power, flow rate and deposition pressure, were fabricated to investigate the growth mechanism diamond films. The characterization techniques used in this systematic study included Raman spectroscopy, scanning electron microscopy, and conductivity measurements. It was found that carbon/hydrogen ratio and microwave power were the most important parameters while flow rate and deposition pressure were relatively unimportant in the determining the physical properties of diamond films. It was also found that the conductivities observed in diamond films were not the intrinsic conductivity. Instead, the observed conductivity was in fact the direct reflection of the impurities or other defect states present in the diamond films. Experimental results showed that the chemical reaction involved in the deposition of thin-film diamond was an exothermic reaction in nature. In addition, it could be deduced that the deposition process of thin-film diamond is limited by surface chemical reaction rate.

並列關鍵字

diamond films ； growth mechanism ； deposition parameters

國際替代計量

以微波輔助化學氣相沉積法成長多晶鑽石薄膜的成長機制

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