製程壓力對於化學氣相沉積法在銅箔上成長石墨烯之影響

The effect of process pressure for the grapheme growth on copper foil via chemical vapor deposition

吳長紘(Chang-Hung Wu) ； 謝建國(Chien-Kuo Hsieh)

《真空科技》 32卷1期 (2019/03) Pp. 46-50

摘要

現今最常用來合成石墨烯薄膜的方法為化學氣相沉積法，以化學氣相沉積法所製備的石墨烯薄膜會因其成核的密度與成長機制而具備多晶結構，這也直接影響了石墨烯晶粒大小，所以石墨烯薄膜的成核密度在整個製程中是非常重要的，成核密度也因此在控制石墨烯薄膜的品質上扮演了一個非常重要的角色。因此，有需要清楚了解在材料特性的控制上影響石墨烯成核密度的參數如：退火時間，氫氣濃度，碳源種類，溫度，製程壓力以及氣體流場對於石墨烯晶粒的大小、密度等的影響都可藉由化學氣相沉積法來討論。在此篇論文中，我們藉由化學氣相沉積法的製程壓力來了解石墨烯晶粒在銅箔上之密度、面積、以及尺寸上的影響。研究結果顯示，低製程壓力下的銅蒸氣壓，會降低了從表面活化的碳原子，石墨烯薄膜較難橫向成長而導致較小的晶粒；另一方面，銅蒸氣壓則在常壓下被抑制住，進而獲得較大的石墨烯晶粒。因此銅蒸氣壓在石墨烯的合成上扮演了一個非常重要的角色。

關鍵字

石墨烯 ； 化學氣相沉積法 ； 製程壓力 ； 晶粒尺寸

並列摘要

The mostly used method for fabrication of graphene thin films is chemical vapor deposition(CVD), graphene films prepared by CVD on copper foils have polycrystalline structure, which is governed by the nucleation density and the relative growth kinetics. The nucleation density of graphene during the growth process is of fundamental importance since it determines the grapheme domain sizes, which, in turn, plays a crucial role in the material's quality. Therefore, a clear understanding of the CVD process parameters affecting the nucleation density of graphene is required for the controlling the characteristics and properties of graphene. The effects of growth parameters, such as annealing time, hydrogen concentration, hydrocarbon source, process temperature and gas flow of CVD are practically important on the influence of grain size and density of domains for the growth of graphene. In this report, the process pressure effect is studying for understanding the graphene domain density, area and size via CVD on copper substrate. The results show that the difference to a greater importance of copper evaporation under low background process pressure, where severe copper evaporation dictates the desorption rate of carbon atoms from the surface. On the other hand, the copper evaporation is suppressed at ambient pressure and resulted in a bigger graphene grain size. Therefore, the process pressure plays as an important role on graphene growth on copper substrate.

並列關鍵字

Graphene ； Chemical vapor deposition ； Process pressure ； Grain size