利用觸媒離子植入法與電子迴旋共振化學氣相沉積法合成碳奈米管

Abstract

這篇論文報導以離子植入與物理氣相沉積法將鈷、鎳金屬處理為觸媒， 再使用電子迴旋振化學氣相沉積法來控制碳奈米管的成長。 金屬觸媒分別以兩種氫電漿濃度為前處理。 濃的氫電漿會誘發較多的觸媒與積材鍵結， 並且經X-ray證明其形成矽化鈷晶體。 碳奈米管的成長機構控制於矽化鈷晶體而; 而矽化鈷晶體隨植入時間的長短與氫電漿濃度所影響而變化。 觸媒植入法有效減少非晶質碳的生成、並增加碳奈米管空管的大小、改變碳奈米管管數密度。 這些形貌的改變有以下的性質變化:Base-growth碳奈米管可以減少因為金屬觸媒殘留在Tip-growth 尖端的阻礙效應; 部份的碳奈米管是埋在基材內部， 被基材夾著， 因此增加了碳奈米管與矽基材的附著性; 較多的矽化物形成會降低缺陷的 ID/IG 比率。 另一特點是在試片傾倒45度電漿方向後， 可以使試片在電子迴旋振化學氣相沉積法中的碳米管沉積溫度降低到480℃。

This thesis reports ion implantation and PVD coating method; Co and Ni catalysts; and ECR-CVD used to manipulate the growth of CNTs. The catalysts were subjected two different H plasma pretreatment. Higher H plasma can enhance more bonding between implanted-cobalt and silicon substrate to form cobalt silicide crystal, which are provided by X-ray. The growth mechanisms of CNTs from tip-growth to base-growth also can be manipulated by cobalt silicide formation (control by implantation time and H concentration); more silicide formation often give rise to CNTs with lower ID/IG ratio. Effect of catalyst implantation can decrease a-C film formation on the specimen substrate, increase the hollow size and change the tube number density of CNTs. This morphology different was conformed to electric and mechanical properties change. As below: The base growth CNTs decreases the catalysts blocking effect on the tips of tip-growth CNTs and the implanted-catalyst-assist-CNTs are essentially embedded below the substrate surface, clipped by the surrounding Si walls and increase the adhesion property between CNTs and Si walls. It is interesting to note, the lower CNTs deposition temperature as 480℃ in ECR-CVD can be fabricated, as the specimen inclined on 45∘block with plasma direction.