DLC Coating on a Micro/Nano-Trench by Bipolar PBII&D and Analysis of Plasma Behavior

采用双极PBII方法在微/纳米沟槽表面沉积了类金刚石(DLC)涂层，并利用其对应的拉曼光谱研究了DLC薄膜在沟槽整个表面区的结构。用粒子-胞内蒙特卡罗碰撞方法计算了沟槽周围的等离子体行为。结果，DLC膜被成功地涂覆在沟槽的整个表面。当外加负电压为-0.5KV时，DLC膜沟槽侧壁的结构比上、下表面的DLC膜更多地呈聚合物状碳结构。这是因为撞击侧壁的离子往往具有较少的入射能量。而在-15kV的情况下，尽管DLC膜的入射离子能量比顶面和底面的入射离子能量小，但侧壁上的DLC膜更像石墨。这归因于沟槽底表面的溅射效应，等离子体模拟证明了这一点。

Diamond-like carbon (DLC) coating was deposited on a micro/nano-trench by bipolar PBII, and the structure of the DLC film across the overall surface region of the trench was examined by making use of their corresponding Raman spectra. The plasma behavior in surrounding of the trench was calculated with Particle-In-Cell Monte Carlo Collision Method. As a result, DLC film was successfully coated on the overall surface of the trench. When the applied negative voltage was -0.5 kV, the structure of DLC film on the trench-sidewall became more polymer-like carbon than those of the top and bottom surfaces did. This is because the ions, which strike the sidewall, tend to have less incident energy. Whereas in the case of -15 kV, the DLC film on the sidewall was more graphite-like, despite of its smaller incident ion energy in comparison to those of the top and bottom surfaces. This is attributed to sputtering effect from the bottom surface of the trench, as evidenced by the plasma simulation.