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

利用双极PBII在微/纳米沟槽上沉积了类金刚石（DLC）涂层，并利用相应的拉曼光谱检测了类金刚石膜在微/纳米沟槽表面的结构。采用细胞内粒子蒙特卡罗碰撞法计算了等离子体在沟槽周围的行为。结果，DLC薄膜成功地涂覆在沟槽的整个表面上。当外加负电压为-0.5 kV时，沟槽侧壁的DLC膜结构比上下表面的DLC膜结构更像聚合物碳。这是因为撞击侧壁的离子往往具有较少的入射能量。而在-15 kV的情况下，侧壁上的DLC膜更像石墨，尽管与顶部和底部表面相比，它的入射离子能量更小。等离子体模拟结果表明，这是由于沟槽底表面的溅射效应造成的。

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.