Wang Bo, Zhang Ju-Fan, Dong Shen
School of Mechanical Engineering, Harbin Institute of Technology, Harbin 150001, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2008 Jul;28(7):1641-4.
The atmospheric pressure plasma polishing (APPP) is a novel precision machining technology. It performs the atom scale material removal based on low temperature plasma chemical reactions. As the machining process is chemical in nature, it avoids the surface/subsurface defects usually formed in conventional mechanical machining processes. APPP firstly introduces a capacitance coupled radio frequency (RF) plasma torch to generate reactive plasma and excite chemical reactions further. The removal process is a complicated integrating action which tends to be affected by many factors, such as the gas ratio, the RF power and so on. Therefore, to improve the machining quality, all the aspects should be considered and studied, to establish the foundation for further model building and theoretical analysis. The atomic emission spectroscopy analysis was used to study the process characteristics. A commercial micro spectrometer was used to collect the spectrograms under different parameters, by comparing which the influence of the RF power and gas ratio was initially studied. The analysis results indicate that an increase in RF power results in a higher removal rate within a certain range. The gas ratio doesn't show obvious influence on the removal rate and surface roughness in initial experiments, but the element compositions detected by X-ray photoelectron spectroscopy technology on the machined surfaces under different ratios really indicate distinct difference. Then the theoretical analysis revealed the corresponding electron transition orbits of the excited reactive fluorine atoms, which is necessary for further mechanism research and apparatus improvement. Then the initial process optimization was made based on the analysis results, by which the Ra 0.6 nm surface roughness and 32 mm3 x min(-1) removal rate were achieved on silicon wafers.
大气压等离子体抛光（APPP）是一种新型的精密加工技术。它基于低温等离子体化学反应实现原子尺度的材料去除。由于加工过程本质上是化学过程，它避免了传统机械加工过程中通常形成的表面/亚表面缺陷。APPP首先引入电容耦合射频（RF）等离子体炬以产生反应性等离子体并进一步激发化学反应。去除过程是一个复杂的综合作用，容易受到许多因素的影响，如气体比例、射频功率等。因此，为了提高加工质量，应该考虑和研究各个方面，为进一步的模型建立和理论分析奠定基础。采用原子发射光谱分析来研究工艺特性。使用商用微型光谱仪在不同参数下收集光谱图，通过比较初步研究了射频功率和气体比例的影响。分析结果表明，在一定范围内，射频功率的增加会导致更高的去除率。在初始实验中，气体比例对去除率和表面粗糙度没有明显影响，但通过X射线光电子能谱技术在不同比例下加工表面检测到的元素组成确实显示出明显差异。然后理论分析揭示了激发态反应性氟原子的相应电子跃迁轨道，这对于进一步的机理研究和设备改进是必要的。然后根据分析结果进行了初步的工艺优化，在硅片上实现了0.6 nm的表面粗糙度Ra和32 mm³·min⁻¹的去除率。
