Introduction
There have been developments and advanced research for the next-generation plasma nano processes through analysis of combinatorial plasma processes. The examinations carried out are aimed at determining the effectiveness and feasibility of the methodology based on surface morphologies and etching characteristics of plasma-polymer interactions (Setsuhara, Cho and Takenaka 6320). These two properties have been studied for PET films that have been exposed to mixture plasmas of argon and oxygen. The ion dose refers to the product of the exposure time and ion saturation current.
It was observed that an increase in the ion dose led to a slight increase in surface roughness of the polymer and a monotonic decrease of the mean spacing after plasma exposure (Setsuhara, Cho and Takenaka 6320). Photovoltaic cells and flat panel displays, among other applications require next-generation devices, which has led to the development of organic-inorganic hybrid systems. The success of these systems requires scientific understanding of plasma-polymer interactions and optimization of plasma processing of polymers in terms of physical and chemical properties (Setsuhara, Cho and Takenaka 6320).
Methodology
Combinatorial methods were used to develop a plasma process analyzer, in order to establish scientific basis of plasma nano processes. During the study, the combinatorial plasma-process analyzer used the density-inclination plasmas (Setsuhara, Cho and Takenaka 6321). The principle used to determine the feasibility of the density inclination plasmas was the sustenance of discharge by localized profile of discharge-power deposition through inductive coupling of RF power with low-inductance antenna (LIA) modules.
Localized deposition of discharge power was used to generate the density inclination plasmas (Setsuhara, Cho and Takenaka 6321). A cylindrical Langmuir with a platinum tip was used to measure ion saturation of current profiles along the substrate. The polyethylene terephthalate film used had a thickness of 100 μm.
Attention was given to the plasma exposure time since the undesired heating of samples could increase the etching rate. A stylus surface profiler was used to measure the etching depth of the PET films through exposure to plasma, in the five samples located at various positions. An atomic force microscope was used to observe the surface roughness f the PET films (Setsuhara, Cho and Takenaka 6321). Various surface texture parameters were evaluated in the analysis of changes in surface morphologies before and after exposure to the argon-oxygen plasmas. These parameters were the average roughness and average spacing between profile irregularities (Setsuhara, Cho and Takenaka 6321).
Results
Figures were used to illustrate the distribution of ion saturation current as a function of the substrate position, where one of the parameters was input RF power. The substrate position, x-220 showed the highest distribution of ion saturation current.
The methodology used in the study involved combinatorial plasma-process analysis. It was found to be significant since the process analyses could be carried out with multiple process conditions in one batch under the same wall condition (Setsuhara, Cho and Takenaka 6321). From the experiments, it was observed that a high ion dose to polymers was the main factor affecting the etching of polymers. It was also observed that a lower ion dose resulted in a slight etching depth, which was due to synergetic effects through co-irradiation with radicals and UV photons during the plasma process. Te roughness of the PET was seen to increase after exposure to the argon-oxygen plasma (Setsuhara, Cho and Takenaka 6321).
Discussion
During the treatment of plasma polymer surface, there was restructuring and cross-linking after plasma exposure, which led to surface morphological changes of polymer surface. Increased ion dose or etching depth was observed to propagate the surface roughness, a result of the formation of macro masks to roughen the surface. Etching processes in the experiment were successful and involved oxidation and ashing of the organic molecules from the PET surface. Etching of the film resulted in slight accumulation of surface roughness, causing a slight increase of surface roughness that was less than the etch depth (Setsuhara, Cho and Takenaka 6322).
Recommendations
Optimal process conditions can be achieved in the future development of these processes. One way is the control of organic-inorganic interface with a nanometer through bottom-up or top-bottom process. This would help to eliminate the try and error methods that are widely used. Plasma nano science would lead to the characterization of results based on the vital elements that determine the progress of plasma processes like energy distribution as opposed to conventional elements like gas pressure whose effectiveness depends on the apparatus (Setsuhara, Cho and Takenaka 6323).
Conclusion
The combinatorial method was used to develop the plasma-process analyzer. This allowed the effective conduction of process examinations with successive alterations of the conditions. The analyzer was capable of providing a wide range of ion flux according to the profiles of the ion saturation current along the substrate holder. An ion flux of forty was possible, in a single batch of the experiment (Setsuhara, Cho and Takenaka 6324 ).
Works Cited
Setsuhara, Yuichi, et al. “Advanced research and development for plasma processing of polymers with combinatorial plasma-process analyzer.” Thin Solid Films (2010): 518, 6320–6324.