## 7 Prospects, Expectations, and Future Development
source, gas chemistry, and operating parameters requires a thorough understanding of these intricate interactions and trade-offs to ensure maximum process yield and long-term device reliability across diverse packaging platforms. Further experimental work, particularly in optimizing mixed-gas synergies and fully characterizing the long-term impacts of newer chemistries like NH\({}_{3}\) on various packaging architectures, remains warranted. _Main Concluding Points_  
In view of the complexity of the conclusions reached through this paper the following points are being presented as summary:  
* Trade-off in Plasma Source Selection: The comparative assessment of plasma sources reveals a distinct trade-off between performance and practicality. While electron cyclotron resonance (ECR) microwave systems demonstrate superior potential for efficient chemical processing, this is counterbalanced by their significant operational complexity and cost. In contrast, radio frequency (RF) systems offer a robust and more practical balance of process control and efficacy, explaining their prevalence in industrial applications. * Specificity of Process Gas Chemistry: The choice of process gas is dictated by the primary cleaning mechanism required. Oxygen excels at removing organic contaminants through oxidation, whereas hydrogen is highly effective for the chemical reduction of metal oxides. For physical cleaning via sputtering, inert argon remains the industry workhorse due to its efficiency and chemical neutrality. * Limitations of Specialized Chemistries: More complex chemistries present significant compromises. Nitrogen and ammonia, while offering passivation effects, exhibit lower cleaning efficacy and can negatively impact subsequent bonding processes. Halogen-based plasmas, despite their high reactivity, are generally unsuitable for lead frame applications due to their aggressive etching of silicon and metals, and severe toxicity. * The Principle of Application-Specific Optimization: A central conclusion is that an optimal plasma cleaning strategy is not universal, but is highly contingent upon the specific application. The selection of the source, gas chemistry, and operating parameters must be holistically determined by factors including the contaminants, substrate materials, required final surface condition, and constraints of subsequent process steps. * Future Development and Research Trajectories: Prospects for future development lie in the optimization of mixed-gas plasmas to leverage synergistic benefits and enhance cleaning efficiency. Further experimental work is warranted to fully characterize the performance, and long-term reliability impacts of emerging chemistries, such as ammonia (NH\({}_{3}\)), on diverse and advanced packaging architectures. **Funding:** The work underlying this paper was funded by the Research Fellowship Scheme which is financed by the Ministry for Education, Sport, Youth, Research and Innovation. Publication of this paper is also being supported by the MCAST research fund. **Acknowledgments:** The author wishes to acknowledge the Research Fellowship Scheme, and MCAST for supporting the project. This paper is part of project \"PlasmaSemiCon\". **Conflicts of Interest:** The author declares no conflict of interest.