Next-Gen Atomic-level Cleaning for state-of-the-art semiconductors and sub 20nm technology
Improving silicon surface cleaning is essential for enabling reliable device performance as semiconductor nodes continue to shrink. Even microscopic residues and surface imperfections can lead to interface defects, yield loss, and long-term reliability challenges. In this article, we explore next-generation atomic-level cleaning approaches that help semiconductor manufacturers achieve cleaner surfaces, better electrical consistency, and stronger device integrity in advanced IC production.
Why Improving Silicon Surface Cleaning Matters
In the article (https://www.researchgate.net/publication/301672352), D. H. Im et al. states:
“Today’s sub 20 nm scale integration technology is strongly in need of an atomic scale controlling arising from the miniaturization of silicon devices.”
At SisuSemi, we share this view. As semiconductor nodes shrink, focus is shifting toward atomic-level control and cleanliness. Importantly, cleaning alone is not sufficient: the cleaned surface must also be passivated to maintain its pristine state. Without protection, native oxidation can introduce significant challenges, as it forms a non-crystalline oxide layer.
Traditional Methods for Surface Cleaning
The article discusses classical wet and dry cleaning methods. Here’s a summary:
Wet Cleaning
- Advantages: Effective at removing SiO₂.
- Limitations: Low selectivity between SiO₂ and SiN, or SiO₂ and Poly Si. Native oxidation is a significant challenge.
- Other studies highlight contamination caused by wet etching as an issue (source).
Dry Cleaning (Etching)
- Advantages: Effective at removing oxides from the surface.
- Challenges: Can leave fluorine residues that complicate subsequent process steps. If not integrated in a vacuum or protective environment, native oxidation can return, hindering smooth integration.
Moreover, classical methods do not address the atomic-level structure of silicon. Dry etching can create defects at the sub-surface level, resulting in an un-ordered surface that hampers smooth growth in subsequent processes. This highlights the need to challenge conventional approaches and explore novel solutions.
Importance of Atomic-Level Cleanliness
Atomic-level cleanliness is critical for semiconductor performance and reliability. Even minor contaminants can affect electrical properties, causing increased leakage currents, reduced device lifespan, and compromised conductivity. Traditional cleaning methods cannot ensure atomic-scale smoothness and ordering. Innovative approaches are therefore essential for optimizing semiconductor manufacturing.
At SisuSemi, our advanced cleaning technology not only removes contaminants but also reorders the crystal structure of silicon surfaces. This results in a clean, atomically smooth, and passivated surface, ready for the next process step, significantly improving electrical characteristics and overall device performance.
Novel Solutions by SisuSemi
Our process removes native oxides, hydrogen, carbon, and other residues from silicon and other semiconductor surfaces. Beyond cleaning, we reorder the crystal structure—a capability that conventional technologies cannot achieve.
Our solution can be seamlessly integrated with subsequent process steps or include a crystalline SiO₂ layer on top of the cleaned surface. This approach has demonstrated measurable improvements in electrical performance, including reduced leakage current and lower defect density, as documented in our case studies.
As semiconductor architectures evolve, improving silicon surface cleaning will remain one of the most impactful levers for reducing defects and maintaining strong yield performance. To learn how atomic-level cleaning technologies can be implemented in practice, contact the SisuSemi team or explore our latest resources on surface quality and contamination control.
Improving silicon surface cleaning for atomic-level cleanliness FAQ
Atomic-level cleanliness refers to a surface condition where also atomic level contaminants like Carbon, Hydrogen, and metals are removed, Silicon crystal structure has been recovered. To protect this atomic-level cleanliness SisuSemi is growing a thin crystalline Silicon-dioxide layer to protect the surface from re-contamination and natural oxidation after the cleaning process. In advanced semiconductor processes, surface condition is important because it influences the starting point for subsequent process steps and drives the defect density.
Silicon surface preparation is a key part of process integration. Cleaning is used to reduce unwanted residues and surface-level contamination that can affect how subsequent layers form and how interfaces behave during manufacturing. The traditional particle level cleanliness is not sufficient to provide enough clean outcome when we go towards smaller node sizes.
Depending on the process environment and handling steps, surface contamination may include organic residues, particles, and oxidation-related surface changes. Controlling recontamination between steps can also be an important consideration.
Wet cleaning typically uses chemical solutions to remove residues and contaminants, while dry cleaning approaches are used to prepare surfaces without liquid processing. The most suitable approach depends on the process requirements, materials, and integration constraints. Either of these process methods is not fully capable of tackling atomic-level cleanliness described above.
As devices scale and interfaces become more sensitive, surface preparation and contamination control can become more critical to meeting tight process requirements.
Atomic-level cleanliness is best understood as a process goal rather than a single cleaning technique. To be able to obtain this process goal, the cleaning technology must integrate sufficient cleaning or atomic-level contaminants, method to recover crystal structure and prevent the recontamination of the surface. At this point SisuSemi’s solution is the solution known to have all these integrated into one process.
Key considerations include identifying likely contamination sources, selecting suitable cleaning approaches for the process step, and controlling exposure conditions that may lead to reoxidation or recontamination.
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