Next-Gen Atomic-level Cleaning for state-of-the-art semiconductors and sub 20nm technology

In the article (https://www.researchgate.net/publication/301672352), D. H. Im et al. says the following statement in the introduction:

“Today’s sub 20 nm scale integration technology is strongly in need of an atomic scale controlling arising from the miniaturization of silicon devices”.

We at SisuSemi share this point of view – As semiconductor nodes become smaller, the focus is shifting towards atomic-level control and atomic-level cleanliness.

It's important to emphasize that it's not just about cleaning. The cleaned semiconductor surface needs also passivation so that it stays clean. In case the surface is not protected, native oxidation can cause significant challenges, as it is far from a crystalline oxide layer.

Traditional Methods for Surface Cleaning Discussed in the Article

The classical cleaning methods are wet and dry cleaning, that are also discussed in the article. Below is short summary from those technologies.

Wet Cleaning

• Advantages: Wet cleaning is an effective way to remove SiO₂.

• Limitations: It has critical limitations, such as low selectivity between SiO₂ and SiN, and SiO₂ and Poly Si. Additionally, native oxidation is a significant issue with wet cleaning.

• In other articles, the contamination caused by wet etching has also been highlighted to be an issue.

Dry Cleaning (Etching)

• Advantages: Dry cleaning is effective at removing oxides from the surface.

• Challenges: It can leave fluorine residues on the silicon surface, causing serious challenges for subsequent process steps. If the dry-cleaning process is not integrated into the next process inside a vacuum or protective environment, native oxidation of silicon surfaces can return, blocking smooth integration in the next process step.

Adding to challenges listed above, the article does not cover the atomic surface structure of silicon or other semiconductor materials.

In the dry etching process, the atomic structure is defected near and at the sub-surface level, causing un-ordered surface and unsmooth growth opportunities in subsequent process stages.

Hence, to achieve the best quality, we should challenge conventional thinking and explore novel solutions.

Importance of Atomic-Level Cleanliness

Achieving atomic-level cleanliness is crucial for the performance and reliability of semiconductor devices. Even the smallest contaminants can significantly impact electrical properties, leading to issues like increased leakage currents and reduced device lifespan. Maintaining pristine surfaces at the atomic scale ensures better conductivity and minimizes defects, which is essential for the miniaturization of silicon devices.

Traditional cleaning methods, wet and dry, have limitations with residuals, selectivity and atomic-level ordering. When we go to atomic level, we can see that they are not capable of providing the needed quality. Therefore, innovative solutions that address these challenges are vital for optimizing semiconductor manufacturing.

At SisuSemi, we offer advanced cleaning technologies that not only remove contaminants but also reorder the crystal structure of silicon surfaces. This ensures a clean, atomically smooth, and passivated surface ready for the next process step, significantly improving the electrical characteristics and overall performance of semiconductor products.

Novel Solutions

At SisuSemi, we offer a novel solution to remove native oxides, hydrogen, carbon, and other residues from silicon and other semiconductor surfaces. In addition to cleaning, we can re-order the crystal structure, which other technologies can not achieve.

Our process can be integrated seamlessly with the next process step, or we can provide a crystalline SiO₂ layer on top of the cleaned and re-ordered silicon surface. This offers significant improvement opportunities for the electrical characteristics and overall performance of semiconductor products, as we have already demonstrated with improved leakage current, and reduced defect density.

Reach out  and let’s see how we can work together.