Fine powder development for the Semicon market
The Semicon market is driven by a strong dynamic of technological progress and has seen its growth further boosted by the need of hardware for the deployment of 5G. Developments in wafer processing are key to meet the challenging miniaturization objectives set by the International Technology Roadmap for Semiconductors (ITRS). This roadmap follows the guideline of the so-called Moore’s Law, that predicts a doubling of transistor density within a given integrated circuit about every two years. Each generation of process is defined by its minimum feature size, referred to as technology node.
Currently most advanced fabs or foundries (semiconductor fabrication plants) operate with node sizes of 7 or 5nm and plants for 3nm are being built, participating in the ever-growing performance of our smartphones and electronic devices. Saint-Gobain supplies powders for the etching chamber coatings that protect the semicon processing equipment so our customers can meet the demands of the miniaturization roadmap.
How are the wafers turned into integrated circuits?
The main steps involved in the wafer processing are:
- Resist removal
- Wafer cleaning
During the dry etching process, the patterned wafer is exposed to reactive plasma (typically fluorine or chlorine based) that is also corrosive to the processing chamber material. Therefore, the internal components of the processing equipment is coated with protective ceramic layers.
What are the requirement for etching chamber protective coatings?
- Plasma resistance: yttria (Y2O3) is current state of the art but other materials are also considered for specific operating conditions
- Very dense: reducing the scale of the microstructure using fine powders for the thermal spray process helps limit the size and amount of defects that are detrimental to the corrosion resistance
- Smooth coating: etching equipment surfaces collect the etched material, the coating has to be smooth to help the cleaning process.
- Limited particle release (target zero particle): particles depositing on the wafer will generate defects that will only be detected at the testing of the chip, after several weeks of expensive processing.
- Regular thermal spray powder offering reaches limits: the one-size-fits-all approach currently in place in the thermal spray powder market won’t allow the key players in the industry to get to the next level of coating quality. The targeted extremely low level of defects requires complete adaptation of the powder to the process of the coating manufacturer.
- Define the blueprint of a product that does not exist yet: the features of the product that will enable the leap improvement coating shops are looking for are not known, as it is more than just a marginal gain of an iterative improvement on an existing product. With the help of Marketing, we went through discovery interviews to understand our customers’ painpoints. We understood which node technology equipment their coatings were currently serving and that they needed to adapt their offer to be able to serve the equipment going beyond those requirements. To reach this objective, the microstructure of the coatings needed to be refined and defect-free. Their concern was to get a finer powder adapted to this goal. This finer powder needed to have a narrow span and round shape to ensure proper feeding to the plasma spray torch. These particle characteristics lead to a stronger coating that resists the previously discussed breakage/dusting that result in defects. In addition to the challenges mentioned above, it was also necessary to maintain a high purity which can be more difficult with finer particle size distributions. This interview enabled us to open up the range of considered solutions and focus our efforts on their top priorities, so that we could implement solutions that weren’t considered in the past.
- Strong customer pull skipping the pilot phase: as the customer saw direct response to their key painpoint, the adoption time was reduced significantly (when it typically takes months to complete the qualification process). Indeed, between the time needed to develop adapted consumables like thermal spray powders, the time needed by the etch chamber coating jobshop to turn them into valuable coatings, and then testing time at the semicon equipment OEM, it is usual to spend several months per development iteration. The direct and quick adoption was a good surprise, but offered an additional challenge of a fast industrial ramp-up.
- Working in a fast changing environment (node technology changing every two years) requires agility and very close connection with the customer: from this observation, we decided to focus our efforts on a limited number of very promising customers based on their expertise and market knowledge. We set regular call with them and included our R&D team at least once a month. This way the priorities could be adjusted to follow the customer’s feedback and since then we manage to qualify new products every year
The successful development of an innovative and unique solution for Semicon equipment was made possible through the perfectly balanced interactions of Sales, Marketing, R&D and Manufacturing.
Manufacturing steps are shared between two Coating Solutions’ plants, in Northampton, MA, USA and in Avignon, France and balanced during development stage between these two locations to reduce leadtime. The US plant is dedicated to the thermal spray powders and is close to our Worcester headquarters that host the US sales and product manager team as well as the SGP Marketing. The Avignon plant, close to the SGR Provence transversal R&D center, holds the thermal spray competency and a development unit, the “Coating Cell” that could be used by the R&D team based in Cavaillon. Our value proposition for this very fine and high purity spherical yttria powder is clearly defined and we gained the necessary trust from our customers to share even more of their current challenges, so that we continue to strengthen our collaborative relationship and become their natural partner for new developments to go beyond their current technology node.
Some key projects are also focused on making our solutions more sustainable, there are a lot of challenges and opportunities for sustainable growth that Saint-Gobain is prepared to meet!