Photonic integrated circuits (PICs) are gaining momentum as a manufacturing segment, driven by the superior data transfer speeds and energy efficiency they offer compared to conventional metal interconnects. As hyperscalers, telecom infrastructure providers and data-centre operators push for higher bandwidth at lower power budgets, photonics fabs are under pressure to differentiate their processes at the materials and interface level — an area where wet chemistry plays a decisive role.
RENA Technologies, headquartered in Gütenbach, Germany, positions its wet processing portfolio specifically for this environment. According to the company, it holds vendor-of-record status at several photonics fabs globally, supplying equipment and process know-how for critical wet steps in PIC manufacturing lines.
The technical challenge in photonics wet processing differs markedly from standard CMOS cleaning and etch sequences. PIC platforms — whether based on silicon-on-insulator waveguide structures, indium phosphide, lithium niobate or silicon nitride — involve chemically sensitive materials that cannot tolerate the aggressive chemistries common in conventional semiconductor wet benches. Interfacial engineering, including surface preparation prior to bonding, passivation and selective etching of optical layers, requires tightly controlled chemistry, temperature uniformity and particle performance to preserve waveguide loss budgets and coupling efficiency.
RENA describes its offering as a planning service combined with equipment supply: the company works with photonics fabs to map the required wet process steps for a given product, then pairs those steps with cost-optimised equipment configurations and chemical solutions suited to scaling from pilot to volume production. This fab-engagement model is consistent with approaches used in III-V compound semiconductor manufacturing, where process recipes and hardware are often co-developed rather than procured off the shelf.
From an equipment perspective, wet processing in advanced photonics encompasses single-wafer spray tools, immersion batch systems and specialised rinse-dry modules, each selected depending on the topology and material sensitivity of the wafer at a given process stage. Defect control and cross-contamination prevention are particularly stringent given that waveguide structures operate at optical wavelengths where nanometre-scale surface roughness translates directly into insertion loss.
For European electronics and semiconductor packaging manufacturers tracking the photonics supply chain, RENA's positioning is noteworthy. European investment in silicon photonics — supported in part by the European Chips Act and programmes such as the PhotonDelta ecosystem in the Netherlands and the Fraunhofer photonics network in Germany — is expanding the addressable market for specialised fab equipment suppliers. Wet processing, though less visible than lithography or deposition, is a process-critical bottleneck that can determine yield and ultimately the economics of PIC volume production.
RENA's focus on photonics wet processing reflects a broader industry trend of equipment suppliers developing application-specific variants of established wet bench technology to address emerging compound semiconductor and photonics workloads, rather than relying on process transfers from silicon CMOS.
Quelle: Rena (semicon) – https://www.rena.com/en/products/semiconductor/precision-wet-processing-solutions-for-advanced-photonics
