Clean Technologies

The project aims to optimize the use of technical gases and refrigerants within the Fraunhofer-Gesellschaft. To this end, the status quo is first recorded and consumption analyzed. Innovative measurement technologies will determine precise consumption data, while continuous online exhaust gas measurement will show the unprocessed proportion of greenhouse gases. Finally, the climate impact of the gases will be evaluated and a concept for data collection developed in order to integrate the results into the greenhouse gas balance (GHG balance) of the Fraunhofer-Gesellschaft.

A common problem with MEMS devices operating under ambient conditions is the degradation of their active structures due to oxidation and moisture absorption. To reduce these effects, industrial applications often rely on PTFE (Teflon) as a hydrophobic protective layer. In view of the growing need for more environmentally friendly production methods, Fraunhofer IPMS is investigating alternative materials such as FDTS (fluorodecyltrichlorosilane) to replace PTFE. The aim is to maintain the protective function while ensuring the performance of ultrasonic devices such as Capacitive Micro-machined Ultrasound Transducers (CMUT). This technology plays a crucial role in medical technology, industrial automation and non-destructive testing.

Chemical-mechanical polishing (CMP) is an indispensable process in semiconductor manufacturing, but is associated with a high carbon footprint. In particular, the use of cerium oxide (ceria) in polishing slurries poses a challenge: Not only does it cause significant CO₂ emissions, it is also potentially carcinogenic and its availability is limited. Ceria slurries are currently mainly used in selective SON polishing steps, which are crucial for high-precision structures. Although silica-based alternatives are available, they limit the versatility in chip production and thus hinder the diversification of microelectronics. The development of new, environmentally friendly polishing solutions is therefore an important step towards meeting the requirements of modern semiconductor manufacturing and driving sustainability in the industry.

Development and evaluation of environmentally friendly, water-based cleaning technologies as an alternative to the petroleum-based solvents currently used in semiconductor production. These new processes should not only replace chemicals that are harmful to health and the environment, but also reduce the use of aggressive additives and the need for extensive wastewater treatment. As part of the project, important steps are being taken to test the cleanroom suitability, process stability and automation capability of the water-based solutions. In addition, their ecological savings potential along the entire process chain will be evaluated. The envisaged technology is intended to advance the semiconductor industry towards more sustainable production while meeting the high requirements for process reliability and efficiency.

N-methyl-2-pyrrolidone (NMP) is a widely used solvent in the semiconductor industry, especially for precise processes such as the structuring of thin layers (lift-off process) and the removal of lacquers for surface cleaning. These processes are crucial for ensuring the quality and performance of semiconductor components, for example in chip production and microelectronics. Due to its reprotoxic properties and irritation of the eyes, skin and respiratory tract, NMP was added to Annex XVII of the REACh Regulation in 2018. Since May 2020, the use of NMP in consumer products with a content of 0.3% or more has been banned in the EU.