Nanosurf, a leading provider of cutting-edge atomic force microscope (AFM) measurement equipment, offers fully automated, clean-room compliant AFM measurement solutions for the semiconductor industry. By providing measurement solutions for quality control, Nanosurf is a key contributor to the advancement of semiconductor industry. Through substantial experience with significant projects, we have refined our expertise, focusing particularly on the following essential areas.
Design Challenges and Solutions
Nanosurf’s AFM machines accommodate large and non-planar samples with up to several hundreds of mm in diameter, while still enabling complete sample coverage. AFM systems are typically known for hosting only small samples with a few mm or cm in diameter. The main reason for this is that for a small mechanical loop, i.e. the shortest track through the AFM hardware that mechanically connects the AFM cantilever tip and the actual measurement site, it is easier to achieve good system stability and thus low noise levels.
In contrast to conventional AFM systems, a large mechanical loop is inherent to systems that accommodate large samples. Achieving the required noise level (rms) on the pm scale on such systems is one of the main challenges that the engineering team s during system design and construction. We use finite element method (FEM) simulations to calculate the systems performance also taking into account mechanical disturbances. Operating at the physical limits these calculations need close collaboration with suppliers to properly model their components during the design phase.
Machine control and software is developed in parallel to the mechanical design process as meeting the challenging performance levels and strict safety requirements causes an interplay between mechanical design and control design. To achieve the required performance levels several rounds of system design evaluations with subsequent improvements as well as safety evaluations with adjustments of sensors and safe communication pathways are carried out. During the commissioning phase the actual user interaction with the machine has to be taken into account as well.
Automation and process-oriented Operation
Nanosurf’s industrial AFM measurement systems offer full automation of the whole sample analysis process, from loading the specimen, performing specimen-specific measurement routines through data links to factory control systems. This also includes automated cantilever exchange and sample re-positioning with sub-micron repositioning accuracy. A real time programmable logic control (PLC) is indispensable to ensure machine, specimen and human safety, finest motion control, and management of the AFM acquisition software.
A key aspect of the PLC interface is that it allows the operators who are not AFM experts to seamlessly run the machine by loading pre-defined operational sequences or “recipes”. For the operation different interfaces are realized, with a mobile panel allowing for direct interactions with the machine while being next to the sample and observing the different process steps while remote access functionality allows for service accessibility. The automation is developed in close cooperation with the customer and directly follows the process qualified for this step in the quality control.
Cleanliness and Compliance
In addition to the mechanical and control challenges, cleanliness requirements have to be considered along the whole process chain including design, production, commissioning, and operation. Nanosurf's machines are built to meet the stringent cleanliness requirements of the semiconductor industry. Of course, production is carried out in a cleanroom environment ensuring highly demanding industrial standards.
Commissioning and Project Management:
System commissioning during COVID times was a challenge that Nanosurf tackled head-on. Clean room clothing came in handy to protect the team working directly on the machine while the remote access reduced unnecessary travel and on-site presence, thus helping to keep the team healthy. In total, over 50 people, including Nanosurf employees, the customer team, suppliers, and external partners are involved in successful completion of these projects. This is only possible by careful planning and coordination as well as clear communication with all stakeholders.
Find out more about Nanosurf's advanced solutions for industrial applications: https://www.nanosurf.com/en/products/industrial-solutions