Microfluidic structures on CMOS dies

Customers will have access to all the key elements required for developing chip-based microfluidic subsystems – allowing them to move through the prototyping phase of their projects much quicker and get to a point where they can start considering full-scale production. By having numerous elements bundled together, it will no longer be necessary for customers to work with many different vendors. This means that the integration issues that generally come with complex multi-vendor projects can be avoided.

Leveraging X-FAB’s XH035 350nm high-voltage analogue/mixed-signal CMOS process, which is optimised for applications requiring high signal-to-noise ratios, the company can carry out numerous microfluidic post-processing activities. These can be undertaken at its state-of-the-art MEMS manufacturing sites in Germany, with use of multi-level mask (MLM) techniques to keep down the overall prototyping costs.

Customers will be able to benefit from the various standard process blocks that have been developed at X-FAB and are proven in silicon. Available process options include:

• Initial preparation of the CMOS wafer for microfluidic integration, through planarised passivation along with through passivation vias.
• The attaching of noble metal electrodes (either gold or platinum based) to act as interfaces for the fluidic samples.
• The adding of a dry film resist top layer (into which microfluidic channels can be scored) with an optional glass cap wafer.

To provide further assistance, the design house, testing operations and full turnkey suppliers in the X-Chain partner network can also be engaged with. This means that customers with limited prior expertise of creating a custom chip can always gain access to the services they need.

“Microfluidics represents a highly challenging application-specific market, requiring fully optimised custom solutions and considerable investment,” said Oliver Foellmer, Product Marketing Manager at X-FAB. “It is clear from our discussions with customers involved in this sector that they need to be able to get comprehensive prototyping support from a single source. Thanks to our new microfluidics prototyping platform, we are helping to accelerate development cycles and lower the financial thresholds, so that customers can embark on innovative silicon-based microfluidic projects regardless of their size or capabilities,” he concludes.

Customers can gain access to X-FAB’s new microfluidics prototyping platform straight away, with the initial prototyping run being scheduled for early Q1 2021.