"Nanostructured materials have become an exciting area of research for the improvement of traditional electronic sensors. The high surface area to volume ratio of nanoflowers, nano-urchins, and nanoporous materials has allowed them to exhibit significant improvements in limit of detection and sensitivity compared to analogous planar sensors. These complex structures have also demonstrated the capability of improving biofouling resistance in complex media by helping to screen fouling agents from the active surface. Despite these advantages, moving this material beyond the laboratory has posed a challenge due to the high temperatures, often in excess of 500°C, and harsh chemicals required to produce repeatable structures. These are incompatible with traditional CMOS devices, which will break down at these temperatures and can suffer damage from long-term chemical treatment. As a result, the deployment of these newly developed materials has been stymied, and the promised improvements have been limited to the research setting in many cases.
In this work we propose a method of producing stable nanoporous gold structures on CMOS chips via co-deposition of silver-gold alloy onto CMOS pads, followed by a brief wet etch. We also propose a method of electrochemical deposition to deposit nano-urchin and nanoflower-like gold on CMOS pads. These methods require no elevated temperatures and limited exposure to etching chemicals, which prevents damage to the underlying CMOS structure. As a result, they are an excellent candidate for producing nanostructured sensors onto traditional CMOS dies, further supporting the push for “Lab on Chip” devices.
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Project is currently funded by: Federal