Wafer level characterisation of microelectrodes for electrochemical sensing applications

Abstract

This work presents a system for the in-line wafer-level characterisation of electrochemical sensors. Typically, such sensors are first diced and packaged before being electro-chemically tested. By integrating their characterisation into the manufacturing process, the production of electrochemical sensors becomes more efficient and less expensive as they can be parametrically tested midway through the fabrication process, without the need to package them. This enables malfunctioning or failed devices to be identified before dicing and reduces costs as only functional devices are packaged (in many cases this can be more expensive than the sensor fabrication). This study describes wafer-level characterisation of a simple electrochemical sensor design using a photoresist hydrophobic corralling film for the electrolyte and a probe station for contacting to individual dies.