Integration of Boron-Doped Diamond Microelectrode on CMOS-Based Amperometric Sensor Array by Film Transfer Technology

This paper reports on the fabrication of a complementary metal oxide semiconductor (CMOS)-based 20\times 20 amperometric sensor array integrated with boron-doped diamond (BDD) microelectrodes. The BDD electrodes were formed on a Si wafer at 800 °C, and then transferred to a 0.18 \mu m CMOS large-scale integration (LSI) wafer with a benzocyclobutene bonding interlayer. As a result, the BDD microelectrodes were arrayed without significant damage to CMOS circuit or BDD electrodes. The integrated BDD electrodes on the CMOS LSI exhibited excellent performance for electrochemical analysis. The wider potential window and smaller background current compared with Au microelectrodes were experimentally verified. The electron transfer rate to ferrocenemethanol as a standard reagent was large. The fully implemented device successfully detected 100-nm histamine, and was used for the 2-D real-time imaging of histamine diffused in a solution.