Wafer-level heterogeneous integration of electrochemical devices and semiconductors for a monolithic chip

Micro-scale electrochemical devices, despite their wide applications and unique potential to achieve 'More than Moore's law', face significant limitations in constructing functional chips due to their inability to integrate with semiconductors. In this study, we propose an electrochemical gating effect and material work function matching criteria, and thus establish the first heterogeneous integration theory for electrochemical devices and semiconductors. Accordingly, we create a novel 3D integration architecture and CMOS-compatible fabrication methodology, including optimizing individual devices, electron/ionic isolation, interconnection, and encapsulation. As a demonstration, we integrate electrochemical micro supercapacitors with a P-N junction diode rectifier bridge circuit and successfully obtain the first monolithic rectifier-filter chip, which shows a revolutionary volume reduction of 98% compared to non-integrateable commercial products. The chip can provide a stable output with a tiny ripple factor of 0.23% in typical conditions, surpassing the requirements of most applications by more than one order of magnitude. More importantly, all the processes are suitable for mass production in standard foundries, allowing ubiquitous applications of electrochemistry in integrated electronics.