Our digital civilization is built on billions of electronic devices that seamlessly operate everyday ranging from a television remote to extremely complex systems like the International Space Station. All of these were started by the invention of the first solid-state transistor and were revolutionized by complementary-metal-oxide-semiconductor (CMOS) technology in 1963. The new technology paved the way for high density integration of electronics and enabled very-large-scale-integration (VLSI) schemes which eventually became the fundamental building block of all high-performance computation (HPC) systems. However, real-world applications always demanded a form of analog conversion to digital equivalent to connect sensors and actuators. Integration of an analog system into a digital system is challenging, if not impossible, which has always been demanding extensive research and development (R&D) programs. Accordingly, micro-electro-mechanical-systems (MEMS) were invented as a solution for scaling analog systems needed for denser integration. Fortunately, CMOS microfabrication techniques were utilized to facilitate manufacturing of MEMS devices and offered heterogenous integration with CMOS chips that opened up virtually endless combinations in product development. Nonetheless, scaling trend in micro-electronics industry resulted in monolithic integration of MEMS structures with CMOS devices; this revolutionary technology is known as MEMS-on-CMOS which offers unprecedented performance but at a higher complexity.
MEMS-on-CMOS is considered a revolution but is bounded with CMOS manufacturing process limitations; only planar devices can be made with the current state-of-the-art microfabrication schemes. Three-dimensional (3D) integration, however, not only allows a denser integration by utilizing the third dimension but also offers comparably higher performance metrics as the surface area is an order of magnitude larger in a 3D space. At DUJUD, we have introduced the third revolution in the micro-electronics industry: 3D-on-CMOS. Our proprietary 3D additive micro-fabrication technologies enable monolithic-like manufacturing of 3D MEMS devices on CMOS chips at wafer-scale. This capability creates a large design space that was previously unattainable with conventional 2D CMOS microfabrication technologies. The first commercially available 3D-on-CMOS process will not only speed up mass manufacturing from months to weeks (supply-chain advantage) but is also the only true 3D manufacturing scheme at micron-scale.