Integrated microstructures fabricated with seamless integration technology    What kind of technology is it? By expanding Si-core technology, we have developed micro-fabrication technologies for feature sizes of 10μ or more to achieve the seamless integration of LSIs or photonic devices with microelectromechanical system (MEMS) devices. We call this Seamless Integration Technology (SeaiT). Figure 1 illustrates the concept behind this technology, which allows structures such as miniature sensors and electrodes with sizes ranging from 10μ to 1 mm to be integrated on LSIs. The integration of such elements on LSIs makes it possible to implement new functions that cannot be achieved with conventional LSIs alone.        What are the features? Hitherto, in sensors and devices using MEMS technology, the MEMS structures have been fabricated on different chips from the other elements, thus making it difficult to produce miniaturized high-performance devices. Our Seamless Integration Technology can overcome this problem because it allows MEMS structures to be fabricated directly on the top of LSI circuits.      What can it do? Seamless Integration Technology makes it possible to fabricate MEMS structures on LSIs. Figure 2 shows a fingerprint sensor consisting of a sensor array structure fabricated on the top of an LSI. Figure 3 shows an optical micromirror array consisting of miniature mirrors that are controlled by electrodes fabricated on a Si substrate. Figure 4 shows an integrated RF-MEMS chip with spiral inductors and RF switches. Figure 5 shows a very small cavity structure encapsulated by spin-coating film transfer and hot pressing (STP) technology.