Manufacturable Heterogeneous Integration for Flexible CMOS Electronics

Nearly sixty years back when Jack Kilby built the first integrated circuit (IC), it was also the beginning of today's advanced and matured complementary metal oxide semiconductor (CMOS) technology whose arts and science of miniaturization has enabled Moore's Law to double up the number of devices in a given area in every two years. It has also been possible because CMOS technology has consistently adopted new materials and processes. High performance (data processing speed in computational devices), energy efficiency (for portable devices) and ultra-large-scale-integration (ULSI) density - all these features have been added to every major technology generation in additive manner. As we go forward and embrace Internet of Everything (IoE) where people, process, device and data are going to be seamlessly connected, we may want to ask ourselves a few fundamental questions about the future of CMOS electronics, enabling role of CMOS technology, potential benefits and application opportunities. Physically flexible electronics are increasingly getting attention as a critical and impactful expansion area for the general area of electronics. Many exciting demonstrations have been made to point out to its powerful prospect. Due to the paradox that traditional crystalline materials based electronics are useful in data management but they are naturally rigid and bulky, most of the researchers have resorted to two strategies: (i) non-silicon based fully flexible system with limited functionality and (ii) hybrid flexible electronic system with off-the-shelf ICs for data management. We do not consider this paradox is fundamental and a block-by-block approach using traditional CMOS technology can allow us to build fully flexible CMOS electronic systems [Fig. 1].