Ultra-Thin Chips on Foil for Flexible Electronics

Plastic electronics, thin-film-transistors on foil and ultra-thin chips on foil are technologies currently pursued to support the strongly emerging market for flexible electronics. Ultra-thin CMOS chips [1] on foil will not only provide solutions whenever high circuit performance and/or complexity are required but also in a heterogeneous integration with organic or TFT electronic components on foil, such as for flexible displays. Thinning of conventional CMOS chips in post-processing tends to be unreliable and costly due to difficulties in the control of the grinding process applied to fully processed CMOS wafers [2] or the need of employing expensive silicon-on-insulator (SOI) and handle substrates [3].