A small OCA on a 1×0.5-mm2 2.45-GHz RFID Tag-design and integration based on a CMOS-compatible manufacturing technology

This letter reports, for the first time, on the design strategy and process integration for a small on-chip-antenna (OCA) with a radio-frequency identification (RFID) tag chip-area ∼1×0.5 mm². It is designed based on a 2.45-GHz RFID tag circuit with an inductive-coupling model. A patterned Al shielding layer is used to improve the consistency of the actual performance obtained from fabricated devices and those predicated from the design. The antenna´s inductor coils were fabricated based on a conventional Cu-Damascene process. To achieve the required antenna performance (e.g., Q-factor), a set of thick USG and deep-via etch processes were specifically developed. Our results demonstrate that the dc power converted by the OCA is sufficient to enable the RFID tag chip to communicate with a corresponding 2.45-GHz RFID reader with a 1-mm distance.