Nano-SAW Devices for Wireless Identification

Surface Acoustic Wave (SAW) technology is omnipresent in the devices around us today, mainly used as passive bandpass filters in most radio systems like smartphones and TV antennas or as delay lines in telecommunications. More recently, the possibility to use SAW devices for wireless identification has surfaced and generated the first widespread applications such as on the highways in Norway over 2 decades ago. Their environmentally robust structure and passive use is very interesting for many applications in outdoor environments or chemically challenging places. It is possible to read many of them simultaneously and the amount of information that can be carried is much higher than printed barcodes. This semester project was aimed at learning how to design and fabricate an RFID device based on SAW technology in a cleanroom and trying to optimize the parameters of the device while reducing its size. Optical lithography tools with feature sizes down to 2 μm will help achieve this before E-Beam lithography can further decrease the features in scale of the structures involved in a SAW RFID tag. While creating an entire working wireless tag would take more time than available, the objective is to take this project as far as it can to pave the way for future students to search on this topic and increase knowledge about SAW devices.