A Novel Circular SAW (Surface Acoustic Wave) Device in CMOS

The design, modeling and fabrication of a novel circular SAW device in CMOS (complementary metal oxide semiconductor) are introduced. The results obtained by Tigli and Zaghloul (2007) demonstrate that it is possible to design and fabricate SAW based sensors in CMOS with comparable performance to conventional devices. It is of great interest to improve the transfer characteristics and to reduce the losses of conventional rectangular SAW architectures for obtaining highly selective sensor platforms. Performance deficiencies of regular SAW devices in CMOS were addressed with this new architecture for improved performance. A 3D model for the novel architecture was constructed. A detailed finite element analysis was carried out to examine the transient, harmonic and modal behavior of the new architecture under excitation. The devices were fabricated in 0.5 mum AMI technology and the post processing was carried out using the methods developed by Tigli and Zaghloul (2005). The results demonstrate that it is possible to obtain highly oriented surface acoustic waves by using the novel circular architecture. A 17.4 dB insertion loss and a 10.8 MHz of 3dB bandwidth improvement were achieved when compared to a conventional rectangular device.