T2.2: Technology improvements [M04-M12]

The goal of this task is to optimize the SAW fabrication process to reach the maximum performance of the future filter transduction structures. The quality of the device but also their capability to take advantage at maximum of the POI wafers including handling substrate optimized in WP3 is challenged, yielding routes for ultimate SAW properties on these substrates.
In that purpose, in parallel with the initial design task 2.1, technology developments are engaged by SOI to improve at best the SAW device operation. A set of synchronous single-port resonators is manufactured as close as possible from the frequency targets defined in WP1 to characterize the SAW properties near these operation points. The resonator scattering parameters Sij are measured for all the filters and converted as admittance and impedance parameters Y and Z to ease the FoM extraction in perspective of the design optimization task (T2.4).
Based on these tests, SAW performances will be pushed at maximum, particularly focusing on quality factors Q (resonance, antiresonance, Bode) that will condition the capacity of the filters to meet insertion loss requirements and the transition band sharpness. UCL and INC will provide accurate characterization of POI intrinsic electromagnetic properties derived in WP3, T3.1, the role of which in the global performances of SAW devices is investigated in close cooperation between SOI , UCL and INC.
On SOI side, efforts will be made in particular to reduce the impact of electrode nature and pattern on the electrical response of the resonators and hence filter demonstrator. Top side passivation will be also considered in that purpose. SOI will benefit from WP3 simulation and characterization results by INC to improve that feature. This task will require specific reticules to be generated and exploited. The quality of the device manufacture will receive a particular attention at this stage to fix the preferred technology parameters and technology-oriented design rules to favour at maximum the lithography/metallization compliance with the designed patterns.