Impact of a Trap-Rich Layer on the Performance of D-BAW Resonators

This research relies on the double-side-patterning bulk acoustic wave (D-BAW) technology framework and meticulously designs and fabricates a thin-film bulk acoustic wave (FBAR) resonator equipped with a trap rich layer. By systematically comparing the parameter characteristics and corresponding filter frequency response curves of two different types of resonators, one with a trap rich layer and the other without such a structure, we reveal the significant inhibitory effect of the trap rich layer on charge carrier leakage phenomena. This characteristic directly results in an effective improvement in the quality factor (Q-factor) of the resonator and visibly optimizes the insertion loss performance of the filter. The experimental data clearly demonstrates that under identical conditions, FBAR filters utilizing the trap rich structure exhibit an absolute reduction of 1dB in their insertion loss compared to filters lacking this structure. This outcome effectively highlights the pivotal role the trap rich layer plays in enhancing the overall performance of the device.