Abstract: The present disclosure relates to a wafer-level packaged (WLP) bulk acoustic wave (BAW) device, which includes a BAW resonator and a WLP enclosure. The BAW resonator includes a piezoelectric layer with an interface opening, a bottom electrode lead underneath the interface opening, an interface structure extending over the interface opening and connected with the bottom electrode lead, a passivation layer with a passivation opening over the interface structure, and an oxide adhesion layer with an adhesion opening over the passivation layer. The WLP enclosure includes an outer wall directly residing over the oxide adhesion layer, and a through-WLP via encompassed by the outer wall and vertically aligned with the adhesion opening and the passivation opening. A portion of the interface structure is exposed to the through-WLP via through the adhesion opening and the passivation opening.

Abstract: The present disclosure relates to a wafer-level packaged (WLP) bulk acoustic wave (BAW) device, which includes a BAW resonator and a WLP enclosure. The BAW resonator includes a piezoelectric layer with an interface opening, a bottom electrode lead underneath the interface opening, an interface structure extending over the interface opening and connected with the bottom electrode lead, a passivation layer with a passivation opening over the interface structure, and an oxide adhesion layer with an adhesion opening over the passivation layer. The WLP enclosure includes an outer wall directly residing over the oxide adhesion layer, and a through-WLP via encompassed by the outer wall and vertically aligned with the adhesion opening and the passivation opening. A portion of the interface structure is exposed to the through-WLP via through the adhesion opening and the passivation opening.

Abstract: The claimed invention is directed to integrated energy-harvesting piezoelectric cantilevers. The cantilevers are fabricated using sol-gel processing using a sacrificial poly-Si seeding layer. Improvements in film microstructure and electrical properties are realized by introducing a poly-Si seeding layer and by optimizing the poling process.

Abstract: The claimed invention is directed to integrated energy-harvesting piezoelectric cantilevers. The cantilevers are fabricated using sol-gel processing using a sacrificial poly-Si seeding layer. Improvements in film microstructure and electrical properties are realized by introducing a poly-Si seeding layer and by optimizing the poling process.

Abstract: A software optimization system isolates an effect of a change in a control variable from effects of ongoing, unknown changes in other variables. The system discards effects due to noise so that effects of interest to a programmer are more easily visible. The software optimization system treats variations in one or more control variables and in the output of the system as signals. The system varies the control variable at a specific frequency unlikely to correlate with uncontrolled variations in external variables. The system uses digital signal processing (DSP) techniques to filter the output, isolating the frequency of the control variable variation. The system then compares the resulting filtered output to the input to determine the approximate effect of the variation in the control variable.

Abstract: The claimed invention is directed to integrated energy-harvesting piezoelectric cantilevers. The cantilevers are fabricated using sol-gel processing using a sacrificial poly-Si seeding layer. Improvements in film microstructure and electrical properties are realized by introducing a poly-Si seeding layer and by optimizing the poling process.

Abstract: The claimed invention is directed to integrated energy-harvesting piezoelectric cantilevers. The cantilevers are fabricated using sol-gel processing using a sacrificial poly-Si seeding layer. Improvements in film microstructure and electrical properties are realized by introducing a poly-Si seeding layer and by optimizing the poling process.

Abstract: A software optimization system isolates an effect of a change in a control variable from effects of ongoing, unknown changes in other variables. The system discards effects due to noise so that effects of interest to a programmer are more easily visible. The software optimization system treats variations in one or more control variables and in the output of the system as signals. The system varies the control variable at a specific frequency unlikely to correlate with uncontrolled variations in external variables. The system uses digital signal processing (DSP) techniques to filter the output, isolating the frequency of the control variable variation. The system then compares the resulting filtered output to the input to determine the approximate effect of the variation in the control variable.