We report on the sol–gel deposition and characterization of high-quality, epitaxial films of PbZr.52Ti.48O3 (PZT) on (001)Si substrates, with a thickness range of 400 Å to 1 μm. The epitaxial growth of PZT on (001)Si is achieved using a thin template layer of SrTiO3, grown by molecular-beam epitaxy. The sol–gel PZT films have a typical surface roughness of 5 Å and exhibit well defined reflective high-energy electron diffraction patterns characteristic of smooth, epitaxial films. Using high-resolution transmission electron microscopy and double-crystal x-ray diffraction, we find that the PZT films are oriented with the c axis normal to the (001)Si plane and with the a axis lying along 〈110〉Si direction. Finally, we measure the electromechanical coupling coefficients and the surface acoustic wave velocities for our films as a function of thickness and compare our experimental data to previously published theoretical values for this system.

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Demands for mobile phones with smaller form factor and lower cost have driven enhanced integration of electronics components. However, surface acoustic wave (SAW) filters must be fabricated on piezoelectric substrates, and so they are difficult to monolithically integrate on semiconductor chips. This paper reports on a compact wafer-scale packaged SAW filter stacked over a transceiver chip in a quad flat-pack no-lead (QFN) package. An integrated passive device (IPD) provided redistribution and matching between the SAW filter output and the transceiver input. Both extended global system for mobile communications (EGSM) and DCS filters were evaluated. Results demonstrated that conventional packaging techniques can be used to successfully assemble stacked SAW on transceiver modules without damage. SAW compact models based on the coupling of modes model were developed to facilitate system design. Electromagnetic simulations of coupling between SAW filters and inductors integrated on the transceiver suggested that design care is needed to avoid interactions, especially if an IPD is not used as a spacer. With appropriate design, stacked SAW filter on transceiver offers viable module integration.Index Terms-Land mobile radio cellular systems, multichip modules, semiconductor device packaging, surface acoustic wave (SAW) filters.

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