Advances in piezoelectric PZT-based RF MEMS components and systems

Abstract

There is continuing interest in radio frequency (RF) microelectromechanical system (MEMS) devices due to their ability to offer exceptional RF performance, high linearity and low power consumption. To date, there is an impressive amount of RF MEMS components such as; switches, resonators, varactors, and tunable inductors that have enabled smaller, cheaper and more efficient RF systems. RF MEMS devices contain micromachined components that have the ability to move so that a change in the mechanical state of a device will result in a change to the device’s RF properties. There are many common modes of actuation, including, but not limited to: electrostatic, magnetostatic, piezoelectric, and electrothermal actuation. Although there are attractive aspects and drawbacks to each of these technologies, this paper will focus on advances in the application of piezoelectric actuation, and in particular the use of lead zirconium titanate (PZT), for RF MEMS.

Metal‐bonding‐based hermetic wafer‐level MEMS packaging technology using in‐plane feedthrough: Hermeticity and high frequency characteristics of thick gold film feedthrough

“…[2][3][4][5][6][7][8][9][10][11][12][13][14] In so doing, leads must be drawn while maintaining vacuum, which is a problem especially in RF MEMS using low-resistance thick Au lines. 1 With high-frequency (RF) MEMS switches, internal space is usually retained in vacuum to prevent degradation of electric contacts, or to maintain switching speed through suppression of aid damping.…”

“…1 With high-frequency (RF) MEMS switches, internal space is usually retained in vacuum to prevent degradation of electric contacts, or to maintain switching speed through suppression of aid damping. [2][3][4][5][6][7][8][9][10][11][12][13][14] In so doing, leads must be drawn while maintaining vacuum, which is a problem especially in RF MEMS using low-resistance thick Au lines.Cap wafer bonding using glass frit, 5,15,16 feedthrough glass substrates, 7,17 anodic bonding of LTCC (Low Temperature Cofired Ceramic) substrates, 19,20 and other methods are long known techniques for wafer-level hermetic packaging of RF MEMS. The technique using glass frit is simple and convenient.…”

Growth of thin film ferroelectric PZT, PHT, and antiferroelectric PHO from atomic layer deposition precursors

“…Additionally, PZT has a large electromechanical coupling coefficient, which tends to a maximum at compositions near the morphotropic phase boundary (MPB) or PbZr 0.52 Ti 0.48 O 3 1 . Near‐MPB PZT has applications in commercial inkjet print heads 2–4 and emerging applications in piezoelectric microelectromechanical systems (PiezoMEMS) 5–7 . Compositions of PZT that are rich in PTO have commercial applications in ferroelectric random access memory (FRAM) due to the high remnant polarization ( P r ) and comparably low coercive field ( E c ) 8 …”

Tunable Inductors Using Integrated Vanadium Dioxide Phase Change Thin Films

“…The proposed research makes it possible for a novel tunable inductive structure with smaller size and straight forward manufacturing. The structure of the tunable inductor is a planar design with simple fabrication process, and the vanadium dioxide (VO 2 ) thin film stubs are used as switches instead of having any movable parts such as in a MEMS switch [7,8].…”