Processing and Properties of Screen‐Printed Lead Zirconate Titanate Piezoelectric Thick Films on Electroded Silicon

Abstract

The printing of lead zirconate titanate (PZT, Pb(Zr,Ti)O 3 ) piezoelectric thick films on silicon substrates is being studied for potential use as microactuators, microsensors, and microtransducers. A fundamental challenge in the fabrication of useful PZT thick-film devices on silicon is to sinter the PZT to high density at sufficiently low temperature to avoid mechanical or chemical degradation of the silicon substrate. The goal of the present study is to develop and implement suitable electrodes and PZT sintering aids that yield attractive piezoelectric properties for devices while minimizing reactions between the silicon, the bottom electrode, and the PZT thick film. A B 2 O 3 -Bi 2 O 3 -CdO sintering aid has been found to be superior to borosilicate glass, and the use of a gold/platinum bilayer bottom electrode has resulted in better thermal stability of the electrode/film structure. Films sintered at 900°C for 1 h have relative permittivity of 970 (at 1 kHz), remnant polarization of 20 C/cm 2 , coercive field of 30 kV/cm, and weak-field piezoelectric coefficient d 33 of 110 pm/V.

Hamaker 2: A Toolkit for the Calculation of Particle Interactions and Suspension Stability and its Application to Mullite Synthesis by Colloidal Methods

“…[15] This model, which includes the retardation effect, is included in the code as of version 2.1. The Hamaker constant is in this case calculated based on the dielectric constant e and refractive index n of the particles (subscript p) and medium (subscript m) as given by Equation (6) and used in the classical Hamaker equation as given in Equation (2). In Equation (6) x is the absorption frequency, c the speed of light, k the Boltzmann constant, and T the temperature.…”

“…[1] Cases where these interactions are of importance are, among others, the fabrication of high quality green bodies, for highly transparent ceramics, [2,3] or colloidal preparation routes for advanced powders, for example, by hetero coagulation. [4] Ceramic thin or thick films for porous films for ink-jet paper coatings [5] and piezoelectric screen printing applications [6] also depend greatly on the rheological properties and quality of dispersion. Interparticle forces also play a major role in the workability of cement and concrete pastes.…”

Electrophoretic Deposition of Pb(Zr, Ti)O3 Powder on Si Wafer: Morphological Change Across Film Thickness

“…To date, several methods have been proposed and researched. For example, screen-print technique 3 and composite film ComFi technology 4 were reported in literatures. The former has been widely used to produce more thick films ࢽ10 mm with large areas, but it is not easily adapted to the microfabrication and integration required for MEMS devices.…”

“…Due to the same reason, the small repulsion force between small particles facilitates the deposition i.e., coagulation of small particles side by side. Figure 5 shows the profile of the thickness of the PZT films as a function of deposition time for the PZT suspension containing 0.20 cm 3 HCl per 100 cm 3 . The relation between the film thickness and deposition time seems quite complicated.…”

Screen Printed PZT Thick Films Using Composite Film Technology

“…To realise Micro-Electro-Mechanical Systems (MEMS) capable of producing large deflections and high actuation forces it is necessary to incorporate thick piezoelectric elements [1]. Typical PZT thicknesses in such MEMS devices range from 5-100 µm.…”