Ceramic integration technology requires downsizing and/or improvement of device performance in many applications, such as in the fabrication of microelectromechanical systems, display devises, fuel cells, optical devices, and RF components. For these applications, realization of high-speed deposition rate, low process temperature, and fine patterning in ceramic coating are very important. The aerosol deposition (AD) method has many advantages for above requirements in comparison with conventional thin-film method or thermal spray coating technology. In this article, advantages of the AD method are highlighted by realizing a comparison with conventional thin-film methods and thermal spray technology. Challenges associated with AD method are also highlighted. At the end, examples of integration of AD method in the fabrication of electronic components are also given to show the easiness in usage and in integration of this method in the device process flow.

A novel method for depositing ceramic thick films by aerosol deposition (AD) is presented. Submicron ceramics particles are accelerated by gas flow up to 100-500 m/s and then impacted on a substrate, to form a dense, uniform and hard ceramic layer at room temperature. However, actual deposition mechanism has not been clarified yet. To clarify densification mechanism during AD, a mixed aerosol of a-Al 2 O 3 and Pb(Zr, Ti)O 3 powder was deposited to form a composite layer in this study. The crosssection of the layer was observed by HR-TEM to investigate the densification and bonding mechanism of ceramic particles. As a result, a plastic deformation of starting ceramic particles at room temperature was observed. J ournal

Lead zirconate titanate (PZT) films with a thickness of more than 10 µm were prepared by the aerosol deposition method and their microstructure and chemical composition were investigated by transmission electron microscopy (TEM) and energy dispersive X-ray spectra (EDX) analysis. A damage layer was observed at the interface between PZT and the Si substrate during the deposition. The microstructure of the as-deposited film at room temperature consisted of randomly oriented small crystallites with sizes of less than 40 nm and large crystallites of 100 nm to 300 nm size, which were observed in the primary powder. The Pb/Ti/Zr ratio along the film stacking direction and around the grain boundaries was almost the same as that observed inside the crystallites and the primary powder with a morphotropic phase boundary composition of (Pb(Zr 0.52 Ti 0.48 )O 3 ). The marked improvement of the electrical properties observed in the deposited films after annealing was mainly due to the crystal growth of small crystallites.

The infrared reflectivities of crystalline forsterite (Mg2SiO4) were measured for the temperature range 295–50 K for each crystal axis, between wavenumber 5000 and 100 cm−1. The reflection spectra show clear dependence of temperature; most of the bands become more intense, sharper and their peak positions shift to higher wavenumber with decreasing temperature. Reflection spectra were fitted with dispersion formula of damped oscillator model of the dielectric constants and the oscillator parameters in the model were derived. The absorption spectra of forsterite particle are calculated with the derived dielectric constants to show that the forsterite features are good thermal indicator for cold temperature range below 295 K.

Ultrawide range dielectric spectra from the kilohertz to terahertz range of BaTiO3 (BT), Ba(Zr0.25Ti0.75)O3 (BZT), (Ba0.6Sr0.4)TiO3 (BST), and SrTiO3 ceramics were presented by analyzing dielectric permittivity and IR reflectivity data. It was found that the permittivity of the ST was determined only by the ionic polarization while that of the BT was determined by the ionic polarization as well as the dipole polarization due to the domain contribution. The high permittivity of the BZT ceramics was attributed to the dipole polarization of polar nanoregions in the relaxors. The dipole and ionic polarizations overlapped in the BST.