Microwave examination of ferroelectric film quality

Abstract

Microwave methods for thin ferroelectric film parameter investigations are classified, discussed and improved. Being non-electrode and in some cases non-contact these methods are non-destructive and the information about parameters of films can be obtained from a distance and even during the technological process. High-resistivity silicon or semi-insulated gallium arsenide wafer adds little to microwave absorption or reflection. On the contrary, the crucial factor for the latter is the ferroelectric film with its microwave dielectric dispersion. It is assumed that some of microwave methods would be used in various stages of ferroelectric-semiconductor device characterisation.

Microwave study of ferroelectrics in waveguide

“…However, lucky for many microwave devices, BST film dielectric permittivity (ε film = 10 2 -10 3 ) is many times less than dielectric constant of ceramics (ε = 10 3 -10 4 ) that is very important for device matching with the microwave line. Temperature dependence of ε film is much smoothed comparing to bulk ceramics that provides more thermal stability of film based device [7].…”

“…Microwave methods of ferroelectric film investigations are examined in [7] and [8], while review [9] carried out the analysis of films parameters obtained at microwaves. There are only solitary mentions as to electrode-less study of ferroelectric film.…”

Microwave methods of ferroelectrics and related materials investigation

“…However, lucky for many microwave devices, BST film dielectric permittivity (Efilm = 10 2 -10 3 ) is many times less than dielectric permittivity of bulk ceramics (E = 10 3 -10 4 ) that is very important for device matching with the microwave line. Temperature dependence of Efilm is much smoothed comparing to bulk ceramics that provides more thermal stability of film based device [7].…”

“…Microwave methods of ferroelectric film investigations are examined in [7] and [8], while review [9] carried out the analysis of films parameters obtained at microwaves. There are only solitary mentions as to electrodeless study of ferroelectric film.…”

The Method of Waveguide-Junction Resonance for Integrated Ferroelectric Films Investigation

“…Fig.3 shows some results of resonant frequency f 0 calculations for Hoj of the fixture studied for "4sandwich" geometry in the 8mm waveband. The measured parameters are the frequency of the resonant transmission fo 0and correspondent Q-factor, that is quite enough to calculate the film C because microwave investigations of wafer should be obtained previously (14), (15). The dependence of frequency on waveguide radius {Fig.3a} is used to provide measurements at various frequencies /notice that the test fixture can contain several cells that have different radii and/ or different air gaps over the film/.…”