Dielectrics

Techniques: I-V, C-V, P-E, impedance, capacitance, permittivity, dielectric constant/loss, grain size
Applications: PC Memory, FeRAM, actuators, accelerometers, microphones, ink-jet heads, sensors
Types: Ferroelectric, piezoelectric, MEMs, NEMs, multiferroics, thin film, PZT, Barium Titanate, Perovskite, high-K, low-K

Dielectric materials are non-conductors of electricity (electrical insulators) that are able to be highly polarized by an electrical field (this is expressed as the material’s dielectric constant). Charges within dielectric materials can be displaced from an equilibrium position by an electric field, and in some cases the charges may also be aligned to the applied field, but do not pass through the material. On removal of the electric field, the material returns to its original state and the time taken to do this is referred to as the relaxation period which is a characteristic of the dielectric material. Typical tests involve applying a varying electrical field (AC waveform), and monitoring the relaxation of the material as a function of its permittivity (capacitance and conductance) vs. the applied AC frequency.

Dielectric materials are used in many applications such as:
  • Electronic components such as capacitors (responsible for energy storage properties of the device)
  • High-K / low-K materials widely used in Semiconductors to enhance performance and reduce device size (where K refers to permittivity or dielectric constant)
  • Dielectric materials are also used in Display applications (e.g. LCD liquid crystal displays)
  • Piezoelectrics/Ferroelectrics/MEMs materials are also dielectrics
  • Ceramics and Polymers also often exhibit dielectric properties
  • Many other materials / applications

Solartron Analytical’s range of materials test equipment is ideally suited for the characterization of dielectric materials. Key elements of testing are frequency range, range of electrical stimulus, range of impedance/permittivity/capacitance that can be measured, accuracy of measurements (especially at extreme impedance levels), control of applied temperature, and use of appropriate sample holders.

Solartron Analytical provides the following test systems for the characterization of these materials:
  • The ModuLab XM MTS Test System provides complete time domain/AC device characterization using an extensive range of “Plug and Play” options: 
  • The Model 1260A Impedance Gain Phase Analyzer is referenced in thousands of publications and is able to test capacitance/ C-V / impedance / Mott-Schottky from 10 µHz to 32 MHz (over 12 decades of frequency); enabling full characterization of ferro/piezoelectric materials
  • The Model 1296A Dielectric Interface System extends the impedance range of the 1260A to >100 Tohm in addition to providing greater accuracy by use of sample/reference techniques, and is often used in semiconductor applications
  • Temperature control options including Cryostats and Furnaces are available with all of the above measurement systems that provide automatic PC control of the sample temperature and allow complete material characterization