Temperature Measurements for Space Charge Measurements in Dielectrics using a Thermal Step applied by a Coolant Liquid

Abstract

Improvements in space charge measurements by thermal methods can be acquired via the thorough knowledge of the temperature distribution at the surface and across the samples. The present work addresses surface temperature measurements for the Thermal Step Method (TSM) with a flat, thin thermo-resistive sensing structure. A structure containing a sensitive part made of a 150 nm platinum film, sputtered on a $400 \mu m$ silicon wafer and covered by a 100 nm $Si_{3}N_{4}$ layer, has been manufactured and studied. Through data obtained by modelling and experimentally, it is shown that thermal temporal resolutions in the $\mu s$ range can be obtained with the proposed device. The analysis is extended toward sensors made directly on polymeric substrates. Such setups will help to better estimate space charge distributions in relatively thick samples.