Space charge profile measurement techniques: recent advances and future directions

TLDR

Recent advances in space charge measurement techniques over the past five years are reviewed. The study proposes combining space charge techniques with CAFM to correlate 3‑D charge profiles with 2‑D conductivity maps for a fuller understanding of charge transport in dielectrics, especially nanodielectrics. To investigate thicker samples (~10 µm), CAFM would need to operate at higher voltages (~1000 V). Significant spatial resolution gains are unlikely in the next five years, except for LIMM with short laser pulses, which could reach ~100 nm, and this approach appears feasible.

Abstract

Some of the advances in space charge measurement techniques over the last 5 years are described. It is concluded that significant further improvements in spatial resolution are unlikely in the next 5 years, except in the case of the LIMM technique implemented using very short laser pulses, where spatial resolution approaching 100 nm might be achievable. It is suggested that existing space charge techniques be combined with conducting atomic force microscopy (CAFM), with the aim of correlating 3-dimensional space charge profiles and 2-dimensional conductivity maps and thus providing a more complete picture of charge transport through dielectrics, particularly in future work on nanodielectrics. Since CAFM samples are typically 5-10 nm thick, it would be necessary to operate the equipment at higher voltage (say 1000 V) so that samples not less than 10 /spl mu/m thick, e.g. polymers, could be investigated. This seems feasible.