A novel method for investigating electrical breakdown enhancement by nm-sized features
Hagay Shpaisman1, Hagai Cohen, Rotem Har-Lavan
1Department of Materials & Interfaces, Weizmann Institute of Science, Rehovoth 76100, Israel.
Nanoscale
|April 21, 2012
Summary
Determining the minimum voltage for electrical breakdown in thin dielectric films is crucial. This study introduces a novel model system using gold nanoparticles (Au NPs) to accurately measure breakdown voltage, revealing significant reductions with nanocontacts.
Area of Science:
- Materials Science
- Nanotechnology
- Electrical Engineering
Background:
- Electrical transport studies in nm-thick dielectric films are often hindered by local electrical breakdown.
- Nanoscale features can enhance electrical breakdown, complicating data acquisition and analysis.
- Accurate determination of the minimum breakdown voltage is essential for reliable device performance.
Purpose of the Study:
- To develop a model system for accurately measuring the minimum electrical breakdown voltage of dielectric-nanocontact interfaces.
- To investigate the influence of gold nanoparticles (Au NPs) on the electrical breakdown voltage of SiO(2) dielectric layers.
- To understand the interplay between nanoparticle size, defect density, and electric field strength in dielectric breakdown.
Main Methods:
- Fabrication of a model system using a 'floating' gold pad to contact Au nanoparticles (NPs) on dielectric films.
- Simultaneous measurement of numerous high aspect ratio NP-dielectric junctions to determine breakdown voltage.
- X-ray Photoelectron Spectroscopy (XPS)-based chemically resolved electrical measurements to pinpoint breakdown location.
Main Results:
- The breakdown voltage of a 48 ± 1.5 Å SiO(2) layer decreased from 4.5 ± 0.4 V for a flat contact to 2.4 ± 0.4 V with 5 nm Au NPs.
- Larger Au NPs did not necessarily lead to higher breakdown voltages, indicating complex size-dependent effects.
- Combined experimental and computational analysis revealed opposing effects of particle size: increased defect density and decreased electric field strength.
Conclusions:
- The developed model system effectively reveals the lowest electrical breakdown voltage for specific dielectric-nanocontact combinations.
- Nanoparticle size significantly impacts dielectric breakdown voltage through competing mechanisms.
- Understanding these breakdown mechanisms is crucial for predicting device vulnerability, such as to power grid spikes.
