Tiny atomic leaks undermine the promise of a nano-thin electronic insulator

A 2010 claim that an aluminum oxide/titanium oxide nanolaminate could deliver a giant dielectric constant was later shown to be a measurement artifact caused by leakage paths in the first aluminum oxide layer formed during atomic layer deposition. The aluminum oxide layer didn’t grow evenly because the TMA precursor pulled oxygen from the underlying TiO2, creating weak spots. Once the process used ozone as the oxygen source, leakage was suppressed and the material behaved as a true insulator, highlighting that chemistry at a few atomic layers can be as decisive as thickness for reliable dielectrics.