Area-selective
atomic layer deposition (ALD) is rapidly gaining
interest because of its potential application in self-aligned fabrication
schemes for next-generation nanoelectronics. Here, we introduce an
approach for area-selective ALD that relies on the use of chemoselective
inhibitor molecules in a three-step (ABC-type) ALD cycle. A process
for area-selective ALD of SiO2 was developed comprising
acetylacetone inhibitor (step A), bis(diethylamino)silane precursor
(step B), and O2 plasma reactant (step C) pulses. Our results
show that this process allows for selective deposition of SiO2 on GeO2, SiNx, SiO2, and WO3, in the presence of Al2O3, TiO2, and HfO2 surfaces. In
situ Fourier transform infrared spectroscopy experiments
and density functional theory calculations underline that the selectivity
of the approach stems from the chemoselective adsorption of the inhibitor.
The selectivity between different oxide starting surfaces and the
compatibility with plasma-assisted or ozone-based ALD are distinct
features of this approach. Furthermore, the approach offers the opportunity
of tuning the substrate-selectivity by proper selection of inhibitor
molecules.