Jessica C. Jones, Alex Martinson, Argonne National Laboratory, Lemont, IL
Minority atomic arrangement (i.e. defects) on surfaces exhibit distinct reactivity which allows for selective surface chemistry exclusively at those sites. We present an atomic layer deposition (ALD)-based technique of site-selective ALD (SS-ALD) targeting undesirable defect sites. Defects on the TiO₂ and other oxidized surfaces affect the electronic properties, interfaces, and performance of optoelectronic devices utilizing those interfaces. We present first principles calculations to predict the difference in hydration/hydroxylation of pristine TiO₂ terraces and minority atomic configurations (i.e. “defects”) including step edges and oxygen vacancies. In situ ellipsometry reveals the nucleation behavior of the SS-ALD at process conditions precisely tuned for selective hydroxylation of surface defects. An island growth model for nucleation and atomic force microscopy (AFM) imaging are consistent with a site-selective growth mechanism that depends on defect density.