A comparative study of the microstructure-dielectric properties of crystalline SrTiO3 ALD films obtained via seed layer approach

SrTiO3 (STO) films were grown by atomic layer deposition (ALD) on TiN using Sr(t‐Bu3Cp)2, Ti(OCH3)4 and H2O. After crystallization anneal, large single crystals grains were obtained and nanocracks were present. The microstructure can be changed using a thin STO crystalline seed spike annealed at 700 °C, which induces formation of much smaller grains in the top layer after post‐deposition anneal. The seed approach was also applied for a layer that was directly deposited in crystalline state at 370 °C, with a Ti(Me5Cp)(OMe)3 precursor thermally stable at this temperature of deposition. The nanocracks were reduced or totally eliminated when using the seed layer template approach. Nevertheless, the leakage current is only reduced for the case when the Ti(OCH3)4 precursor was used.