Reactive pulsed laser deposition of low particulate density and epitaxial TiN films on Si (100) for functional oxide integration

Abstract

• Low particulate density epitaxial TiN on Si (100) is deposited via reactive PLD. • Plume chemistry (N/Ti) alters the structure and microstructure of the TiN film. • TiN films roughen in RPLD process under low N availability. • Edge mobility along ><˃˄110> TiN limits the lateral growth rates. • Ferroelectric BaTiO 3 is epitaxially integrated on reactive PLD TiN/Si. Epitaxial TiN films on (100) Si have been realized by reactive pulsed laser deposition (PLD). Their utility is demonstrated by subsequent growth of epitaxial BaTiO 3 . PLD geometry optimization has yielded TiN films with a low particulate density, ∼ 6 × 10 3 cm −2 , but with a growth rate, ∼1 μm/hr, comparable to the standard On-axis geometry. The method of heat up to growth temperatures yields oxide free epitaxial interface, (001) TiN ||(001) Si and <100> TiN ||<100> Si and ω-scan full width at half maximum of 1.2° in symmetric and asymmetric geometries. Repetition rate and fluence effect studies have resulted in films with a surface roughness of < 5 nm as required for device fabrication. Parameters that increase surface roughness also raise oxygen incorporation. A BaTiO 3 -TiN-Si stack, (001) BaTiO3 ||(001) TiN ||(001) Si and <100> BaTiO3 ||<100> TiN ||<100> Si , is demonstrated with switchable out of plane polarization.