Room‐Temperature ALD of Metal Oxide Thin Films by Energy‐Enhanced ALD

Abstract

Abstract Room‐temperature atomic layer deposition (RT‐ALD) processes are of interest for applications using temperature‐sensitive substrates. Challenges with RT‐ALD arise when the precursors are not sufficiently volatile, purge times become impractically long, and precursors or co‐reactants are unreactive with the surface species. In several cases, the latter two challenges can be overcome using energy‐enhanced ALD. Here, we demonstrate RT‐ALD (25°C) processes for Al 2 O 3 , TiO 2 , and SiO 2 from trimethylaluminum (Al(CH 3 ) 3 , TMA), titanium(IV) tetraiso propoxide (Ti(O i Pr) 4 , TTIP), and bis (diethylamino)silane (SiH 2 (NEt 2 ) 2 , BDEAS) precursors with an O 2 plasma or O 3 gas as co‐reactants. Saturated RT‐ALD growth was obtained for all O 2 plasma processes and TMA/O 3 , whereas the TTIP/O 3 and BDEAS/O 3 processes gave no growth. Using these and literature results, the criteria for viable RT‐ALD processes are discussed.