Dielectric-on-Dielectric Achieved on SiO₂ in Preference to W by Water-free Chemical Vapor Depositions with Aniline Passivation

Selective and smooth dielectric-on-dielectric was achievedby water-freesingle-precursor chemical vapor deposition (CVD) processes with thehelp of aniline passivation. Aniline selective passivation was demonstratedon W surfaces in preference to SiO2 at 250, 300, and 330 degrees C. After aniline passivation, selective HfO2, Al2O3, and TiO2 were deposited only onthe HF-cleaned SiO2 surface by water-free single-precursorCVD using hafnium tert-butoxide Hf-((OBu)-Bu- t )(4), aluminum-tri-sec-butoxide (ATSB), and titanium isopropoxide Ti-((OPr)-Pr- i )(4) as the precursor reactants, respectively. Hf-((OBu)-Bu- t )(4) and Ti-((OPr)-Pr- i )(4) single-precursor CVD was carried out at 300 degrees C, while the ATSB CVD process was conducted at 330 degrees C.HfO2 and Al2O3 nanoselectivity testswere performed on W/SiO2 patterned samples. Transmissionelectron microscopy images of the W/SiO2 patterned samplesafter deposition demonstrated nanoselectivity and low surface roughnessof HfO2 and Al2O3 deposition on theSiO(2) regions only.