Dielectric-on-Dielectric Achieved on SiO 2 in Preference to W by Water-free Chemical Vapor Depositions with Aniline Passivation.

Selective and smooth dielectric-on-dielectric was achieved by water-free single-precursor chemical vapor deposition (CVD) processes with the help of aniline passivation. Aniline selective passivation was demonstrated on W surfaces in preference to SiO 2 at 250, 300, and 330 °C. After aniline passivation, selective HfO 2 , Al 2 O 3 , and TiO 2 were deposited only on the HF-cleaned SiO 2 surface by water-free single-precursor CVD using hafnium tert -butoxide Hf(O t Bu) 4 , aluminum-tri- sec -butoxide (ATSB), and titanium isopropoxide Ti(O i Pr) 4 as the precursor reactants, respectively. Hf(O t Bu) 4 and Ti(O i Pr) 4 single-precursor CVD was carried out at 300 °C, while the ATSB CVD process was conducted at 330 °C. HfO 2 and Al 2 O 3 nanoselectivity tests were performed on W/SiO 2 patterned samples. Transmission electron microscopy images of the W/SiO 2 patterned samples after deposition demonstrated nanoselectivity and low surface roughness of HfO 2 and Al 2 O 3 deposition on the SiO 2 regions only.