Aw. Ott et al., ATOMIC LAYER CONTROLLED DEPOSITION OF AL2O3 FILMS USING BINARY REACTION SEQUENCE CHEMISTRY, Applied surface science, 107, 1996, pp. 128-136
Citations number
39
Categorie Soggetti
Physics, Condensed Matter","Chemistry Physical","Materials Science, Coatings & Films
Al2O3 films with precise thicknesses and high conformality were deposi
ted using sequential surface chemical reactions. To achieve this contr
olled deposition, a binary reaction for Al2O3 chemical vapor depositio
n (2Al(CH3)(3) + 3H(2)O --> Al2O3 + 6CH(4)) was separated into two hal
f-reactions: (A) AlOH + Al(CH3)(3) --> Al-O-Al(CH3)(2)* + CH4, (B) Al
CH3 + H2O --> AlOH* + CH4, where the asterisks designate the surface
species. Trimethylaluminum (Al(CH3)(3)) (TMA and H2O reactants were em
ployed alternately in an ABAB... binary reaction sequence to deposit A
l2O3 films on single-crystal Si(100) and porous alumina membranes with
pore diameters of similar to 220 Angstrom. Ellipsometric measurements
obtained a growth rate of 1.1 Angstrom/AB cycle on the Si(100) substr
ate at the optimal reaction conditions, The Al2O3 films had an index o
f refraction of n = 1.65 that is consistent with a film density of rho
= 3.50 g/cm(3). Atomic force microscope images revealed that thr Al2O
3 films were exceptionally flat with a surface roughness of only +/-3
Angstrom (rms) after the deposition of similar to 270 Angstrom using 2
50 AB reaction cycles. Al2O3 films were also deposited inside the pens
of Anodise alumina membranes. Gas flux measurements for H-2 and N-2 w
ere consistent with a progressive pore reduction versus number of AB r
eaction cycles. Porosimetry measurements also showed that the original
pore diameter of similar to 220 Angstrom was reduced to similar to 13
0 Angstrom after 120 AB reaction cycles.