Hydrogen Profiles of Anodic Aluminum Oxide Films

Abstract

The 15N hydrogen profiling technique is used to measure hydrogen concentration profiles in a variety of Al2O3 films including amorphous anodic barrier films grown in different electrolytes, pseudoboehmite, and composite oxide films grown by reaction with boiling water followed by anodic oxidation. Hydrogen profiles of the composite oxide films confirm that the “relaxation” which causes a large loss in field strength results from penetration of water deep into the oxide film. Comparison of our results with those obtained by SIMS is made where the SIMS data are available.

Mobility of lithium ions in anodic alumina formed on an Al–Li alloy

“…Thus, the presence of OH À ions in the ®lm is negligible, which is consistent with previous studies of amorphous barrier ®lms grown on high purity aluminium [14]; however, increased amounts of hydrogen are reported for ®lms grown under condition in which surface hydration may occur [14,15]. It is possible that the small amounts of hydrogen detected in the present ®lms are associated with modi®ed ®lm material formed at¯aw sites in the ®lms.…”

Nonlinear relaxational polarization in aluminum oxide

“…Corresponding extracted asymmetries are 0.042, 0.061 and 0.075 eV. Note as reported in [13] the hydrogen concentration in alumina can be raised up to 5×10 28 m -3 . The results of Figure 19 can be closely compared with Figure 8b.…”

“…The possible candidates for m are oxygen, aluminum, the electron and the proton. The existence of protons in Al 2 O 3 films was proved by a radioactive method [13]. Here incorporation of protons in the thin film probably happens due to the reaction of depositing materials with residual gases e. g. H 2 molecules as explained above.…”

“…10 min after stopping the deposition the hydrogen intensity (the dotted curve) drops close to that of the background pressure (the solid curve). In [13] it is demonstrated that the concentration of atomic hydrogen in Al 2 O 3 can be raised up to 5×10 28 m -3 by means of simple water treatments of the samples. The Al 2 O 3 atomic number density is 2.3×10 28 m -3 .…”

Improving dielectric performance in anodic aluminum oxide via detection and passivation of defect states

“…The oxide film can therefore be modeled as a p-i-n junction; 9,10 defect states responsible for doping could be removed, however, by annealing at temperatures in the 300-450 C range, 9,11 which enables annihilation of trap sites 11 or possibly desorption of water or electrolyte species. 12,13 Understanding and control of defect sites in oxides may, therefore, enable tailoring of their dielectric properties. In this Letter, we quantify the defect density of anodic alumina films as a function of annealing temperature, and demonstrate a striking improvement of their dielectric performance in both the solid state and in the oxide/electrolyte configurations upon annealing.…”