Analysis of Al 2 O 3 Atomic Layer Deposition on ZrO 2 Nanoparticles in a Rotary Reactor

Al 2 O 3 atomic layer deposition (ALD) is analyzed on ZrO 2 nanoparticles in a rotary reactor. This rotary reactor allows for static exposures and efficiently utilizes the reactants for ALD on high surface area nanoparticles. The Al 2 O 3 ALD is performed using exposures to Al(CH 3 ) 3 and H 2 O reactants. The pressure transients during these exposures are examined using a sequence of reactant micropulses. These micropulses are less than the required exposures for the ALD surface chemistry to reach completion. The pressure transients during identical sequential Al(CH 3 ) 3 and H 2 O micropulses change as the surface chemistry progresses to completion. These pressure transients allow the required saturation reactant exposure to be determined to maximize reactant usage. The ZrO 2 nanoparticles are coated using various numbers of Al(CH 3 ) 3 and H 2 O reactant exposures. The Al 2 O 3 ALD‐coated ZrO 2 nanoparticles are subsequently analyzed using a number of techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Auger electron spectroscopy (AES), scanning AES (SAES), and X‐ray photoelectron spectroscopy (XPS). The TEM images reveal very conformal Al 2 O 3 ALD on the ZrO 2 nanoparticles. The Al 2 O 3 ALD thicknesses versus number of Al(CH 3 ) 3 and H 2 O reactant exposures yielded an Al 2 O 3 ALD growth rate of 2.0 Å per reactant cycle. The AES and XPS results are consistent with an Al 2 O 3 ALD film that completely and conformally covered the underlying ZrO 2 nanoparticle. The SAES measurements show that the Al 2 O 3 ALD films are continuous and homogeneous on the ZrO 2 nanoparticles. These results demonstrate that a rotary reactor can successfully perform ALD with high reactant efficiency on high surface area nanoparticles. Al 2 O 3 ALD has been analyzed on ZrO 2 nanoparticles in a rotary reactor. Pressure transients during a sequence of reactant micropulses determine the required exposure for the ALD surface chemistry to reach completion. Knowing the required exposure produces high reactant efficiency for ALD on high surface area nanoparticles. Analysis of the ALD‐coated ZrO 2 nanoparticles with SEM, TEM, AES, scanning AES and XPS is consistent with continuous and conformal Al 2 O 3 ALD films.