Stoichiometric and pure Al2O3 gate dielectric films were grown on n-type 4H-SiC by a thermal atomic layer deposition process. The electrical properties of both amorphous and epitaxial Al2O3 films were studied by capacitance-voltage and current-voltage measurements of metal-oxide-semiconductor capacitors. A dielectric constant of 9 and a flatband voltage shift of +1.3V were determined. A leakage current density of 10−3A∕cm2 at 8MV∕cm was obtained for the amorphous Al2O3 films, lower than that of any high-κ gate oxide on 4H-SiC reported to date. A Fowler-Nordheim tunneling mechanism was used to determine an Al2O3∕4H-SiC barrier height of 1.58eV. Higher leakage current was obtained for the epitaxial γ-Al2O3 films, likely due to grain boundary conduction.

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Atomic layer deposition (ALD) was used to control the stoichiometry of thin lithium aluminosilicate films, thereby enabling crystallization into the ion-conducting βeucryptite LiAlSiO 4 phase. The rapid thermal annealed ALD film developed a well-defined epitaxial relationship to the silicon substrate: β-LiAlSiO 4 (12̅ 10)||Si (100) and β-LiAlSiO 4 (101̅ 0)||Si (001). The extrapolated room temperature ionic conductivity was found to be 1.2 × 10 −7 S/cm in the [12̅ 10] direction. Because of the unique 1-D channel along the c axis of β-LiAlSiO 4 , the epitaxial thin film has the potential to facilitate ionic transport if oriented with the c axis normal to the electrode surface, making it a promising electrolyte material for three-dimensional lithium-ion microbatteries.

The incubation time during atomic layer deposition (ALD) of lead oxide, zirconium oxide, and titanium oxide on each other was quantified in order to precisely control the composition of lead zirconate titanate (PZT). The desired stoichiometry of Pb:Zr:Ti¼2:1:1, which yields the desired ferroelectricity, was found to depend strongly on the ALD sequence, the substrate of choice, as well as the postdeposition annealing temperature. With the desired stoichiometry, the ferroelectric and piezoelectric properties of the PZT films were validated by polarization-voltage hysteresis loop and piezoresponse force microscopy, respectively, demonstrating that ALD method is a viable technique for ultra thin ferroelectric films for device applications.

An ordered Co/ Al 2 O 3 core-shell nanocrystal ͑NC͒ nonvolatile memory device was fabricated. Self-assembled diblock copolymer process aligned the NCs with uniform size. Co/ Al 2 O 3 core-shell NCs were formed using atomic layer deposition of Al 2 O 3 before and after the ordered Co NC formation. Compared to Co NC memory, Co/ Al 2 O 3 core-shell NC memory shows improved retention performance without sacrificing writing and erasing speeds.

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Hafnium aluminate thin films were synthesized by atomic layer deposition (ALD) to assess the effect of aluminum oxide incorporation on the dielectric/Ge interfacial properties. In these HfxAlyOz thin films, the Hf to Al cation ratio was effectively controlled by changing the ratio of hafnium oxide to aluminum oxide ALD cycles, while their short range order was changed upon increasing aluminum oxide incorporation, as observed by extended x-ray absorption fine structure analysis. The incorporation of aluminum oxide was shown to improve the electrical characteristics of hafnium oxide/Ge devices, including lower interface state densities and leakage current densities.