Cerium oxide <mml:math display="inline"><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mtext>CeO</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math>(CeO2) solution was prepared by cerium(III) acetylacetonate hydrate, methanol, and acetic acid as the starting materials via the metallorganic decomposition (MOD) method. Postdeposition annealing was performed onto the MOD-derived <mml:math display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CeO</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>CeO2 films deposited onto n-type Si substrates at different temperatures (600, 800, and <mml:math display="inline"><mml:mrow><mml:mn>1000</mml:mn><mml:mo>°</mml:mo><mml:mi mathvariant="normal">C</mml:mi></mml:mrow></mml:math>1000°C ) under the flow of argon gas. A slow cooling rate was then accomplished for samples to cool down to room temperature. Four orientations [(111), (200), (220), and (311)] of <mml:math display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CeO</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>CeO2 films were revealed by X-ray diffraction analysis as well as <mml:math display="inline"><mml:mrow><mml:mi>α</mml:mi><mml:msub><mml:mrow><mml:mtext>-Ce</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>α-Ce2O3 and cerium silicate <mml:math display="inline"><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mtext>Ce</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Si</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math>(Ce2Si2O7) . Epitaxial-like behavior was shown in the sample annealed at <mml:math display="inline"><mml:mrow><mml:mn>600</mml:mn><mml:mo>°</mml:mo><mml:mi mathvariant="normal">C</mml:mi></mml:mrow></mml:math>600°C due to the (200)-oriented <mml:math display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CeO</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>CeO2 film, and the dominance of this plane ceased with the increase in annealing temperature. A negative voltage shift was observed in all of the samples, indicating that positive oxide charges were trapped in the oxide as a result of the presence of oxygen vacancies. An interface trap density was extracted from the capacitance–voltage measurement, and it was related to the current density–voltage characteristics of the investigated samples. The lowest density was perceived by the sample annealed at <mml:math display="inline"><mml:mrow><mml:mn>1000</mml:mn><mml:mo>°</mml:mo><mml:mi mathvariant="normal">C</mml:mi></mml:mrow></mml:math>1000°C due to the increment in the <mml:math display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>Ce</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mrow><mml:mtext>Si</mml:mtext></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mrow><mml:mn>7</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>Ce2Si2O7 layer, reduction in total interface trap density, and effective oxide charge.

Yttrium oxide has been successfully deposited on n-type 4H–SiC substrates using pulsed laser deposition. The effects of postdeposition annealing temperature (400, 500, and ) on the electrical properties of the gate oxide have been studied in comparison with the as-deposited sample. The sample annealed at possessed the highest dielectric breakdown field of at , resulting from the lowest interface trap density and total interface trap density. The Fowler–Nordheim tunneling mechanism has been investigated on all samples and the highest value of barrier height extracted between the semiconductor and oxide conduction band edges was 2.67 eV.

A mechanism regarding the redox reaction in lanthanum cerium oxide (La_xCe_yO_z) post-deposition annealed in reducing and oxidizing atmosphere was schematized and discussed in association with the presence of lanthanum as a substitutional cation. Analyses have been performed using X-ray diffraction, energy-filtered transmission electron microscopy, scanning transmission electron microscope-energy dispersive spectroscopy line scan, and capacitance–voltage measurements. The results showed the presence of an oxygen vacancy when La³⁺ was in its substitution site, while annihilation of oxygen vacancy was accompanied by a displacement of La³⁺ from the substitutional site to the interstitial site via a kick-out mechanism prior to its disappearance from the CeO₂.