Solution based prompt inorganic condensation and atomic layer deposition of Al2O3 films: A side-by-side comparison

A comparison was made of Al2O3 films deposited on Si via prompt inorganic condensation (PIC) and atomic layer deposition (ALD). Current–voltage measurements as a function of annealing temperature indicate that the solution-processed PIC films, annealed at 500 °C, exhibit lower leakage and roughly equivalent breakdown strength in comparison to ALD films. PIC films are less dense than as-deposited ALD films and capacitance–voltage measurements indicate a lower relative dielectric constant. On the basis of x-ray photoelectron spectroscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy, it is found that the 500 °C anneal results in the formation of a ∼6 nm thick interfacial SiO2 layer at the Si interface. This SiO2 interfacial layer significantly affects the electrical performance of PIC Al2O3 films deposited on Si.