Gallium phosphate thin films: Synthesis and dielectric properties

Deposits of dielectric gallium phosphate thin films on silicon and gallium arsenide semiconductors have been obtained by pyrolysis of an aerosol produced by ultrasonic spraying ("pyrosol" process) and containing the organometallic precursors gallium acetylacetonate and tributyl phosphate, The composition and microstructure of the layers are discussed with respect to the experimental conditions, For this paper, electrical properties were also studied, Using the metal-insulator-semiconductor structure, the behavior of conductivity under direct current, capacitance, and dielectric loss was studied in terms of frequency, temperature, and chemical composition, The sites involved in the conduction process are structural defects directly related to the oxygen excess present in deposits which leads to the formation of M-O dangling bonds (M = Ga or P). (C) 1997 Academic Press.