Improvements in the dielectric properties of aluminium nitride through passivation

Poly-crystalline and amorphous AlN is susceptible to oxidation via the large surface area presented by intergranular voids and vacancies. Here we present measurements of the electrical properties of metal-insulator-metal AlN based structures that show marked improvement in dielectric breakdown and I-V characteristics following the application of various passivation strategies that prevent surface oxidation. Breakdown fields of >100 MV/m have been achieved and up to four orders of magnitude reduction in current density. Frequency dependent dielectric constant and dielectric loss measurements are also presented.