Textured Aluminum Nitride Films Research Articles

Low-thickness high-quality aluminum nitride films for super high frequency solidly mounted resonators

We investigate the sputter growth of very thin aluminum nitride (AlN) films on iridium electrodes for electroacoustic devices operating in the super high frequency range. Superior crystal quality and low stress films with thicknesses as low as 160nm are achieved after a radio frequency plasma treatment of the iridium electrode followed by a two-step alternating current reactive magnetron sputtering of an aluminum target, which promotes better conditions for the nucleation of well textured AlN films in the very first stages of growth. Solidly mounted resonators tuned around 8GHz with effective electromechanical coupling factors of 5.8% and quality factors Q up to 900 are achieved.

Obtainment of textured films of aluminum nitride by thermochemical nitridation of sapphire

The possibility of obtaining textured aluminum nitride films by thermochemical nitridation of sapphire in the temperature range of 1200–1500°C in nitrogen atmosphere with the CO content from 0.1 to 5 vol % is shown. The diffusion mechanism of formation of the aluminum nitride film on the sapphire surface under the effect of the reducing medium is established.