Process Development and Integration of Piezoelectric Aluminum Nitride Thin-Film for RF MEMS Applications

Abstract

ABSTRACTThe aluminum nitride (AlN) process was successfully developed for as high frequency thin-film for bulk acoustic resonator applications. Columnar AlN was deposited on p-type (100) silicon substrate at 300–500°C using pulse direct current (DC) sputtering technique. Argon to nitrogen ratio was optimized to achieve stoichiometry at higher deposition rates of about 1000 Å/min at 1–4 kW DC power. The XRD of as-deposited and annealed AlN film shows preferred (002) orientations. The dry etching process was developed and etching rate about 3200 Å/min was achieved using Cl based chemistry. Film composition analysis was done using AES technique and stoichiometry was achieved.