Electrode metallization for high permittivity oxide RF thin film capacitors

The chemically inert materials Au and Pt failed to endure the high annealing temperature. Au became extremely rough and cracks appeared. Massive grain growth and adhesion loss occurred with Pt film. Mo electrode withstood the oxidizing ambient conditions with a sacrificial Si or Al-Ti diffusion barrier. Moderate increase in surface roughness was observed after the annealing due to oxidation. Also, thermally stable AlN, Si3N4, and SiO2 diffusion barriers were able to block oxygen from the Mo electrode.