Low Temperature Technology Options For Integrated High Density Capacitors

摘要

In recent years, integrated high-density capacitors have gained a lot of interest for RF and Mixed Signal IC applications. In this paper, we discuss technological options for integrated capacitors with capacitance densities up to 30fF/μm{sup}2. The capacitive structures where realized with dielectric materials such as Bi-Ta-O, Sr-Ta-O or Ta{sub}2O{sub}5. The Bi-Ta-O and Sr-Ta-O were deposited by means of Metal Organic Chemical Vapor Deposition (MOCVD) at 360°C. Films with densities up to 30fF/μm{sup}2 were obtained, the leakage current of the structures remained below 3·10{sup}(-8) A/cm{sup}2 at 3V for densities below 10 fF/μm{sup}2. In parallel, a dual dielectric layer process, with maximum fabrication temperature of 250°C, based on the anodic growth of Ta{sub}2O{sub}5 was yielding devices with leakage current below 1·10{sup}(-9) A/cm{sup}2 at 3V for 9.5 fF/μm{sup}2 capacitance density.