Low temperature technology options for integrated high density capacitors

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 30 fF/mu m(2). The capacitive structures where realized with dielectric materials such as Bi-Ta-O, Sr-Ta-O or Ta2O5. The Bi-Ta-O and Sr-Ta-O were deposited by means of Metal Organic Chemical Vapor Deposition (MOCVD) at 360 degrees C. Films with densities up to 30 fF/mu m(2) were obtained, the leakage current of the structures remained below 3.10(-8) A/cm(2) at 3V for densities below 10 fF/mu m(2). In parallel, a dual dielectric layer process, with maximum fabrication temperature of 250 degrees C, based on the anodic growth of Ta2O5 was yielding devices with leakage current below 1.10(-9) A/cm(2) at 3V for 9.5 fF/mu m(2) capacitance density.