TANTALUM THIN FILM CAPACITORS WITH VARIOUS TYPES OF COUNTERELECTRODES.

Capacitors have been prepared from N//2-doped, triode sputtered Tantalum films by conventional anodization and photolithographic techniques. NiCr-Au, Ta-Ti-Pd-Au, Ta-NiCr-Pd-Au have been used as counterelectrode materials and a. c. and d. c. properties of the capacitors have been compared. It has been found that a doped Ta thin layer deposited by sputtering between the dielectric and the top electrode does not negatively affect the capacitors characteristics; moreover, a thermal treatment at temperatures as high as 350 degree C can be tolerated. If the Ta film deposited after the dielectric formation is used for resistive elements, a fully compatible R-C process is obtained which requires only two vacuum deposition cycles and four photolithographic steps.