The niobium doping effects on resistance degradation of strontium titanatethin film capacitors

The rate of resistance degradation of thin (< 450 Angstrom) niobium-doped s trontium titanate polycrystalline films with platinum top electrodes and ir idium bottom electrodes was investigated as a function of direct current (d c) voltages, temperature, Nb atomic fractions [Sr(Ti1-xNbx)O3+y, x=0, 0.001 , 0.01, and 0.05, respectively], and capacitor areas (from 2.50x10(-5) to 2 .91x10(-3) cm(2)). It was found that by increasing the amount of niobium, t he resistance degradation rates were greatly reduced, but the leakage curre nts increased. Also, the degradation rates seemed fairly independent of the areas of the devices. (C) 1999 American Institute of Physics. [S0003-6951( 99)04836-6].