MECHANISM OF STABILIZING RUO2 TA2N DOUBLE-LAYER THIN-FILM RESISTORS/

RuO2/Ta2N double layer thin film resistors (D-TFR) may be tuned to pos sess a near-zero temperature coefficient of resistance (TCR) over a te mperature range of 100-400 degrees C. It has been shown by Auger elect ron spectroscopy (AES), electron spectroscopy for chemical analysis (E SCA), and cross-section transmission electron microscopy (XTEM) that a distinct layered structure along with an interfacial layer exists in the RuO2/Ta2N double layer thin film resistor. Chemically, the interfa cial layer is a ruthenium tantalum nitro-oxide, although there is a co mposition gradient for each element as proven by the AES depth profili ng. By inserting different intermediate barrier layers in between the two resistive layers, the effects of the ruthenium-rich interfacial la yer was deduced to be decisive in determining the temperature coeffici ent of resistance tuning process. This leads to an understanding of th e mechanism responsible for zero or near-zero TCR. (C) 1997 Published by Elsevier Science S.A.