A Method of Reducing Cost in the Production of High Stability Thin-Film RC Networks

Several methods of producing RC thin-film hybrid integrated circuits have been described in the literature. A specific method presented in a paper by Duff et al. at the 1978 Electronic Component Conference utilized alpha tantalum to form the capacitors and tantalum nitride for the resistors to produce a high stability RC network. A significant modification of this process which allows for a reduction in cost while retaining the stable properties of alpha tantalum capacitors is described herein. Consideration in developing this method centered on quantifying the thermal effects on the capacitors and evaluating a modified counterelectrode metalization. The process developed, which is easily adaptable to large-scale manufacturing, is simplified by reducing both the number of metal depositions and photolithographic steps. The capacitor properties and long-term reliability are shown to be at least equivalent to those of capacitors made using other processes.