Laser-Patterned Ta2N Resistors for Thin Film Circuits

A process using laser-machining techniques has been · developed for patterning the detailed features of thin film Ta
2
N resistors on as-fired ceramic substrates. Laser machining serpentine patterns in etched blocks of resistor film reduces line and space widths below those practical with off-contact photolithography and wet etching. The resulting area savings varies as a function of resistance from a factor of 1.5 to about five. The laser-patterned resistor is designed to retain the high stability of conventionally patterned resistors and to allow its incorporation into thin film resistorcapacitor (RC) circuits. Compatibility with standard RC processing has been established. The results of thermal-aging studies have been extrapolated to predict a resistance drift of less than 0.1 percent over 20 years at 65°C.