Development of a Novel Resistor System for Nitrogen Firing Applications

A novel resistor system compatible with both a copper conductor and a low K dielectric formulation has been under development as a result of an increased interest in such a system. In this paper, which is essentially a current progress report, the capabilities of this system as they have progressed to date are defined. A processing study addressing the effect of peak firing temperature on resultant resistor properties yielded superior performance at 850°C. The properties monitored include sheet resistivity, hot and cold TCR, TCR, VCR, and aspect ratio tracking. Laser trim drift data and long term drift data as a function of elevated temperature and humidity are presented for unencapsulated and encapsulated trimmed resistors. Topographic and cross-sectional microstructural features of this system were studied using backscattered electron imaging (BEI) with a scanning electron microscope (SEM) and X-ray microanalysis (XRM).