Generic microelectronic smart sensor platform for detection of toxic, hazardous, and flammable gases

摘要

Extensive work has been performed in the past which demonstrates that various metal alloys can be used to detect different toxic, hazardous, and flammable gases. Work has been performed using Pd, Pt, Ir, PdNi, PdAg and Pt/Pd for detecting things such as Hydrogen, Hydrazine, Hydrogen Sulfide, Deuterium, Tritium, Ethanol and Hexane. Perhaps the most familiar is the use of Pd and PdNi for the detection of Hydrogen. These devices work by examining the effect of the gases on the material properties of the metal alloys. Two of the most common material properties examined in these sensors are the resistance of thin film resistors, and the flatband or threshold voltage shifts of MOS structures fabricated with a particular alloy as the gate material. While research into these sensing techniques has shown much promise, few manufacturable, fieldable devices have resulted. These sensing techniques are prone to drift problems due to temperature variations, and typically have large sample to sample variations in performance due to process control issues. Typically, these sensors require significant external instrumentation for measurement and control, making the systems large and expensive. Sandia National Laboratories has designed, fabricated and demonstrated complete functionality of a generic microelectronic based smart sensor platform intended to effectively exploit the research mentioned above into high performance, manufacturable, fieldable devices. This smart sensor platform technology fabricates 2 (mu)m CMOS digital and analog control electronics, sensing elements, and temperature control elements on the same silicon integrated circuit. Our initial demonstration of this technology incorporates PdNi as the sensing alloy for the detection of hydrogen.