Geothermal environmental exposure testing of encapsulant and device materials for harsh environment MEMS sensors

The development of harsh environment sensors for down hole geothermal well monitoring is needed to both optimize current production wells and to develop more accurate subsurface mapping to reduce the cost of well exploration. Exposure testing of encapsulant and device materials must be conducted within harsh environments to determine material survivability in the well bore environment. Mass change and sputter XPS chemical analysis were conducted on silicon, sapphire, silicon carbide (SiC), and aluminum nitride (AlN) after up to 100 hours of exposure testing in water at its critical point.