Some of these devices include thermocouple gauges, Pirani gauges, and ionization gauges that measure pressure indirectly; capacitance nanometers, such as piezoelectric, piezoresistive parallel plate capacitive pressure sensors, are examples of devices that measure pressure directly. [0074] As shown in FIG. 4(a), fabrication begins with a 4 ??m KOH cavity recess 28 formed in a silicon substrate 30,