Piezoresistive pressure sensors based on SMART CUT® SOI wafer have been developed, which can be
used in extreme high temperature environments. It has been demonstrated that the resistance value of a
heavily doped thin film (∼0.34m) resistor increases monotonically with temperature up to 600 ◦C. This
is much higher than the maximum temperature of 330 ◦C normally shown in bulk silicon resistors. An
analytical model is developed to explain howto extend the maximum operating temperature range based
on doping effects and minority-carrier exclusion effects. Two types of packaging have been developed for
different applications; one is for low pressure, high accuracy application, the other is for high pressure,
high temperature application. The former is fully characterized across the range of 0.5–25 psi and −55
to 300 ◦C and the latter is calibrated across the range of 16–600 psi and −55 to 500 ◦C. A digitized curve
fitting technique is used to calibrate the sensors by use of on-chip temperature signals. After curve fitting,
the accuracy is