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Abstract: 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 (∼0.34μm) 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 how to 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 0.5–25psi and −55 to 300°C and the latter is calibrated across the range of 16–600psi 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 <0.05% F.S. for the first type of the pressure sensor and <0.25% F.S. for the second type of the pressure sensor. A very low pressure hysteresis (<0.1% FS) at 500°C indicates that the single crystal silicon diaphragm is capable of operating at very high temperature without creep or plastic deformation. [Copyright &y& Elsevier]

• Avalanche characteristics for p+-Si/n-ZnO heterojunction photodetector were studied. • The p+-Si/n-ZnO photodetector can well perform as a linear and fast response photodetector with good repeatability. • Neutron irradiation effects on sputtered ZnO film and p+-Si/n-ZnO photodetector were experimentally studied. The photo detection properties under large reverse bias voltage and neutron irradiation effects of the p+-Si/n-ZnO photodetector were investigated. Intrinsic defects, V O, V Zn , and O i, were observed in the non-irradiated ZnO film from the photoluminescence spectroscopy. The neutron induced defects in the neutron irradiated ZnO film reacted with the V Zn , O i and grain boundary defects resulting in the degradation of mid band emissions. The p+-Si/n-ZnO heterojunction shows a rectifying factor of >1000 at 300 K under ±1.5 V and an avalanche breakdown voltage of ∼13 V. The impact ionization process is taken place in the p+-Si region revealed from the numerical calculation of the breakdown voltage of the p+-Si/n-ZnO heterojunction. The device can well perform as a linear and fast response photodetector with good repeatability. When operating under large reverse bias voltage, the p+-Si/n-ZnO can also act as an avalanching photodiode with the avalanche gain of ∼ 30. The p+-Si/n-ZnO detector continues to be operative as an avalanche photodiode as well after neutron irradiation with the fluence of 1015 n/cm2 unless the gain degenerating to ∼10, indicating the good neutron tolerance of the p+-Si/n-ZnO photodetector. [ABSTRACT FROM AUTHOR]