Studies of the dependence on oxidation thermal processes of effects on the electrical properties of silicon detectors by fast neutron radiation

High-resistivity silicon detectors along with MOS capacitors made on five silicon dioxides with different thermal conditions (975 degrees C to 1200 degrees C) have been exposed to fast neutron irradiation up to a fluence of a few times 10/sup 14/ n/cm/sup 2/. New measurement techniques such as capacitance-voltage (C-V) of MOS capacitors and current-voltage (I-V) of back-to-back diodes (p/sup +/-n/sup -/-p/sup +/ if n/sup -/ is not inverted to p) or resistors (p/sup +/-p-p/sup +/ if inverted) have been introduced in monitoring the possible type-inversion (n to p) under high neutron fluence. No type-inversion in the material underneath SiO/sub 2/ and the p/sup +/ contact has been observed so far for detectors made on the five oxides up to a neutron fluence of a few times 10/sup 13/ n/cm/sup 2/. However, it has been found that detectors made on higher-temperature oxides (T>or=1100 degrees C) exhibit less leakage current increase at high neutron fluence ( phi >or=10/sup 13/ n/cm/sup 2/).<
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