Silicon PIN radiation detectors with on-chip front-end junction field effect transistors

We report on the latest results obtained from the development of a fabrication technology for PIN radiation detectors with on-chip front-end junction field effect transistors (JFETs) integrated on high-resistivity, FZ silicon. P-doped polysilicon back-side gettering prevented carrier lifetime degradation in spite of the relatively high thermal budget characterizing the fabrication process, allowing very low leakage currents (≃1 nA/cm2 at full depletion) to be obtained. Results from JFETs electrical characterization are presented, showing high transconductance and output resistance values as well as low gate currents and input capacitance. JFETs performance is not affected by the high reverse-bias voltage required for detector operation, making these devices suitable for the fabrication of monolithical preamplifiers integrated on the detector chip.