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 fab rication technology for PIN radiation detectors with on-chip front-end junction field effect transistors (JFETs) integrated on high-resistiv ity, FZ silicon. P-doped polysilicon back-side gettering prevented car rier lifetime degradation in spite of the relatively high thermal budg et characterizing the fabrication process, allowing very low leakage c urrents (similar or equal to 1nA/cm(2) at full depletion) to be obtain ed. Results from JFETs electrical characterization are presented, show ing 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, mak ing these devices suitable for the fabrication of monolithical preampl ifiers integrated on the detector chip. (C) 1998 Elsevier Science B.V. All rights reserved.