NPN bipolar phototransistors have been designed and fabricated on high-resistivity silicon substrates of different thicknesses, up to 800 µm. A technology featuring a double implant for the emitter allowed us to obtain a typical current gain of about 600. The device has been used to detect α particles from a 239Pu source, β particles from 90Sr and X-rays from 241Am using a simple experimental set-up, by directly connecting the detector to the scope. In the case of electrons, typical pulse heights of 100 mV have been observed, with pulse length of 50µs, measured on a load resistor in series to the emitter. The parameters driving the time performance have been measured, obtaining a good agreement with the electrical model of the device. We report on the functional characterization of the device with emphasis on the energy calibration and the electronic noise measurement.
High-gain bipolar phototransistor on high-resistivity silicon substrate: a new device for the detection of ionizing radiation
Boscardin, Maurizio;Dalla Betta, Gian Franco;Gregori, Paolo;Piemonte, Claudio;Rachevskaia, Irina;Ronchin, Sabina;Zorzi, Nicola
2004-01-01
Abstract
NPN bipolar phototransistors have been designed and fabricated on high-resistivity silicon substrates of different thicknesses, up to 800 µm. A technology featuring a double implant for the emitter allowed us to obtain a typical current gain of about 600. The device has been used to detect α particles from a 239Pu source, β particles from 90Sr and X-rays from 241Am using a simple experimental set-up, by directly connecting the detector to the scope. In the case of electrons, typical pulse heights of 100 mV have been observed, with pulse length of 50µs, measured on a load resistor in series to the emitter. The parameters driving the time performance have been measured, obtaining a good agreement with the electrical model of the device. We report on the functional characterization of the device with emphasis on the energy calibration and the electronic noise measurement.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
