Improved performance of GaAs radiation detectors
- Universita di Modena (Italy)
- Politecnico di Milano (Italy); and others
Gallium arsenide (GaAs) offers an attractive choice for room temperature X- and {gamma}-ray detectors. However performance of SI LEC bulk GaAs detectors is at present limited by the short carrier lifetime and by the diode breakdown occurring as soon as the electric field reaches the back ohmic contact. We have shown that ohmic contacts based on ion implantation allowed us to go far beyond the bias voltage necessary to achieve a fully active detector. However the conventional thermal treatments (850 {degrees}C, 30 s) required to anneal the damage induced by ion implantation strongly reduces the electron lifetime in the detector. Alenia has developed two improved processes (RA and RB) which avoid high temperature annealing and the consequent electron lifetime reduction. With the new detectors, in pixel (200x200 {mu}m{sup 2}) configuration, a charge collection efficiency (cce) of 90 % for 59.5 keV X-rays and a FWHM of 3.35 keV has been achieved at room temperature. These features, thickness, applied voltage, cce and FWRM are suitable for application of GaAs pixel detectors in medical imaging. Results obtained with of particles and X-rays at different temperatures and in a wide range of applied bias in detectors made with standard, implantated and improved processes are presented, compared and discussed.
- OSTI ID:
- 513006
- Report Number(s):
- CONF-961123-; TRN: 97:014066
- Resource Relation:
- Conference: Institute of Electrical and Electronic Engineers (IEEE) nuclear science symposium and medical imaging conference, Anaheim, CA (United States), 2-9 Nov 1996; Other Information: PBD: 1996; Related Information: Is Part Of 1996 IEEE nuclear science symposium - conference record. Volumes 1, 2 and 3; Del Guerra, A. [ed.]; PB: 2138 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Analysis of uniformity of as prepared and irradiated S.I. GaAs radiation detectors
Development of bulk GaAs room temperature radiation detectors