Study of a CdTe high-energy radiation imaging device fabrication by excimer laser processing

摘要

CdTe based high-energy radiation imaging devices with high-energy resolution with room temperature operation, were fabricated by excimer laser low-temperature processing. A time-resolved reflectivity (TRR) in-situ measurement was carried out for CdTe transitions in order to identify clearly the laser-induced melting threshold of CdTe semiconductor. The threshold was estimated to be about a pulse energy of 50mJ/cm2. The CdTe M--n diode structures were prepared by excimer laser processing and the diode showed good diode I-V characteristics. The reverse current was very low less then 1nA at -100 V as an operation bias, and the CdTe detectors showed good and uniform spectra measurement characteristics. They were integrated with ASIC chips for signal processing as an imaging device unit. The imaging device unit could capture energy resolution of gamma-ray images distinguished by radiation photon energy. The all pixel has within 4.4 keV of FWHM at 122 keV from a Co-57 radioisotope source at room-temperature operation. The intensities of the peak were also very uniform in the device.