Hydrogenated Amorphous Silicon Deposited on the Asihtest Circuit for Radiation Detection

Radiation detectors were developed by depositing 20 μm thick hydrogenated amorphous silicon (a-Si:H) sensors directly on top of the so-called aSiHtest integrated circuit. This circuit was designed in a quarter micron CMOS technology as a global test circuit for this novel detector technology. The sensor leakage current turned out to be limiting the performance of the whole detector. Its detailed study is presented together with design techniques to reduce it. Direct detections of 10 to 50 keV electrons were demonstrated on integrated thin strip structures with a pitch down to 10 μm. Results are shown to understand the potential of the technology for ionizing radiation detection.