Device Geometry Consideration of CVD Diamond Alpha-particle Detectors

摘要

In this paper, two types of detectors, one with a coplanar and the other with a sandwich geometry using an identical CVD diamond film, were fabricated in order to investigate the effects of the film microstructure on the performance of diamond film ?-particle detectors. An average charge collection efficiency of 42.9% for the coplanar structure and of 37.4% for the sandwich structure detectors was obtained, respectively. The different counts, collection efficiencies and photocurrents of the two types of detectors mainly resulted from the different micro-structural features between the final growth side and the nucleation side of the diamond film. Under a particle irradiation the detector with sandwich geometry had a similar trend on energy resolution with coplanar geometry under different applied electric field. A good energy resolution of 1.1% was obtained for both detectors.