【Academic Forum】Particle and Photon Detector Research at RuđerBošković Institute (RBI)
Topic: Particle and Photon Detector Research at RuđerBošković Institute (RBI)
Lecturer: Professor Jaakko Härkönen, ERA chair at Ruđer Bošković Institute
Host: Professor Li Zheng
Time: 14:30, December 7 (Friday), 2018
Venue: Room 319, XTU No.2 Teaching Building
Professor Jaakko is a world-renowned expert in semiconductor detectors. He received his Ph.D. from Aalto University in 2001. He studied the fabrication of hadron radiation detectors based on Czochralski monocrystalline silicon at the Helsinki Institute of Physics between 2001 and 2012. He was a co-spokesperson of CERN RD39 Collaboration and convener for CERN RD50 Collaboration. In 2008, as the leader of the Finnish hardware group, he was responsible for the CMS experiment of the CERN LHC accelerator. In 2016, he has become President of ERA (European Research Area), whose goal was to establish a team and facilities dedicated to semiconductor radiation detectors at the Ruđer Bošković Institute (RBI). Professor Jaakko has published 500 research papers, of which about 100 are published in peer-reviewed journals. His research content mainly involves radiation-resistant reinforcement of semiconductor processing, radiation detectors, high-energy physical instruments and silicon detectors.
A design, fabrication process and characterization of photon detectors will be presented made of bulk Cadmium Telluride (CdTe) crystals, silicon drift detectors (SDD) and silicon detectors attached with conversion layer scintillator materials (SiS). The Si wafer and chip-scale CdTe detector processing with related interconnection processing was carried out in clean room premises of Micronova center in Espoo, Finland. Unlike Si wafers, CdTe processing must be carried out at the temperatures lower than 150◦C. Thus, we have developed a low temperature passivation layer processes of aluminum oxide (Al2O3) grown by Atomic Layer Deposition (ALD) method. The CdTe crystals the size of 10 × 10 × 0.5mm3 were patterned with proximity-contactless photo-lithography techniques. The detector properties were characterized by IV-CV, Transient Current Technique (TCT) and scanning micrometer precision proton beam methods. The experimental results were verified with TCAD simulations with appropriate defect and material parameters.