Silicon based timing detector development in Helsinki Tiina
Silicon based timing detector development in Helsinki Tiina Naaranoja, Jaakko Härkönen, Kenneth Österberg Helsinki Institute of Physics (HIP) Workshop on ``Timing detectors for PPS'', 19 November 2014 1
Outline Silicon strip sensor as timing detector On-going activity in Helsinki for Silicon timing detector Future activity 2
Silicon strip sensor as timing detector - *Radiation hardness of MCz-Si investigated up to 2× 1015 cm-2. - Si is relatively inexpensive detector can be replaceable. - When signal is capacitively coupled (AC), high leakage current does not connect into front-end electronics. - Strip segmentation can be optimized for fast rise time. Capacitance: C = ε× A/d , A = strip lenght × width, e. g. 1 cm × 20µm Test beam data of full size p-type MCz-Si Sensor with 768 strips, attached to CMS APV read-out and DAQ. Full signal from Non-irradiated reference sensor is 40 ADC *J. Härkönen et al. , 15 th RD 50 Workshop on Radiation hard semiconductor devices for very high luminosity colliders. http: //indico. cern. ch/event/65918/session/7/contribution/23/material/slides/0. pdf 3
On-going activity for Si timing detector - Joint project with HIP CMS and DESY CMS groups. - 20 6’’ p-type MCz-Si wafers will be processed strip and pixel sensors + relevant test structures. Processing will take place at Micronova center (Helsinki). http: //www. micronova. fi/ - Wafers have been thinned to 240µm thickness. - Surface current in n-on-p structure will be terminated by Atomic Layer Deposition (ALD) grown thin films with fixed negative oxide charge and/or p-stop/spray implantation. 4
On-going activity for Si timing detector 5
On-going activity for Si timing detector –Detectors currently being investigated - Processed in Micronova in 2012. - Jointly by HIP and VTT (Technical Research Center of Finland) - 6’’ n-type Mcz-Si - AC coupled strip sensors - Full depletion voltage 150 V 6
On-going activity for Si timing detector II - Transient Current Technique (TCT) measurements at HIP Detector laboratory. - 10 Me. V proton irradiation at University of Helsinki Accelerator Lab up to HL-LHC fluencies. - Irradiation includes inhomogenous radiation field to simulate CT-PPS conditions. - Measured rise time is limited by e. g: - Bias T needed for AC-coupling of oscilloscope - Pre-amplifier, bandwidth 2 GHz - Le. Croy, bandwidth 4 GHz 7
Future activity - Continue collaboration with CMS (Helsinki and Hamburg) to produce ultra-radhard Si-detectors - Irradiation and TCT measurement - Study effects of irradiation on signal rise time - Optimize strip segmentation and pitch for fast rise time - Limiting factor: Read-out electronics 8
Thank You! 9
Backup slide –Annealing of p-type MCz-Si C. Wiglesworth et al. , ”Charge collection annealing study of p-in-n silicon microstrip detectors”, 15 th RD 50 Workshop on Radiation hard semiconductor devices for very high luminosity colliders. http: //indico. cern. ch/event/65918/other-view? view=cdsagenda 10
Backup slide –TCT transients 11
References J. Härkönen, E. Tuominen, E. Tuovinen, P. Mehtälä, K. Lassila-Perini, V. Ovchinnikov, P. Heikkilä, M. Yli-Koski, L. Palmu, S. Kallijärvi et al, Processing of microstrip detectors on Czochralski grown high resistivity silicon substrates, Nuclear Instruments and Methods in Physics Research A 514 (2003) 173 -179. E. Tuominen J. Härkönen, E. Tuovinen, P. Luukka et al. , Radiation hardness of Cz-Si studied by 10 and 20 Me. V protons, IEEE Trans. Nucl. Sci. , 50 (2003) 1942. Z. Li, J. Härkönen, E. Tuovinen, P. Luukka et al. , Radiation hardness of high resistivity Cz-Si detectors after gamma, neutron and proton radiations, IEEE Trans. Nucl. Sci. , 51 (4) (2004) 1901 -1908. J. Härkönen, E. Tuovinen, E. Tuominen, P. Luukka, V. Eremin, E. Verbitskaya and Z. Li, Particle Detectors made of High-Resistivity Czochralski Silicon, Nuclear Instruments and Methods in Physics Research A 541 (2005) 202 -207. P. Luukka, J. Härkönen, T. Mäenpää, B. Betchart, S. Bhattacharya, S. Czellar, R. Demina, A. Dierlamm, Y. Gotra, M. Frey, F. Hartmann, V. Karimäki, T. Keutgen, S. Korjenevski, M. J. Kortelainen, T. Lampén, V. Lemaitre, M. Maksimow, O. Militaru, H. Moilanen, Test beam results of heavily irradiated magnetic Czochralski silicon (MCz-Si) strip detectors, Nuclear Instruments and Methods in Physics Research A 612 (2010) 497 -500. HIP CMS Upgrade: http: //research. hip. fi/hwp/cmsupg/ 12
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