2012

Characterisation of Glasgow/CNM Double-Sided 3D Sensors
A. Mac Raighne, K. Akiba, J.P. Balbuena, R. Bates, M. van Beuzekom, J. Buytaert, P. Collins, M. Crossley, R. Dumps, L. Eklund, C. Fleta, A. Gallas, M. Gersabeck, V.V. Gligorov, M. John, M. Köhler, M. Lozano, D. Maneuski, U. Parzefall, D. Quirion, R. Plackett, C. Parkes, G. Pellegrini, E. Rodrigues, G. Stewart
Physics Procedia, Vol. 37, 2012, Pages 1016-1023
doi:10.1016/j.phpro.2012.02.445

Abstract: 3D detectors are proposed as an alternative to planar silicon technology to withstand the high radiation environments in planned future high energy physics experiments. Here we review the characterization of double-sided 3D detectors designed and built at CNM and the University of Glasgow. A non-irradiated sensor is characterized in a pion test-beamutilizing the Timepix telescope. The charge collection and detection efficiency across the unit pixel are shown. Area of inefficiency can be found at the columnar electrodes at perpendicular angles of beam incidence while the pixels are shown to be fully efficient at angles greater than ten degrees. A reduction in charge sharing compared to the planar technology is also demonstrated. Charge collection studies on irradiated devices with a Sr-90 source show higher charge collection efficiency for 3D over planar sensors at significantly lower applied bias. The sub-pixel response is probed by a micro-focused laser beam demonstrating areas of charge multiplication at high bias voltages.

Characterisation of micro-strip and pixel silicon detectors before and after hadron irradiation
P. P. Allport, K Ball, G Casse, V Chmill, D Forshaw, K Hadfield, A Pritchard, P Pool, I Tsurin
Journal of Instrumentation, 2012, Vol. 7, Issue 01, Article C01105
doi: 10.1088/1748-0221/7/01/C01105

Abstract: The use of segmented silicon detectors for tracking and vertexing in particle physics has grown substantially since their introduction in 1980. It is now anticipated that roughly 50,000 six inch wafers of high resistivity silicon will need to be processed into sensors to be deployed in the upgraded experiments in the future high luminosity LHC (HL-LHC) at CERN. These detectors will also face an extremely severe radiation environment, varying with distance from the interaction point. The volume of required sensors is large and their delivery is required during a relatively short time, demanding a high throughput from the chosen suppliers. The current situation internationally, in this highly specialist market, means that security of supply for large orders can therefore be an issue and bringing additional potential vendors into the field can only be an advantage. Semiconductor companies that could include planar sensors suitable for particle physics in their product lines will, however, need to prove their products meet all the stringent technical requirements. A semiconductor company with very widespread experience of producing science grade CCDs (including deep depletion devices) has adapted their CCD process to fabricate for the first time several wafers of pixel and micro-strip radiation hard sensors, suitable for future high energy physics experiments. The results of the pre-irradiation characterization of devices fabricated with different processing parameters and the measurements of charge collection properties after different hadron irradiation doses up to those anticipated for the (larger area) outer pixel layers at the high-luminosity LHC (HL-LHC) are presented and compared with results from more established particle physics suppliers.

Development of a novel 2D position-sensitive semiconductor detector concept
D. Bassignana, M Fernandez, R Jaramillo, M Lozano, F J Munoz, G Pellegrini, D Quirion, I Vila
Journal of Instrumentation, 2012, Vol. 7, Issue 04, Article C04008
doi: 10.1088/1748-0221/7/04/C04008

Abstract: A novel 2D position-sensitive semiconductor detector concept has been developed employing resistive electrodes in a single-sided silicon microstrip sensor. The resistive charge division method has been implemented reading out each strip at both ends, in order to get the second coordinate of an ionizing event along the strips length. Two generations of prototypes, with different layout, have been produced and characterized using a pulsed near infra-red laser. The feasibility of the resistive charge division method in silicon microstrip detectors has been demonstrated and the possibility of single-chip readout of the device has been investigated. Experimental data were compared with the theoretical expectations and the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The agreement between experimental and simulation results validates the developed simulation as a tool for the optimization of future sensor prototypes.

Charge collection measurements on slim-edge microstrip detectors
R. Mori, M. Bruzzi, M. Cartiglia, M. Christophersen, S. Ely, F. Martinez-McKinney, B. Phlips, H. Sadrozinski, V. Fadeyev
Journal of Instrumentation, 2012, Vol. 7, Issue 05, Article P05002
doi: 10.1088/1748-0221/7/05/P05002

Abstract: We have generated slim edges on manufactured silicon strip detectors by cleaving the non-active edge material and passivating the very smooth edge with a thin coat of silicon oxide. We report a comparison of I-V measurements and charge collection and noise measurements on two identical sensors, one with and one without slim edge treatment. The current voltage measurements of the entire sensor and individual strips indicate that the large current increase due to the treatment is confined to the guard ring, while the strips show essentially no increase in leakage currents. The noise on all strips, including the one adjacent to the slim edge, is not changed by the cut. The signal from a beta source before and after cutting is the same within 4%.

First investigation of a novel 2D position-sensitive semiconductor detector concept
D. Bassignana, M. Fernandez, R. Jaramillo, M. Lozano, F. J. Munoz, G. Pellegrini, D. Quirion, I. Vila
Journal of Instrumentation, 2012, vol. 7, Issue 02, Article P02005
doi.org/10.1088/1748-0221/7/02/P02005

Abstract: This paper presents a first study of the performance of a novel 2D position-sensitive microstrip detector, where the resistive charge division method was implemented by replacing the metallic electrodes with resistive electrodes made of polycrystalline silicon. A characterization of two proof-of-concept prototypes with different values of the electrode resistivity was carried out using a pulsed Near Infra-Red laser. The experimental data were compared with the electrical simulation of the sensor equivalent circuit coupled to simple electronics readout circuits. The good agreement between experimental and simulation results establishes the soundness of resistive charge division method in silicon microstrip sensors and validates the developed simulation as a tool for the optimization of future sensor prototypes. Spatial resolution in the strip length direction depends on the ionizing event position. The average value obtained from the protype analysis is close to 1.2% of the strip length for a 6 MIP signal.