N4C3  Semiconductor Detectors 3

Thursday, Nov. 5  14:00-16:00  Golden West

Session Chair:  Grzegorz Deptuch, Fermilab, United States; Paul Barton, Lawrence Berkeley National Laboratory, United States

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(14:00) N4C3-1, High Speed Direct Electron Detector for Electronmicroscopy Based on DEPFET Pixel with Internal Signal Compression

R. H. Richter1, L. Andricek1, I. Dourki2, S. W. Epp2, K. Gärtner3, M. Hensel1, C. Koffmane1, J. Ninkovic1, D. R. J. Miller2, I. Peric4, G. Schaller1, M. Schnecke1, F. Schopper1, J. Treis1, A. Wassatsch1, F. Westermeier2, C. Zirr1

1Halbleiterlabor der Max-Planck-Gesellschaft, Munich, Germany
2Max-Planck-Institut für Struktur und Dynamik der Materie, Hamburg, Germany
3Weierstraß-Institut, Berlin, Germany
4Karlsruher Institut für Technologie, Karlsruhe, Germany
We present a high speed direct electron detector on thin silicon based on the DEPFET technology which is mainly intended for recording the dynamics of non-periodic (biological) samples in real space and real time. The sensor consists of 512x512 60µm pixel leading to an active area of about 3x3cm2. The sensor areas are thinned to 30µm or 50µm, respectively. They are currently in production at the MPG Semiconductor Lab. Monte Carlo simulations show that the Modulation Transfer Function demonstrate the expected imaging performance. To achieve a high dynamic range each DEPFET pixel is equipped with a signal compression stage. The signal response curve ensures single electron sensitivity as well as a noise below the Poisson statistics over the full dynamic range of up to 1.5 million electrons which corresponds to 300 primary 300keV electrons per pixel in a 50µm thick detector. The detector system is designed for a high speed operation of up to 80kHz frame rate at low power consumption of 1W in the sensor area. This is achieved by simultaneous readout of 4 pixel rows by a fast readout chip originally developed for Belle2. Control and readout chips as well as a signal pre-processor are placed on non thinned balcony structures surrounding the sensor matrix (all-silicon-module). The readout chips are directly flip-chipped to the silicon carrier. The detection area can be increased to 6x6cm² by arranging 4 neighboring modules with gaps in the active area of about 1.5mm. The cooling and mounting concept is briefly discussed as well as ways to cope with radiation damage.

(14:20) N4C3-2, DEPFET Based All-Silicon Multi-Chip Modules with Integrated Cooling Channels

L. Andricek1, J. Dingfelder2, N. Garcia3, C. Lacasta3, C. Marinas2, D. Markus2, J. Ninkovic1, E. Scheugenpflug1, G. Liemann1, M. A. Villarejo3, M. Vos3

1MPG Halbleiterlabor, Munich, Germany
2Bonn University, Bonn, Germany
3IFIC, Valencia, Spain
Future High Energy Physics experiments demand extremely transparent vertex detectors. The in-sensor amplification of the DEPFET APS makes it possible to build very thin sensors with an excellent signal/noise ratio for minimum ionizing particles – this has been shown with the latest ultra-thin DEPFET generation. However, the DEPFET requires additional read-out end steering ASICs which have to be connected to the sensor matrix. The interconnection, both on- and off-module, the mechanical support, and the cooling system are the largest contributions to the material budget. Based on the module development for the Belle II pixel detector PXD, we are presenting an all-silicon multi-chip module with the DEPFET sensor monolithically integrated in an actively cooled substrate for the auxiliary ASICs. The approach minimizes the number of assembly steps, the number of materials and hence the complications due to different CTEs and assembly inaccuracies. The combination of a highly specialized MOS technology with micro-mechanics and advanced high density interconnect technologies paves the way to an actively cooled self-supporting all-silicon pixel module with signal processing capabilities for high precision measurements with a minimum of material. The target application of this technology is high-precision vertex detection at future e+e- colliders. The paper will discuss the technology for the production of such modules and show results of the feasibility study based on thermo-mechanical samples.

(14:40) N4C3-3, Fabrication of ALD-Reinforced Pixel Radiation Detectors on Magnetic Czochralski Silicon Substrate

X. Wu1, M. Kainlauri1, H. Ronkainen1, S. Repo2, H. Savin2, J. Jakubek3, S. Vahanen4

1VTT, Espoo, Finland
2Aalto University, Espoo, Finland
3IEAP, Prague, Czech Republic
4Advacam Oy, Espoo, Finland
Interpixel isolation is a problem for any segmented p-type sensors. The commonly used approachs to improve the interpixel isolation is to introduce so-call p-spray and p-stop, which complicates the fabrication process and increase the likelihood of early breakdown. We used ALD (atomic layer deposition) to make alumia as interpixel dielectrics for n-implants on p-substrate. We fabricated the Medipix pixel sensors and diodes on the 150 mm p-type magnetic Czochralski silicon substrate. Process was optimized to avoid the thermal donors and maximize the negative charges existing at the interface between silicon and alumina. Preliminary results show a good uniformity across the wafer. Medipix pixel sensors are assembled on the Timpeix readout chips by low temperatue flip-chip bonding. Detectors are characterized with X-rays and radioactive sources and the spectroscopic results will be presented.

(15:00) N4C3-4, Study of antiproton annihilation in silicon with a hybrid pixel detector using the TimePix3 readout

H. Holmestad

University of Oslo, Oslo, Norway

On behalf of the AEgIS collaboration

The main goal of the AEgIS experiments is to measure the gravitational force for anti-hydrogen, testing Einstein's weak equivalence principle, which states that all bodies falls with the same acceleration, independently from their mass and composition. The measurement will be done using an anti-hydrogen beam sent trough a classical moire deflectometer. To measure the deflection of the beam from a straight path a position sensitive silicon detector followed by an emulsion detector and a scintillating fibre time-of-flight detector will be used.

We present here a study performed using a novel hybrid pixel detector, employing the Timepix3 readout chip to tag and spatially resolve antiproton annihilations in silicon. In autumn 2014 we performed a test-experimen on the secondary beam line of the AEgIS experiment, where a pulsed beam of anti-protons of energy 5.3 MeV was delivered from the Antiproton Decelerator of CERN accelerator complex. Taking advantage of the high spatial resolution, TOA capabilities and extended energy range of the Timepix3, this study investigates unique features of antiproton annihilation events in silicon. We are for the first time able to set clear criteria to characterize an antiproton annihilation using a silicon detector.

Further we will show how the annihilation point can be reconstructed using the tracks of the fragments from the annihilation. Using Technology Computer-Aided Design (TCAD) we are also able to investigate plasma effects in the silicon sensor, induced by heavily ionizing products of the annihilations.

(15:20) N4C3-5, Novel Small Pixel pnCCD Systems with High Speed Data Acquisition

J. Treis1, T. Haugh1, C. Koffmane1, J. Ninkovic1, R. H. Richter1, F. Schopper1, T. J. Selle1, A. Wassatsch1, M. Porro2

1MPG Semiconductor Laboratory, Munich, Germany
2Max-Planck-Institute for extraterrestrial Physics, Garching, Germany
Besides their use for spaceborn X-ray observatories, pnCCD devices increasingly find application in state-of-the-art instrumentation for ground-based experiments, e.g. X-ray diffraction pattern imaging, direct electron detection sensors for TEM, X-ray spectroscopy, and optical wavelength applications. Based on the principle of sidewards depletion, the devices are sensitive over the full depth and backside illuminated, providing for 100 % fill factor and excellent quantum efficiency over a wide range of x-ray energies down to very soft x-rays. The optimized entrance window permits the integration of a light shield or wavelength-specific ARC for optical applications. The tailored manufacturing technology provides for extremely low leakage current, and due to the integrated first readout FET, the devices have a very low readout capacitance. In combination with suitable VLSI integrated readout electronics, a readout noise of 2-3 e- ENC at processing times as short as 4 microseconds is achieved. Full column-parallel processing and split-frame readout provide for very high framerates. Due to their very high dynamic range, they are suitable for a wide variety of applications, from single photon resolved x-ray spectroscopy over imaging of intensive diffraction spots in XRD up to optical imaging in both high and low intensity applications. Recent advancements in technology and optimizations in structure and topology made significant improvements in terms of pixel size and an even higher readout speed possible. A large area split frame, frame-store pnCCD with a pixel size of 36 x 36 square micron will be presented. The device has 1024 x 1024 pixels in its storage area, connected to two frame-store areas with 512 x 1024 pixels each. The system allows for an unprecedented framerate of 400 Hz. The resulting data rate of 6.7 Gbyte / s is processed by a modular Gbit Ethernet-based DAQ system. Prototype results and first measurements on the large device are presented.

(15:40) N4C3-6, ACTIFIND - a Novel Technique for Trace Actinides Spectrometry Directly in Water Samples

O. R. Evrard1, Y. J. Anthoni1, C. Nebel2, C. Giese2, J. de Sanoit3, P. Bergonzo3, L. de Baerdemaeker1, N. Menaa1, R. Abou-Khalil4, M. Morichi4

1Silicon Production, Canberra Semiconductor nv, Olen, Belgium
2Fraunhofer-Institut für Angewandte Festkörperphysik (IAF), Freiburg, Germany
3Department of Metrology, Instrumentation and Information, Institut CEA LIST, Gif sur Yvette, France
4Corporate Research & Development, Areva, Paris, France
Vulnerability of drinking water distribution systems which would have major public health, economic and psychosocial consequences, has become a big concern to governmental agencies and water supply authorities. In case of an extremely alerting situation, such as Fukushima, the alpha emitters in water are probed on samples after very long chemical operations and time for the delivery of results extends over several days. The main objective of the ActiFind project is the realization of a high sensitivity alpha particles sensor working into water for the rapid detection and identification of traces of actinides at the 1 Bq/L level, after a short electro precipitation step. A thin BDD layer is deposited on a CANBERRA PIPS detector. Under low cathodic current density, nitrate reduction occurs and produces a layer of (OH-) at the BDD surface and solid actinides hydroxides are accumulated at the entrance window of the PIPS sensor. After deposition, the ActiFind sensor is directly connected to a spectrometry chain. The coupling of the system to an integrated microfluidic F.F.E. platform has been developed in order to render the system compatible with more complex aqueous solutions in real environments containing interfering ions or substances. Further extension of the system will explore the possibility to use it as a decontaminating system on a scale up basis. The ability to perform alpha spectrometry directly in liquid media at trace levels constitutes a real breakthrough. Bq/L range is reachable within 10 minutes, opening the field to the development of a portable system with low energy requirement, and enabling real time monitoring of media at risk. This new technology can be used in the analysis of water used for cleaning surfaces in fuel reprocessing plants, sampling of environmental water around waste storage facilities, analysis of water samples after a nuclear accident or in the Mining sector where water quality should be assessed in the surrounding area.