We have been developing a novel radiation-tolerant n+-in-p silicon microstrip sensor for very high radiation environments, aiming for application in the high luminosity large hadron collider. The ...sensors are fabricated in 6in., p-type, float-zone wafers, where large-area strip sensor designs are laid out together with a number of miniature sensors. Radiation tolerance has been studied with ATLAS07 sensors and with independent structures. The ATLAS07 design was developed into new ATLAS12 designs. The ATLAS12A large-area sensor is made towards an axial strip sensor and the ATLAS12M towards a stereo strip sensor. New features to the ATLAS12 sensors are two dicing lines: standard edge space of 910μm and slim edge space of 450μm, a gated punch-through protection structure, and connection of orphan strips in a triangular corner of stereo strips. We report the design of the ATLAS12 layouts and initial measurements of the leakage current after dicing and the resistivity of the wafers.
The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to a fluence of 1×1016neq/cm2, exceeding the maximum of 1.6×1015neq/cm2 expected for the strip tracker ...during the high luminosity LHC (HL-LHC) period including a safety factor of 2. The ATLAS12, n+-on-p type sensor, which is fabricated by Hamamatsu Photonics (HPK) on float zone (FZ) substrates, is the latest barrel sensor prototype. The charge collection from the irradiated 1×1cm2 barrel test sensors has been evaluated systematically using penetrating β-rays and an Alibava readout system. The data obtained at different measurement sites are compared with each other and with the results obtained from the previous ATLAS07 design. The results are very consistent, in particular, when the deposit charge is normalized by the sensor's active thickness derived from the edge transient current technique (edge-TCT) measurements. The measurements obtained using β-rays are verified to be consistent with the measurements using an electron beam. The edge-TCT is also effective for evaluating the field profiles across the depth. The differences between the irradiated ATLAS07 and ATLAS12 samples have been examined along with the differences among the samples irradiated with different radiation sources: neutrons, protons, and pions. The studies of the bulk properties of the devices show that the devices can yield a sufficiently large signal for the expected fluence range in the HL-LHC, thereby acting as precision tracking sensors.
Punch-through protection of SSDs in beam accidents Sadrozinski, H.F.-W.; Betancourt, C.; Bielecki, A. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2011, Letnik:
658, Številka:
1
Journal Article
Recenzirano
We have tested the effectiveness of punch-through protection (PTP) structures on n-on-p AC-coupled Silicon strip detectors using pulses from an 1064
nm IR laser, which simulate beam accidents. The ...voltages on the strips are measured as a function of the bias voltage and compared with the results of DC
I–
V measurements, which are commonly used to characterize the PTP structures. We find that the PTP structures are only effective at very large currents (several mA), and clamp the strips to much larger voltages than assumed from the DC measurements. We also find that the finite resistance of the strip implant compromises the effectiveness of the PTP structures.
Evaluation of MCM-D technology for silicon strip detectors Eklund, L.; Affolder, A.; Casse, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Letnik:
623, Številka:
1
Journal Article
Recenzirano
Multi-chip Modules-Deposited (MCM-D) is a technology that can be applied to silicon strip modules and promises advantages in terms of integration complexity and material budget. This technology ...permits to integrate the front-end hybrid, pitch adaptor and wire bonds on the silicon sensor. The principle is to deposit alternating dielectric and metal layers directly on the silicon, where traces and vias are etched with high resolution to produce a PCB like structure.
This paper reports on a prototype MCM-D processing run of silicon strip wafers performed to evaluate suitability of the technology. This first run uses one dielectric layer, one metal layer, passivation and a final metallisation appropriate for wire-bonding. Connections are done through the first dielectric layer to the strips, the bias ring, bias resistors and guard rings. Hence the effects of the post-processing on the silicon sensor are evaluated measuring change in parameters such as I/V and C/V characteristics, inter-strip capacitance and resistance.
The ATLAS collaboration R&D group “Development of
n-in-
p Silico
n Sensors for very high radiation environment” has developed single-sided
p-type 9.75
cm×9.75
cm sensors with an
n-type readout strips ...having radiation tolerance against the 10
15 1-MeV neutron equivalent (n
eq)/cm
2 fluence expected in the Super Large Hadron Collider. The compiled results of an evaluation of the bulk and strip parameter characteristics of 19 new non-irradiated sensors manufactured by Hamamatsu Photonics are presented in this paper. It was verified in detail that the sensors comply with the technical specifications required before irradiation. The reverse bias voltage dependence of various parameters, frequency dependence of tested capacitances, and strip scans of more than 23,000 strips as a test of parameter uniformity and strip quality over the whole sensor area have been carried out at Stony Brook University, Cambridge University, University of Geneva, and Academy of Sciences of CR and Charles University in Prague. No openings, shorts, or pinholes were observed on all tested strips, confirming the high quality of sensors made by Hamamatsu Photonics.
Interstrip capacitance stabilization at low humidity Chilingarov, A.; Campbell, D.; Hughes, G.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2006, Letnik:
560, Številka:
1
Journal Article
Recenzirano
A long-term stabilisation of the interstrip capacitance after bias application is investigated with emphasis on low ambient humidity conditions. The measurements are made with ATLAS SCT microstrip ...detectors produced by Hamamatsu. It is shown that after the application of 150
V bias the interstrip capacitance is higher by 25–30% than its stable value. It is demonstrated that at low absolute humidity, mandatory for the SCT operation at subzero temperatures, the stabilisation time may be of order of months. Since the interstrip capacitance is one of the major sources of front-end electronics noise the results are important for the optimisation of operating conditions for the ATLAS SCT.
Different equivalent circuit diagrams are evaluated for the representation of the CV characteristics, measured with standard equipment, for a typical Si diode after heavy irradiation. A general ...approach is developed and several minimal models are analysed. A possible mechanism is proposed for the frequency dependence of the depletion voltage extracted from the CV measurements.
The dependence on measurement frequency and temperature of the depletion voltage extracted in the standard way from the
CV characteristics of heavily irradiated silicon detectors is studied, ...parameterised and fitted. A similar pattern of behaviour is observed for a wide range of analysed detectors. A formula is derived which allows correction of the depletion voltage from one frequency–temperature point to another.
A new method of carrier trapping time measurement Brodbeck, T.J; Chilingarov, A; Sloan, T ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2000, Letnik:
455, Številka:
3
Journal Article
Recenzirano
A new method of measuring carrier trapping time by a simple analysis of the current pulse shape is proposed and demonstrated for irradiated silicon detectors. This method which we call Exponentiated ...Charge Crossing (ECC) requires no knowledge of either the electric field profile in the detector or of the relation between the carrier drift velocity and the electric field. It is general enough to be valid not only for solid-state particle detectors but also for other devices such as some gaseous and liquid detectors. The results obtained by the proposed method are consistent with those obtained by an earlier method.
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