The radiation hardness of diodes fabricated on standard and diffusion-oxygenated float-zone, Czochralski and epitaxial silicon substrates has been compared after irradiation with
900
MeV
electrons up ...to a fluence of
2.1×10
15
e/
cm
2
. The variation of the effective dopant concentration, the current related damage constant
α and their annealing behavior, as well as the charge collection efficiency of the irradiated devices have been investigated.
Silicon test structures manufactured on different substrate materials (standard and oxygenated float-zone, magnetic and non-magnetic Czochralski, epitaxial silicon) have been irradiated with 900
MeV ...electrons up to a fluence of
6.1
×
10
15
e
/
cm
2
. Results are reported on the variation of the effective dopant concentration and of the leakage current density as a function of the electron fluence. The time evolution of the effective dopant concentration is also reported after thermal annealing cycles at
80
∘
C
.
We report on the design, manufacturing and first characterisation of pad diodes, test structures and microstrip detectors processed with high resistivity magnetic Czochralski (MCz) p- and n-type Si. ...The pre-irradiation study on newly processed microstrip detectors and test structures show a good overall quality of the processed wafers. After irradiation with 24
GeV/
c protons up to 4×10
14
cm
-2 the characterisation of n-on-p and p-on-n MCz Si sensors with the
C–
V method show a decrease of the full depletion voltage and no space charge sign inversion. Microscopic characterisation has been performed to study the role of thermal donors in Czochralski Si. No evidence of thermal donor activation was observed in n-type MCz Si detectors if contact sintering was performed at a temperature lower than 380
°C and the final passivation oxide was omitted.
n-p-n bipolar phototransistors have been designed and fabricated on high-resistivity silicon substrates. A technology featuring a double implant for the emitter allowed us to obtain a typical current ...gain of about 600. The device has been tested with /spl alpha/ particles from a /sup 239/Pu source, /spl beta/ particles from /sup 90/Sr, and X-rays from /sup 241/Am using a simple experimental setup, where the detector is directly connected to the oscilloscope. In the case of electrons, pulse heights of 100 mV have been observed, with pulse length of 50 /spl mu/s, measured on a load resistor in series to the emitter. The parameters driving the time performance have been measured, obtaining a good agreement with the electrical model of the device. We report on the functional characterization of the device, in particular the time response, the energy calibration, and the electronic noise measurement.
Several silicon devices, including test structures and double-sided microstrip detectors, have been irradiated with a 900 MeV electron beam. The irradiated test structures have been used to quantify ...bulk and surface damage effects caused by the incident particles. Bulk-type conversion from n to p-type has been observed to occur at fluences of order 10 14 cm -2 . For the damage constant α, a NIEL normalized value of about 3×10 -17 A/cm has been obtained. The results confirm that high-energy electrons, like neutrons and protons, are very effective in creating bulk damage in silicon.
Characterization of BJT-based particle detectors Piemonte, C.; Batignani, G.; Bettarini, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2004, Letnik:
535, Številka:
1
Journal Article
Recenzirano
We report on the static and dynamic behavior of BJT-based particle detectors realized on high-resistivity silicon. Several prototypes, featuring different doping profiles and geometries, have been ...fabricated at ITC-irst (Trento, Italy). These devices have been thoroughly characterized from the electrical viewpoint, and, in order to understand the fundamental parameters of the structure, device simulations have been performed, whose results are in very good agreement with experimental data. Preliminary functional measurements have been carried out by using a
109
Cd source excitation.
The radiation hardness of the AToM chips of the BaBar Silicon Vertex Tracker has been investigated by means of irradiation with photons from a /sup 60/Co source and 0.9 GeV electrons. The increase in ...noise and the decrease in gain of the amplifier have been measured as a function of the applied capacitive load and the absorbed dose. Different beam intensities have been used to study the effect of different dose rates to the AToM radiation damage. The chip digital functionalities have been tested up to a dose of 5.5 Mrads for the /sup 60/Co photons and 9 Mrads for the 0.9 GeV electrons. In addition a pedestal shift for the irradiated channels has been observed in the test with electrons but is not present in the irradiation with photons. This effect reproduces qualitatively the behavior observed since 2002 in the front-end electronics of the installed BaBar Silicon Vertex Tracker. After some investigation of the chip layout, this peculiar behavior could be associated to radiation damage in a well-identified component of the AToM. The results of the radiation tests are presented and used to extrapolate the lifetime of the installed detector and its performance in the next few years.
The effects of 900 MeV electron irradiation on different types of silicon substrates (standard and oxygenated float-zone, Czochralski, and epitaxial silicon) have been experimentally investigated. ...Irradiations up to a fluence of 2.1/spl times/10/sup 15/ e/cm/sup 2/ have been performed with the electron beam of the LINAC injector at the synchrotron light facility Elettra in Trieste (Italy). Irradiated devices have been electrically characterized by reverse I-V and C-V measurements. Substrate type inversion has been observed for standard and oxygenated float-zone but not for Czochralski and epitaxial devices. The effects of isothermal annealing cycles at 80/spl deg/C have also been studied, and the hardness factor of 900 MeV electrons, with respect to 1 MeV neutrons, has been experimentally estimated from the measurement of the reverse leakage current after annealing.
We have investigated the depletion voltage changes, leakage current increase and charge collection efficiency of a silicon microstrip detector identical to those used in the inner layers of the BABAR ...Silicon Vertex Tracker (SVT) after heavy nonuniform irradiation. A full SVT module with the front-end electronics connected has been irradiated with a 0.9 GeV electron beam up to a peak fluence of 3.5/spl times/10/sup 14/ e/sup -//cm/sup 2/, well beyond the level causing substrate type inversion. We have irradiated the silicon with a nonuniform profile having /spl sigma/=1.4 mm that simulates the conditions encountered in the BABAR experiment by the modules intersecting the horizontal machine plane. The position dependence of the charge collection properties and the depletion voltage have been investigated in detail using a 1060 nm LED and an innovative measuring technique based only on the digital output of the chip.
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