A5105463064- Particle Detector Development and Performance
- Silicon and Solar Cell Technologies
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Semiconductor materials and devices
- CCD and CMOS Imaging Sensors
- Quantum Chromodynamics and Particle Interactions
- Semiconductor materials and interfaces
- Thin-Film Transistor Technologies
- Radiation Effects in Electronics
- Silicon Nanostructures and Photoluminescence
- Advanced Radiotherapy Techniques
- Nanowire Synthesis and Applications
- Nuclear Physics and Applications
- Advanced Semiconductor Detectors and Materials
- Advancements in Semiconductor Devices and Circuit Design
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Muon and positron interactions and applications
- Radiation Effects and Dosimetry
- Electronic and Structural Properties of Oxides
- Integrated Circuits and Semiconductor Failure Analysis
- Parallel Computing and Optimization Techniques
- Copper Interconnects and Reliability
University of Helsinki
2004-2023
Helsinki Institute of Physics
2009-2021
Rudjer Boskovic Institute
2020-2021
European Organization for Nuclear Research
2006
For the planned luminosity upgrade of CERN LHC to sLHC new radiation hard technologies for tracking detectors are investigated. Corresponding increase, dose will be approximately a factor ten higher than currently installed in experiments. One option tolerant 3D silicon with columnar electrodes penetrating into bulk. This article reports results beam test measurements performed 3D-DDTC (Double-Sided, Double Type Column) strip detectors, where columns do not pass through detector completely....
After low dose electron irradiation, annealing kinetics of divacancy-oxygen $({\mathrm{V}}_{2}\mathrm{O})$ and vacancy-oxygen (VO) complexes in carbon-lean $n$-type magnetic Czochralski (MCZ) diffusion-oxygenated float-zone (DOFZ) Si samples has been studied detail. The were $n$ type with a phosphorus doping concentration the ${10}^{12}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ range, analysis was conducted by means deep-level transient spectroscopy (DLTS). An exponential...
A quantitative study about the thermal activation of oxygen related donors in high resistivity p-type magnetic Czochralski silicon has been carried out. Thermal donor formation performed through isothermal annealing at 430°C up to a total time 120min. Space charge density after each step measured by transient current technique. The localized energy levels double (TD) have observed and studied details thermally stimulated currents (TSCs) range 10–70K, energies E effective cross sections σ...
The planned luminosity upgrade of the CERN LHC to super (sLHC) requires investigation new radiation hard tracking detectors. Compared LHC, detectors must withstand a 5–10 times higher fluence. Promising options are planar silicon with n-side readout and in 3D technology, where columnar electrodes etched into substrate. This article presents beam test measurements performed n-in-p strip were irradiated different fluences, maximum fluence was <formula formulatype="inline"...
Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of LHC beam loss monitoring system.The would be installed immediate proximity superconducting coils triplet magnets.We present here results situ irradiation test silicon using 23 GeV protons while keeping at temperature 1.9 K. Red laser (630 nm) Transient Current Technique DC current measurements were used to study pulse response collected charge irradiated maximum radiation...
A deep level transient spectroscopy (DLTS) study of electrically active defects in electron irradiated silicon detectors has been performed. Two types materials have studied and compared: carbon-lean magnetic Czochralski (MCZ-) Si, high purity, diffusion oxygenated float-zone (DOFZ-) Si. In both we observed an earlier reported shift position peaks associated with the divacancy (V2) at 250–325 °C, indicating a gradual transition from V2 to divacancy–oxygen complex (V2O). Heat treatments...
Tracking detectors to be used in the future high-luminosity particle physics experiments have simultaneously radiation hard and cost ecient.Magnetic Czochralski silicon wafers can grown with suciently high resistivity (several kΩ cm) well-controlled oxygen concentration.Signicant research development activity aiming develop made of magnetic has been ongoing during past decade.Beam test results presented this paper show that n-type strip operated acceptable signal-to-noise ratio at least up a...
Positron annihilation in solid-state matter can be utilized to detect and identify open-volume defects. The momentum distribution of the radiation is an important observable positron-based measurements reveal information on chemical surroundings defect sites. In this paper, we present a variational quantum Monte Carlo method for simulation densities annihilating electron-positron pairs semiconductors insulators. We study finite-size effects, effects lattice vibrations, different levels trial...
A new approach to improve Si detector radiation hardness/tolerance, termed as DRIVE (Detector Recovery/Improvement Via Elevated-temperature-annealing), has been realized by annealing of oxygen-rich (magnetic Czochralski), proton-irradiated detectors (with negative space charge before annealing) at medium temperature for a few hours. The proved lead the dramatic decrease in leakage current, concentration, and an eventual sign inversion from positive. Defect studies have shown significant...