Effect of Proton Irradiation Induced Defects on 4H-SiC Schottky Diode X-Ray Detectors

2011 ◽  
Vol 679-680 ◽  
pp. 547-550
Author(s):  
Rupert C. Stevens ◽  
Konstantin Vassilevski ◽  
John E. Lees ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall

Detectors capable of withstanding high radiation environments for prolonged periods of exposure are essential for the monitoring of nuclear power stations and nuclear waste as well as for space exploration. Schottky diode X-ray detectors were exposed to high dose proton irradiation (1013 cm-2, 50 MeV) and changes in the detection resolution (spectroscopic full width half-maximum) have been observed. Using Deep Level Transient Spectroscopy (DLTS) and the degradation of the electrical characteristics of the diode, we have shown that radiation induced traps located in the upper half of the bandgap have reduced the concentration of carriers.

1993 ◽  
Vol 325 ◽  
Author(s):  
George C. Rybicki ◽  
Wendell S. Williams

AbstractDeep Level Transient Spectroscopy (DLTS) was used to study the defects introduced in Zn and Cd doped Schottky barrier diodes by 2 MeV proton irradiation. The defects H3, H4 and H5 were observed in lightly Zn doped InP, while only the defects H3 and H5 were observed in more heavily Zn doped and Cd doped InP. The defect activation energies and capture cross sections did not vary between the Zn and Cd doped InP.The concentration of the radiation induced defects was also measured. The introduction rate of the defect H4 in the lightly Zn doped InP and the introduction rate of the defect H3 in the heavily Zn and Cd doped InP were about equal, but the introduction rate of the defect H5 varied strongly among the three types of material. The introduction rate of H5 was highest in the heavily Zn doped InP but the lowest in the heavily Cd doped InP, even though they were doped comparably. As a result, the total defect introduction rate was lowest in the highly Cd doped InP.The results can be interpreted in terms of the models for the formation and annealing of defects, and by the different diffusion rates of Zn and Cd in InP.


2007 ◽  
Vol 131-133 ◽  
pp. 363-368 ◽  
Author(s):  
Vladimir P. Markevich ◽  
Anthony R. Peaker ◽  
I.F. Medvedeva ◽  
Vasilii E. Gusakov ◽  
L.I. Murin ◽  
...  

The influence of Cu contamination on radiation-induced defect reactions in n-type Czochralski-grown silicon (Cz-Si) crystals has been studied by means of the Hall effect technique, deep level transient spectroscopy (DLTS) and high-resolution Laplace DLTS with supporting theoretical modeling of defects. It is found that the contamination of Cz-Si samples with Cu does not influence significantly the energy spectrum and introduction rates of the principal electrically active defects induced by electron irradiation. The vacancy-oxygen (VO) centre, divacancy (V2) and a complex consisting of a silicon self-interstitial with the oxygen dimer (IO2) are found to be the dominant radiation-induced defects in Cu-contaminated samples as well as in uncontaminated ones. An isochronal annealing study has shown that the presence of Cu affects the annealing behaviour of the vacancy-related defects. In Cu-doped samples the VO centre disappears upon annealing at significantly lower temperatures (175-250°C) compared to those of the VO disappearance in the uncontaminated samples (300-375°C). The disappearance of the VO centres in the Cu-doped samples occurs simultaneously with an anti-correlated introduction of a defect with an energy level at about Ec- 0.60 eV. It is suggested that this defect is formed by the interaction of a mobile Cu atom with the VO complex. According to results of quantum-chemical modelling, in the most stable configuration of the Cu-VO defect a Cu atom occupies a tetrahedral interstitial position nearest to the elongated Si-Si bond of the VO centre. The presence of the Cu atom is found to result in the further elongation of the Si-Si bond and a shift of the VO acceptor level to the middle of the gap. The annealing behaviour of V2 has also been found to be different in the irradiated Cu-doped samples compared to that in the uncontaminated ones. The most probable reason for this difference is an interaction of mobile Cu atoms with di-vacancies. An energy level at about Ec-0.17 eV has been tentatively assigned to a complex consisting of a Cu atom and a di-vacancy.


2005 ◽  
Vol 483-485 ◽  
pp. 365-368 ◽  
Author(s):  
Giovanni Alfieri ◽  
Edouard V. Monakhov ◽  
Margareta K. Linnarsson ◽  
Bengt Gunnar Svensson

Deep level transient spectroscopy (DLTS) was employed to investigate the annealing behaviour and thermal stability of radiation induced defects in nitrogen doped 4H-SiC epitaxial layers, grown by chemical vapor deposition (CVD). The epilayers have been irradiated with 15 MeV electrons and an isochronal annealing series has been carried out. The measurements have been performed after each annealing step and six electron traps located in the energy band gap range of 0.42-1.6 eV below the conduction band edge (Ec) have been detected.


2002 ◽  
Vol 389-393 ◽  
pp. 489-492 ◽  
Author(s):  
Atsuo Kawasuso ◽  
Michael Weidner ◽  
F. Redmann ◽  
Thomas Frank ◽  
Reinhard Krause-Rehberg ◽  
...  

2017 ◽  
Vol 373 ◽  
pp. 209-212 ◽  
Author(s):  
Yurii V. Funtikov ◽  
Leonid Yu. Dubov ◽  
Yurii V. Shtotsky ◽  
Sergey V. Stepanov

Experiments on investigation of the radiation defects produced as a result of high energy proton irradiation of single crystal Si wafers are carried out. Parameters of the proton irradiation facility are presented. It is shown that the most efficient radiation defect formation correlates with the position of the Bragg peak of ionization losses. LT spectra were measured just after irradiation and then after keeping Si samples during 3 months of at room T. We did not observe any variation of the number density of the defects, except for the 7th wafer, where most part of protons was stopped. An efficient annealing of the vacancy-type defects starts at temperatures slightly lower than 100 °C (during 10 min). Annealing at about 700 °C leads to recovering of the monoexponrntial shape of the LT spectra.


1994 ◽  
Vol 373 ◽  
Author(s):  
Masafumi Yamaguchi ◽  
Koshi Ando ◽  
Hidehiko Kamada

AbstractIrradiation effects of high-energy electrons and protons, and 60Co gamma-rays on InP-related materials have been examined in comparison with those of GaAs and Si. Superior radiation-resistance of InP-related materials and their devices compared to GaAs and Si has been found by using deep-level transient spectroscopy (DLTS), photoluminescence (PL) and properties of devices such as solar cells and lightemitting devices. Moreover, minority-carrier injection enhanced annealing phenomena of radiation-induced defects in InP-related materials have also been observed even at low temperature of around 150K.


2015 ◽  
Vol 66 (6) ◽  
pp. 323-328 ◽  
Author(s):  
Ladislav Harmatha ◽  
Miroslav Mikolášek ◽  
L’ubica Stuchlíková ◽  
Arpád Kósa ◽  
Milan Žiška ◽  
...  

Abstract The contribution is focused on the diagnostics of structures with a heterojunction between amorphous and crystalline silicon prepared by HIT (Heterojunction with an Intrinsic Thin layer) technology. The samples were irradiated by Xe ions with energy 167 MeV and doses from 5 × 108 cm−2 to 5 × 1010 cm−2. Radiation defects induced in the bulk of Si and at the hydrogenated amorphous silicon and crystalline silicon (a-Si:H/c-Si) interface were identified by Deep Level Transient Spectroscopy (DLTS). Radiation induced A-centre traps, boron vacancy traps and different types of divacancies with a high value of activation energy were observed. With an increased fluence of heavy ions the nature and density of the radiation induced defects was changed.


Author(s):  
Ivana Capan ◽  
Tomislav Brodar ◽  
Takahiro Makino ◽  
Vladimir Radulovic ◽  
Luka Snoj

We report on metastable defects introduced in n-type 4H-SiC material by epithermal and fast neutron irradiation. The epithermal and fast neutron irradiation defects in 4H-SiC are much less explored compared to electron or proton irradiation induced defects. In addition to silicon vacancy (Vsi) and carbon antisite-carbon vacancy (CAV) complex, the neutron irradiation has introduced four deep level defects, all arising from the metastable defect, the M-center. The metastable deep level defects were investigated by deep level transient spectroscopy (DLTS), high-resolution Laplace DLTS (L-DLTS) and isothermal DLTS. The existence of the fourth deep level M4, recently observed in ion implanted 4H-SiC, has been additionally confirmed in neutron irradiated samples. The isothermal DLTS technique has been proven as a useful tool for studying the metastable defects.


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