Interstitial Carbon in p-Type Copper-Doped Silicon

2015 ◽  
Vol 242 ◽  
pp. 302-307
Author(s):  
Nikolai Yarykin ◽  
Jörg Weber

The spectrum of defects produced by 5 MeV electron irradiation at room temperature in the oxygen-lean p-type silicon strongly contaminated with interstitial copper (Cui) is studied using the deep-level transient spectroscopy. It is observed that the interstitial carbon defects (Ci), which are abundant in irradiated copper-free samples, are not detected directly after irradiation. The phenomenon is attributed to the formation of a {Cui, Ci} complexes which exhibit no deep levels in the lower half of the band gap. The complexes are shown to dissociate under anneals at 300-340 K resulting in the appearance of the Ci species.

2015 ◽  
Vol 242 ◽  
pp. 308-311 ◽  
Author(s):  
Nikolai Yarykin ◽  
Jörg Weber

The spectrum of defects produced by 5 MeV electron irradiation in oxygen-lean p-type silicon strongly contaminated with interstitial copper (Cui) is studied using the deep-level transient spectroscopy. It is observed that the room-temperature irradiation creates a large amount of CuPL centers (complexes including one substitutional and three interstitial Cu atoms). The analysis shows that this process is govern by formation of the substitutional copper atoms due to the direct reaction between irradiation-induced vacancies and mobile Cui species. This reaction consumes nearly all irradiation-induced vacancies and affects strongly the standard spectrum of radiation defects.


2013 ◽  
Vol 740-742 ◽  
pp. 373-376 ◽  
Author(s):  
Kazuki Yoshihara ◽  
Masashi Kato ◽  
Masaya Ichimura ◽  
Tomoaki Hatayama ◽  
Takeshi Ohshima

We have characterized deep levels in as-grown and electron irradiated p-type 4H-SiC epitaxial layers by the current deep-level transient spectroscopy (I-DLTS) method. A part of the samples were irradiated with electrons in order to introduce defects. As a result, we found that electron irradiation to p-type 4H-SiC created complex defects including carbon vacancy or interstitial. Moreover, we found that observed deep levels are different between before and after annealing, and thus annealing may change structures of defects.


2011 ◽  
Vol 679-680 ◽  
pp. 253-256 ◽  
Author(s):  
Giovanni Alfieri ◽  
Tsunenobu Kimoto

An isochronal annealing in the 100-1200 oC temperature range was carried out on 116 and 400 keV electron irradiated Al-doped 6H-SiC epitaxial layers. Electrical characterization of the epilayers, performed by Fourier-Transform Deep Level Transient Spectroscopy, revealed the presence of six levels in the band gap, in the 0.1-1.6 eV energy range. Their nature is discussed in the light of previous experimental and theoretical works found in the literature.


2004 ◽  
Vol 815 ◽  
Author(s):  
A. O. Evwaraye ◽  
S. R. Smith ◽  
W. C. Mitchel ◽  
G. C. Farlow ◽  
M. A. Capano

AbstractArgon ions (Ar+) were implanted into n-type 4H-SiC epitaxial layers at 600 °C. The energy of the ions was 160 keV and at a dose of 2 × 1016 cm−2. After post-implantation annealing at 1600 °C, Schottky diodes were fabricated on the ion implanted samples. Bulk n-type 4H-SiC samples were irradiated at room temperature with 1 MeV electrons at doses of 1 × 1016 to 5.1 × 1017 el/cm2. The current density of the beam was 0.91 μA/cm2. Deep Level Transient Spectroscopy (DLTS) was used to characterize the induced defects. DLTS studies of Ar+ implanted samples showed six defect levels at EC – 0.18 eV, EC – 0.23eV, EC – 0.31eV, EC – 0.38 eV, EC – 0.72 eV, and EC – 0.81 eV. Z1/Z2 defect is the dominant defect in the electron irradiated sample and anneals out completely after 10 minutes at 1000 °C. However, Z1/Z2 defect in Ar+ implanted samples was stable up to 1600 °C. It is suggested that the annealing behavior of Z1/Z2 depends on the source of its formation.


2007 ◽  
Vol 556-557 ◽  
pp. 331-334 ◽  
Author(s):  
Katsunori Danno ◽  
Tsunenobu Kimoto

The authors have investigated deep levels in electron-irradiated n- and p-type 4H-SiC epilayers by deep level transient spectroscopy (DLTS). By low-energy electron irradiation at 116 keV, the Z1/2 and EH6/7 concentrations are increased in n-type samples, and the concentrations are almost unchanged after annealing at 950°C for 30 min. In p-type samples, the unknown centers, namely EP1 and EP2, are introduced by irradiation. By annealing at 950°C, the unknown centers are annealed out. The HK4 center (EV + 1.44 eV) is increased by the electron irradiation and subsequent annealing at 950°C. The dependence of increase in the trap concentrations by irradiation (NT) on the electron fluence reveals that NT for the Z1/2 and EH6/7 centers is in proportional to the 0.7 power of electron fluence, while the slope of the plot is 0.5 for the HK4 center. The Z1/2 and EH6/7 centers show similar annealing stage and are thermally stable up to 1500-1600°C, while the HK4 center is annealed out at about 1350°C. The Z1/2 and EH6/7 centers may be derived from a same origin (single carbon vacancy: VC) but different charge state. The HK4 center may be a complex including VC.


1998 ◽  
Vol 510 ◽  
Author(s):  
Min Gong ◽  
C. D. Beling ◽  
S. Fung ◽  
G. Brauer ◽  
H. Wirth ◽  
...  

AbstractTwo deep levels, located at Ev+0.26eV and Ec-0.44eV, in Al-implanted n-type samples and one at Ev+0.48eV in p-type samples have been observed by the deep level transient spectroscopy. The level of is identified as the shallower aluminum-acceptor. The 1.7 MeV electron-irradiation, used as a probe to distinguish the implantation induced deep-levels, induces at least six electron traps in the n-SiC and one hole-trap in the p-type material. The peak positions of these deep-levels in DLTS spectra are quite different from those induced by Al-implantation. This result suggests that various damages are formed after heavy ion (Al) and light particle (e) irradiation.


1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  

AbstractA 1-MeV-electron-irradiation (EI) induced trap at Ec-0.18 eV is found in n-type GaN by deep level transient spectroscopy (DLTS) measurements on Schottky barrier diodes, fabricated on both metal-organic-chemical-vapor-deposition and hydride-vapor-phase-epitaxy material grown on sapphire. The 300-K carrier concentrations of the two materials are 2.3 × 1016 cm−3 and 1.3 × 1017 cm−3, respectively. Up to an irradiation dose of 1 × 1015 cm−2, the electron concentrations and pre-existing traps in the GaN layers are not significantly affected, while the EI-induced trap is produced at a rate of at least 0.2 cm−1. The DLTS peaks in the two materials are shifted slightly, possibly due to electric-field effects. Comparison with theory suggests that the defect is most likely associated with the N vacancy or Ga interstitial.


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