The Effect of Impurity Content and Ion Mass on the Depth Profiles of Vacancy-Type Defects in MeV Implanted Si

1996 ◽  
Vol 438 ◽  
Author(s):  
S. Libertino ◽  
S. Coffa ◽  
V. Privitera ◽  
F. Priolo

AbstractWe used deep level transient spectroscopy to determine the concentration and depth profile of the defects introduced by MeV He and Si implants in n-type crystalline Si. We have found that only ∼ 16% of the Frenkel pairs generated by the ion escapes recombination and is stored into room temperature stable defects such as divacancies and oxygen vacancy complexes. For a light ion (He), the depth distribution of these defect complexes is strongly dependent on the O content of the substrate: it mirrors the initial distribution of I-V pairs, as calculated by TRIM (a Monte Carlo Code) when the O content is high (∼ 1018/cm3) while it can be much wider (up to 2 μm) in a highly pure (low O content) epitaxial substrate. This effect is due to a long range migration of vacancies before clustering or trapping at impurities. This migration is strongly inhibited for an ion of higher mass (such as Si) since in a denser collision cascade direct clustering is strongly favoured with respect to agglomeration of migrating defects.

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Libertino ◽  
S. Coffa ◽  
V. Privitera ◽  
F. Priolo

AbstractWe used deep level transient spectroscopy to determine the concentration and depth profile of the defects introduced by MeV He and Si implants in n-type crystalline Si. We have found that only ˜ 16% of the Frenkel pairs generated by the ion escapes recombination and is stored into room temperature stable defects such as divacancies and oxygen vacancy complexes. For a light ion (He), the depth distribution of these defect complexes is strongly dependent on the O content of the substrate: it mirrors the initial distribution of I–V pairs, as calculated by TRIM (a Monte Carlo Code) when the O content is high (˜1018/cm3) while it can be much wider (up to 2 μm) in a highly pure (low O content) epitaxial substrate. This effect is due to a long range migration of vacancies before clustering or trapping at impurities. This migration is strongly inhibited for an ion of higher mass (such as Si) since in a denser collision cascade direct clustering is strongly favoured with respect to agglomeration of migrating defects.


1997 ◽  
Vol 469 ◽  
Author(s):  
V. Privitera ◽  
S. Coffa ◽  
K. Kyllesbech Larsen ◽  
S. Libertino ◽  
G. Mannino ◽  
...  

ABSTRACTOur recent work on the room temperature migration and trapping phenomena of self-interstitials and vacancies in crystalline Si is reviewed. Spreading resistance profiling and deep level transient spectroscopy measurements were used to monitor the interaction of ion beam generated defects with dopant atoms, intrinsic impurities (i.e. O and C), pre-existing defect marker layers and sample surface. We have found that both interstitials and vacancies undergo fast long range migration which is interrupted by trapping at impurities and by recombination at defects or at the surface. Effective defect migration lengths as large as 5 μm at room temperature have been observed in highly pure, defect free epitaxial Si samples. A lower limit of 1×10−10 cm2/sec for the room temperature diffusivity of self-interstitials has been determined. Furthermore, by monitoring the migration and interaction processes of point defects injected through a mask, we have established that surface acts as an effective sink for the migrating Si self interstitials.


2009 ◽  
Vol 615-617 ◽  
pp. 469-472
Author(s):  
Filippo Fabbri ◽  
Francesco Moscatelli ◽  
Antonella Poggi ◽  
Roberta Nipoti ◽  
Anna Cavallini

Capacitance versus Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) measurements of Al+ implanted p+n diodes with Al+ implanted Junction Termination Extension are here studied. These diodes present C-V characteristics like graded junction for low forward bias values, i.e. > 0.4 V , or like abrupt junctions for large reverse bias, i.e. between 0.4V and -10V. The depth range of the graded junction, computed by the capacitance values, is much larger than the simulated tail of the ion implanted Al+ profile. DLTS spectra have been measured both in injection and standard configuration and always show minority carrier traps in the temperature range 0-300K. Three are the minority carrier related peaks, one attributed to the Al acceptor and the others to the D and D1 defects. The depth distribution of these hole traps will be discussed with respect to the apparent carrier concentration, obtained by C-V analysis.


2001 ◽  
Vol 692 ◽  
Author(s):  
S. Pizzini ◽  
S. Binetti ◽  
E. Leoni ◽  
A. Le Donne ◽  
M. Acciarri ◽  
...  

AbstractThere is a recent, renewed attention on the possible development of optical emitters compatible with silicon microelectronic technology and it has been recently shown that light emitting diodes could be manufactured on dislocated silicon, where dislocations were generated by plastic deformation or ion implantation. Among other potential sources of room temperature light emission, compatible with standard silicon-based ULSI technology, we have studied old thermal donors (OTD), as the origin of their luminescence is still matter of controversy and demands further investigation.In this work we discuss the results of a spectroscopical study of OTD using photoluminescence (PL) and Deep Level Transient Spectroscopy (DLTS) on standard Czochralsky (Cz) silicon samples and on carbon-doped samples.We were able to show that their main optical activity, which consists of a narrow band at 0.767 eV ( P line), is correlated to a transition from a shallow donor level of OTD to a deep level at EV+0.37 eV which is tentatively associated to C-O complexes. As we have shown that the P line emission persists at room temperature, we discuss about its potentialities to silicon in optoelectronic applications.


1998 ◽  
Vol 532 ◽  
Author(s):  
C. R. Cho ◽  
R. A. Brown ◽  
O. Kononchuk ◽  
N. Yarykin ◽  
G. Rozgonyi ◽  
...  

ABSTRACTThe evolution of defects in Czochralski and epitaxial p- and n-type silicon wafers following irradiation with He. Si or Ge ions at 80 K has been investigated by in situ deep level transient spectroscopy (DLTS). Defect annealing and formation reactions have been observed over the temperature range 80–350 K. In p-type silicon, new species-dependent levels are observed immediately after implantation, but these levels anneal out at or below room temperature. The wellknown divacancy and interstitial defects, usually reported after room temperature implantation, are revealed in the DLTS spectra only upon annealing at 160–200 K. In n-type silicon, vacancy-oxygen pairs are observed immediately after implantation. However, vacancy-related defects continue to form over a broad temperature range in samples implanted with Si or Ge. These observations are consistent with a model whereby vacancies and interstitials are released from defect clusters at temperatures >200 K to form divacancies and other defect pairs which are stable at room temperature.


1998 ◽  
Vol 513 ◽  
Author(s):  
M. Janson ◽  
M. K. Linnarsson ◽  
A. Hallén ◽  
B. G. Svensson

ABSTRACTEpitaxial layers of low doped 4H-SiC are implanted with 20 keV 2H+ ions to a dose of 1×1015 cm−2. The samples are subsequently annealed at temperatures ranging from 1040 to 1135 °C. Secondary ion mass spectrometry is used to obtain the concentration versus depth profiles of the atomic deuterium in the samples. It is found that the concentration of implanted deuterium decreases rapidly in the samples as a function of anneal time.The experimental data are explained by a model where the deuterium migrates rapidly and becomes trapped and de-trapped at implantation-induced defects which exhibit a slightly shallower depth distribution than the implanted deuterium ions. Computer simulations using this model, in which the damage profile is taken from Monte Carlo simulations and the surface is treated as a perfect sink for the diffusing deuterium atoms, are performed with good results compared to the experimental data. The complexes are tentatively identified as carbon-deuterium at a Si-vacancy and a dissociation energy (ED) of approximately 4.9 eV is extracted for the deuterium-vacancy complexes.


2009 ◽  
Vol 615-617 ◽  
pp. 381-384 ◽  
Author(s):  
Masashi Kato ◽  
Kosuke Kito ◽  
Masaya Ichimura

We measured the temperature dependence of the electrical resistivity for two high-purity undoped 6H-SiC bulk wafers with resistivities of 1.5103 cm and 8.3108 cm at room temperature. We also characterized the deep levels affecting the semi-insulating property by current deep level transient spectroscopy (I-DLTS) and photo induced current level transient spectroscopy (PICTS) measurements. The activation energies of the resistivity were 0.11 eV and 0.59 eV for the samples with lower and higher resistivities, respectively. In I-DLTS and PICTS spectra, the sample with lower resistivity shows a donor level at Ec0.17 eV and two acceptor levels around Ec0.40 eV, while the sample with higher resistivity shows acceptor levels at Ec0.77 eV and Ev+0.46 eV. We calculated the temperature dependence of the resistivity with a model considering one donor level and one acceptor level based on parameters from I-DLTS peaks. We reproduced the experimental results only for the sample with lower resistivity. The acceptor level near the valence band needs to be considered to explain the resistivity for the sample with higher resistivity.


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