Point Defects Migration and Agglomeration in Si at Room Temperature: The Role of Surface and Impurity Content

1997 ◽  
Vol 469 ◽  
Author(s):  
V. Privitera ◽  
S. Coffa ◽  
K. Kyllesbech Larsen ◽  
S. Libertino ◽  
G. Mannino ◽  
...  
Keyword(s):  
Point Defects ◽  
Room Temperature ◽  
Deep Level ◽  
Ion Beam ◽  
Impurity Content ◽  
Sample Surface ◽  
Defect Migration ◽  
Transient Spectroscopy ◽  
Dopant Atoms

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.

Point-Defect Migration in Crystalline Si: Impurity Content, Surface and Stress Effects

1998 ◽  
Vol 532 ◽  
Author(s):  
S. Coffa ◽  
S. Libertino ◽  
A. La Magna ◽  
V. Privitera ◽  
G. Mannino ◽  
...  
Keyword(s):  
Point Defect ◽  
Leakage Current ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Deep Level ◽  
Ion Beam ◽  
Impurity Content ◽  
Ex Situ ◽  
Defect Migration

ABSTRACTThe results of several recent experiments aimed at assessing the room temperature migration properties of interstitials (D) and vacancies (V) in ion implanted crystalline Si are reviewed. We show that combining the results of ex-situ techniques (deep level transient spectroscopy and spreading resistance profilometry) and in-situ leakage current measurements new and interesting information can be achieved. It has been found that at room temperature I and V, generated by an ion beam, undergo fast long range migration (with diffusivities higher than 10−1 cm2/sec) which is interrupted by trapping at impurities (C, O) or dopant atoms and by recombination at surface. Analysis of two-dimensional migration of point defects injected through a photolithographically defined mask shows that a strong I recombination (characterized by a coefficient of 30 μm−1) occurs at the sample surface. Moreover, we have found that the strain field induced by an oxide or a nitride mask significantly affects defect migration and produces a strong anisotropy of the defect diffusivity tensor. Finally, using in-situ leakage current measuremens, performed both during and just after ion irradiation, the time scale of point defect evolution at room temperature has been determined and defect diffusivities evaluated. The implications of these results on our current understanding of defect and diffusion phenomena in Si are discussed.

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
Keyword(s):  
Room Temperature ◽  
Depth Distribution ◽  
Deep Level ◽  
Impurity Content ◽  
Initial Distribution ◽  
Monte Carlo Code ◽  
Depth Profiles ◽  
Defect Complexes ◽  
Range Migration ◽  
Transient Spectroscopy

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.

DLTS: A Promising Technique for Understanding the Physics and Engineering of the Point Defects in Si and III-V Alloys

2007 ◽  
Vol 994 ◽  
Author(s):  
Aurangzeb Khan ◽  
Masafumi Yamaguchi
Keyword(s):  
Point Defects ◽  
Deep Level ◽  
Complete Characterization ◽  
Cell Parameters ◽  
Transient Spectroscopy ◽  
Almost All ◽  
Device Properties ◽  
Compound Materials

AbstractDeep level transient spectroscopy (DLTS) is the best technique for monitoring and characterizing deep levels introduced intentionally or occurring naturally in semiconductor materials and complete devices. DLTS has the advantage over all the techniques used to-date in that it fulfils almost all the requirements for a complete characterization of a deep centre and their correlation with the device properties. In particular the method can determine the activation energy of a deep level, its capture cross-section and concentration and can distinguish between traps and recombination centers.In this invited paper we provide an overview of the extensive R & D work that has been carrier out by the authors on the identification of the recombination and compensator centers in Si and III-V compound materials for space solar cells. In addition, we present an overview of key problems that remain in the understanding of the role of the point defects and their correlation with the solar cell parameters.

Electrical and Electrochemical Properties of a-C:N:H Films

1999 ◽  
Vol 593 ◽  
Author(s):  
Yu.V. Pleskov ◽  
M.D. Krotova ◽  
V.I. Polyakov ◽  
A.V. Khomich ◽  
A.I. Rukovishnikov ◽  
...  
Keyword(s):  
Point Defects ◽  
Electrochemical Impedance ◽  
Deep Level ◽  
Ion Beam ◽  
Plasma Source ◽  
Inductively Coupled ◽  
Active Point ◽  
Transient Spectroscopy ◽  
Quartz Substrates ◽  
Kinetics Of

ABSTRACTElectrochemical impedance in H2SO4 solutions and kinetics of redox reactions in the Fe(CN)63-/4- system were studied on amorphous nitrogenated diamond-like carbon (a-C:N:H) thin-film electrodes. Parameters of point defects (trapping centers) were also measured by the Deep Level Transient Spectroscopy techniques. The films have been fabricated on p- and i-type silicon and quartz substrates, using direct ion beam deposition from an RF inductively coupled N2+ CH4 plasma source. The increase in N2/CH4 ratio in the gas mixture lead to a decrease in the electrical resistivity and optical bandgap of the films from 3×1010to 5×106 Ω cm and from 1.3 to 0.6 eV, respectively. Simultaneously, the concentration of electrically active point defects increased significantly and the charge transfer at the a-C:N:H film/redox electrolyte interface was facilitated

Defect-Formation Dependence on Group V-Dopant Atoms in Electron-Irradiated Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
O.O. Awadelkarim ◽  
A. Henry ◽  
B. Monemar ◽  
J.L. Lindström
Keyword(s):  
Room Temperature ◽  
Defect Formation ◽  
Deep Level ◽  
Electron Trap ◽  
Defect States ◽  
Group V ◽  
Doped Silicon ◽  
Temperature Electron ◽  
Transient Spectroscopy ◽  
Dopant Atoms

AbstractThe defect states introduced in P-, As- and Sb-doped silicon upon room-temperature electron-irradiation are studied by deep-level transient spectroscopy (DLTS). Evidence is provided for the involvement of the P-atom and the vacancy in the defect complex giving rise to the prominent electron trap commonly observed at ≈ EC-0.4 eV (EC being the edge of the conduction band). This electron trap together with another at EC-0.30 eV, apparently phosphorus related, exhibit configurationally metastable behaviour. Other electron traps observed at EC-0.27 eV and Ec-0.51 eV in Sb-doped material and EC-0.34 eV in As-doped material are attributed to complexes involving Sb and As atoms, respectively.

Evidence of Defect Migration and Clustering in MeV Heavy Ion Damaged Silicon

1998 ◽  
Vol 510 ◽  
Author(s):  
Y.N. Mohapatra ◽  
P.K. Girl
Keyword(s):  
Room Temperature ◽  
Deep Level ◽  
Heavy Ion ◽  
High Dose ◽  
Defect Migration ◽  
Defect Profile ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Transient Spectroscopy ◽  
Limited Conduction

AbstractWe have studied electrically active defects created by MeV heavy ion implantation in n-silicon. The buried damaged layer, created by implanting Ar’ ions of energy 1.45 MeV and doses in the range 1013-1014 cm−2 at room temperature, is embedded within the depletion layer of a Schottky diode. The defects are characterized using capacitance-voltage (C-V), current-voltage (I-V) and deep level transient spectroscopy (DLTS). Large concentration of electrically active defects are found to occur in a region several microns beyond the ion range or the damage profile predicted by Monte Carlo simulations. The dominance of a single trap in the damaged region is established from hysteresis effect in C-V, space charge limited conduction in forward I-V characteristics and DLTS results. With annealing in the temperature range of 400-600C, the observed changes in defect charge profile indicate that the effective electrical interface moves progressively towards the surface. C-V characteristics have been simulated using model charge profiles which suggest presence of a compensated region and a sharp negatively charged defect profile at a distance much larger than that expected from ion range. Our results constitute experimental evidence of migration and clustering of interstitial related defects, even at room temperature in case of high dose irradiation.

Investigation of Damage Induced by Low Energy Focused Ion Beam Irradiation in GaAs

1993 ◽  
Vol 316 ◽  
Author(s):  
Toshihiko Kosugi ◽  
Yoshihiko Yuba ◽  
Kenji Gamo
Keyword(s):  
Focused Ion Beam ◽  
Deep Level ◽  
Ion Beam ◽  
High Energy ◽  
Low Energy ◽  
Defect Migration ◽  
Defect Centers ◽  
Energy Irradiation ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTDefects induced by Ga focused ion beam (FIB) irradiation at an energy between 0.1 and IkeV have been characterized by means of deep level transient spectroscopy (DLTS) and related capacitance measurements. Seven different kinds of defect centers were resolved and two centers at 0.33 and O.56eV below the conduction band were dominant in the 100eV Ga implanted sample at doses up to 1015/cm2. Induced defect centers were observed to distribute over the region far beyond the theoretical ion range, which resulted from defect migration during the irradiation. Low energy irradiation induced defects were readily annealed out during low temperature heat treatment in contrast to those induced by high energy irradiations.

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

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Libertino ◽  
S. Coffa ◽  
V. Privitera ◽  
F. Priolo
Keyword(s):  
Room Temperature ◽  
Depth Distribution ◽  
Deep Level ◽  
Impurity Content ◽  
Initial Distribution ◽  
Monte Carlo Code ◽  
Depth Profiles ◽  
Defect Complexes ◽  
Range Migration ◽  
Transient Spectroscopy

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.

Evaluation of On-State Resistance and Boron-Related Levels in n-Type 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 425-428 ◽  
Author(s):  
R.R Ciechonski ◽  
Samuele Porro ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova
Keyword(s):  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Depth Profiling ◽  
Thermionic Emission ◽  
Barrier Heights ◽  
Transient Spectroscopy ◽  
State Resistance ◽  
Thick Layers

Specific on-resistance Ron estimated from current density-voltage characteristics of Schottky diodes on thick layers exhibits variations from tens of mW.cm2 to tens of W.cm2 for different doping levels. In order to understand the occurrence of high on-state resistance, Schottky barrier heights were first estimated for both forward and reverse bias with the application of thermionic emission theory and were in agreement with a literature reported values. Decrease in mobility with the temperature was observed and its dependencies of T–1.3 and T–2.0 for moderately doped and low doped samples respectively were estimated. From deep level measurements by Minority Carrier Transient Spectroscopy, an influence of shallow boron related levels and D-center on dependence of on-state resistance was observed, being more pronounced in low doped samples. Similar tendency was observed in depth profiling of Ron. This suggests a major role of boron in a compensation mechanism thus resulting in high Ron.

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