Evolution Of Defects Induced By High Energy He Implantation In Gold-Diffused Silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
R. El Bouayadi ◽  
G. Regula ◽  
B. Pichaud ◽  
M. Lancin ◽  
J. J. Simon ◽  
...  

ABSTRACTSilicon samples were gold-diffused at different temperatures, implanted with He ions at 1.6 MeVand then annealed at 1050°C for 2 hours. The implantation induced-defect structure and their distributionin the depth of the sample, studied by conventional and high resolution cross section electron microscopy (HRXTEM) depend on the gold level introduced in the wafer prior to the gettering process. A high concentration of gold in silicon seems to influence the defect configuration in the cavity zone. Indeed, gold chemisorbed atcavities can homogenize the surface energy of their planes in different orientations, and can increase the cavity critical diameter beyond they become facetted. Secondary ion mass spectroscopy (SIMS) profiles exhibit ashouldered shape and a width closely related to the presence of the defects (observed by XTEM) which are veryefficient sinks both for gold and copper atoms. Unfortunately, the electrical improvement of the material (checked by minority carriers diffusion length measurements MCDL) is not achieved by this gettering process, probably due to the high metal impurity concentrations remaining out of the gettering zone, to the presence of AuCu complexes and η-Cu3Si precipitates identified by deep level transient spectroscopy (DLTS)measurements and HRXTEM observations respectively.

2009 ◽  
Vol 156-158 ◽  
pp. 167-172
Author(s):  
Pavel Hazdra ◽  
Volodymyr V. Komarnitskyy

The influence of platinum contamination on the stability of radiation defects produced by high-energy proton irradiation was investigated in the low-doped n-type float-zone oxygen rich silicon forming the base of power p+nn+ diodes. Platinum was first implanted and then in-diffused at different temperatures to obtain different levels of contamination. Diodes were then implanted with 1.8 MeV protons to a fluence of 2x1010 cm-2 and radiation defect reaction during isochronal annealing were investigated by deep-level transient spectroscopy. Results show that contamination of silicon by platinum atoms influences significantly both the introduction rates and the temperature stability of dominant radiation defects (vacancy-oxygen pairs, divacancies and VOH complexes).


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1966
Author(s):  
Domenico Pellegrino ◽  
Lucia Calcagno ◽  
Massimo Zimbone ◽  
Salvatore Di Franco ◽  
Antonella Sciuto

In this study, 4H-SiC p–n junctions were irradiated with 700 keV He+ ions in the fluence range 1.0 × 1012 to 1.0 × 1015 ions/cm2. The effects of irradiation were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements, while deep-level transient spectroscopy (DLTS) was used to study the traps introduced by irradiation defects. Modifications of the device’s electrical performances were observed after irradiation, and two fluence regimes were identified. In the low fluence range (≤1013 ions/cm2), I–V characteristics evidenced an increase in series resistance, which can be associated with the decrease in the dopant concentration, as also denoted by C–V measurements. In addition, the pre-exponential parameter of junction generation current increased with fluence due to the increase in point defect concentration. The main produced defect states were the Z1/2, RD1/2, and EH6/7 centers, whose concentrations increased with fluence. At high fluence (>1013 ions/cm2), I–V curves showed a strong decrease in the generation current, while DLTS evidenced a rearrangement of defects. The detailed electrical characterization of the p–n junction performed at different temperatures highlights the existence of conduction paths with peculiar electrical properties introduced by high fluence irradiation. The results suggest the formation of localized highly resistive regions (realized by agglomeration of point defects) in parallel with the main junction.


2008 ◽  
Vol 607 ◽  
pp. 134-136
Author(s):  
Y.J. Zhang ◽  
Ai Hong Deng ◽  
You Wen Zhao ◽  
J. Yu ◽  
X.X. Yu ◽  
...  

Positron annihilation lifetime (PAL) spectroscopy,photo-induced current transient spectroscopy (PICTS) and thermally stimulated current (TSC) have been employed to study the formation of compensation defects and their evolvement under iron phosphide (IP) ambience or pure phosphide (PP) ambience. In the formation of IP SI-InP, the diffusion of Fe atoms suppresses the formation of some open-volume defects. As to PP SI-InP, VInH4 complexes dissociate into acceptor vacancies VInHn(n-3)(n=0,1,2,3), which compensate residual donor type defects and make the sample semi-insulating. Electron irradiation-induced deep level defects have been studied by TSC in PP and IP SI-InP, respectively. In contrast to a high concentration of irradiation-induced defects in as-grown and PP annealed InP, IP SI-InP has a very low concentration of defects.


1999 ◽  
Vol 572 ◽  
Author(s):  
T. Henkel ◽  
Y. Tanaka ◽  
N. Kobayashi ◽  
H. Tanoue ◽  
M. Gong ◽  
...  

ABSTRACTStructural and electrical properties of beryllium implanted silicon carbide have been investigated by secondary ion mass spectrometry, Rutherford backscattering as well as deep level transient spectroscopy, resistivity and Hall measurements. Strong redistributions of the beryllium profiles have been found after a short post-implantation anneal cycle at temperatures between 1500 °C and 1700 °C. In particular, diffusion towards the surface has been observed which caused severe depletion of beryllium in the surface region. The crystalline state of the implanted material is well recovered already after annealing at 1450 °C. However, four deep levels induced by the implantation process have been detected by deep level transient spectroscopy.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
T. Nowozin ◽  
A. Wiengarten ◽  
L. Bonato ◽  
D. Bimberg ◽  
Wei-Hsun Lin ◽  
...  

The electronic properties of a self-assembled GaSb/GaAs QD ensemble are determined by capacitance-voltage (C-V) and deep-level transient spectroscopy (DLTS). The charging and discharging bias regions of the QDs are determined for different temperatures. With a value of 335 (±15) meV the localization energy is rather small compared to values previously determined for the same material system. Similarly, a very small apparent capture cross section is measured (1·10−16 cm2). DLTS signal analysis yields an equivalent to the ensemble density of states for the individual energies as well as the density function of the confinement energies of the QDs in the ensemble.


2001 ◽  
Vol 692 ◽  
Author(s):  
Daniel K. Johnstonea ◽  
Mohamed Ahoujjab ◽  
Yung Kee Yeoc ◽  
Robert L. Hengeholdc ◽  
Louis Guidod

AbstractGaN and its related alloys are being widely developed for blue-ultraviolet emitting and detection devices as well as high temperature, high power, and high frequency electronics. Despite the fast improvement in the growth of good quality GaN, a high concentration of deep level defects of yet unconfirmed origins are still found in GaN. For both optical and electronic devices, these deep carrier traps and/or recombination centers are very important and must therefore be understood. In the present work, deep level defects in GaN grown on sapphire substrates by metal organic chemical vapor deposition (MOCVD) have been investigated using Isothermal Capacitance Transient Spectroscopy (ICTS) and Current Voltage Temperature (IVT) measurements. Several deep level electron traps were characterized, obtaining the emission energy, concentration, and capture cross section from a fit of exponentials to the capacitance transients. ICTS was also used to reveal information about the capture kinetics involved in the traps found in GaN by measuring the amplitude of the capacitance transient at each temperature. At a reduced filling pulse where the traps were not saturated, several of them showed marked reduction in capacitance transient amplitude when compared to the transient amplitude measured under conditions where the filling pulse saturates the traps. This reduction in transient amplitude indicates that there is a barrier to carrier capture, in addition to the emission barrier. It has been found that several traps had capture barriers that were significant fractions of the emission energies up to 0.32 eV. These capture barriers may lead to persistent photoconductivity and reduced trapping. In this paper, deep level emission energies as well as capture barrier energies found in MOCVD-grown GAN will be discussed.


1996 ◽  
Vol 442 ◽  
Author(s):  
P. N. K. Deenapanray ◽  
F. D. Auret ◽  
C. Schutte ◽  
G. Myburg ◽  
W. E. Meyer ◽  
...  

AbstractWe have employed current-voltage (IV), capacitance-voltage (CV) and deep level transient spectroscopy (DLTS) techniques to characterise the defects induced in n-Si during RF sputter-etching in an Ar plasma. The reverse leakage current, at a bias of 1 V, of the Schottky barrier diodes fabricated on the etched samples was found to decrease with etch time reaching a minimum at 6 minutes and thereafter increased. The barrier heights followed the opposite trend. The plasma processing introduced six prominent deep levels below the conduction band of the substrate. A comparison with the defects induced during high energy (MeV) alpha-particle, proton and electron irradiation of the same material revealed that plasma-etching created the VO- and VP-centres, and V2-10. Some of the remaining sputter-etching-induced (SEI) defects have tentatively been related to those formed during either 1 keV He- or Ar-ion bombardment.


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 719 ◽  
Author(s):  
Gabrielle Regula ◽  
Rachid El Bouayadi ◽  
Bernard Pichaud ◽  
Sylvie Godey ◽  
Romain Delamare ◽  
...  

AbstractSilicon samples were implanted with He ions at 1.6 MeV using doses ranging from 1×1016 cm-2 to 1×1017cm-2 with different fluxes (0.4νA/cm2 - 2.0νA/cm2) and annealed at high (1000°C) and low temperatures (800°C). The implantation induced-defect structure and their distribution in the depth of the sample were studied by cross section electron microscopy (XTEM). An unexpected consequence of the flux on the defect population and density was found solely for 2×1016 cm-2, which is the upper threshold to get nano-bubbles at such large implantation depth. Nuclear Reaction Analysis (NRA) were performed to measure the ratio of He remaining in the bubbles as a function of time and temperature anneal. Some samples were gold or nickel diffused at temperatures ranging from 870°C to 1050°C prior to He implantation. The gettering efficiency of the implantation-induced defects was measured by secondary ion mass spectroscopy (SIMS), after a high temperature getter annealing. SIMS profiles exhibit a shape and a width closely related to the presence of the defects (observed by XTEM) which are very efficient sinks for all kinds of metal impurities. The bubbles were found to be more efficient traps than the dislocation loops.


1998 ◽  
Vol 532 ◽  
Author(s):  
F. Boussaid ◽  
F. Olivie ◽  
M. Benzohra ◽  
D. Alquier ◽  
A. Claverie ◽  
...  

ABSTRACTUltra-shallow p+ -n junctions have been obtained from Ge+ -preamorphized and crystalline <100> silicon substrates. B+ and BF2+ dopants have been used. Boron was implanted at low energy 3 keV / 1015 cm−2 while an equivalent energy of 15 keV / 1015 cm−2 was chosen for BF2+. Rapid Thermal Annealing (RTA) for 15 s at 950 °C was then used for dopant electrical activation and implantation damage removal. Electrically active defects in these samples were characterized using Deep Level Transient Spectroscopy (DLTS) and isothermal transient capacitance (ΔC(t, T)). Two electron traps were detected in the upper half of the band gap at Ec – 0.20 eV and Ec – 0.45 eV, respectively. These traps are shown to be induced by the Ge+ preamorphization stage. Dopant implantation along with RTA result in the formation of a depth distributed energy continuum for B+ and BF2+ implants. Each continuum has been ascribed to annealing residual defects. Low energy B+ implantation is seen to induce twice as many defects as BF2+, implantation. From isothermal transient capacitance (ΔC(t, T)), reliable damage concentration profiles have been obtained, revealing that preamorphization induces not only defects in the regrown silicon layer but also a relatively high concentration of electrically active defects up to 3.5 μm into the bulk.


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