Degradation and Recovery of Boron Doped Strained Silicon Germanium Layers After 1-MeV Electron Irradiation

1992 ◽  
Vol 281 ◽  
Author(s):  
H. Ohyama ◽  
J. Vanhellemont ◽  
M.-A. Trauwaert ◽  
J. Poortmans ◽  
M. Caymax ◽  
...  

ABSTRACT1007×100 μm2 n+− Si/p-Si1−x Gex diodes fabricated on conventional p-type Si substrates are irradiated at room temperature with 1-MeV electrons with fluences from 1.0×1014 to 1.0×1015 e/cm2 in a high voltage transmission electron microscope. The boron concentration and germanium fraction of the Si1−x Gex epitaxial layer used for the diodes in this study are 5×1017 cm−3 and x = 0.12, respectively. The degradation of diodes is investigated by means of current/voltage and capacitance/voltage measurements. The characteristics of the electrically active defects induced in the Si1−x Gex epitaxial layer by irradiation are also examined by using deep level transient spectroscopy and capacitance/temperature measurements. The degradation of the diode performance and the presence of deep levels are investigated as a function of electron fluence. In order to examine the recovery process, an isochronal thermal anneal is performed in the temperature range between 100 and 400°C.

1998 ◽  
Vol 510 ◽  
Author(s):  
D.Z. Chi ◽  
S. Ashok ◽  
D. Theodore

AbstractThermal evolution of ion implantation-induced defects and the influence of concurrent titanium silicidation in pre-amorphized p-type Si (implanted with 25 KeV, 1016 cm2Si+) under rapid thermal processing (RTP) have been investigated. Presence of implantation-induced electrically active defects has been confirmed by current-voltage (IV) and deep level transient spectroscopy (DLTS) measurements. DLTS characterization results show that the evolution of electrically active defects in the Si implanted samples under RTP depend critically on the RTP temperature: Hole traps HI (0.33 eV) and H4 (0.47 eV) appear after the highest temperature (950 °C) anneal, while a single trap H3 (0.26 eV) shows up at lower anneal temperatures (≤ 900 °C). The thermal signature of H4 defect is very similar to that of the iron interstitial while those of HI and H3 levels appear to originate from some interstitial-related defects, possibly complexes. A most interesting finding is that the above interstitial related defects can be eliminated completely with Ti silicidation, apparently a result of vacancy injection. However the silicidation process itself introduces a new H2 (0.30 eV) level, albeit at much lower concentration. This same H2 level is also seen in unimplanted samples under RTP. The paper will present details of defect evolution under various conditions of RTP for samples with and without the self-implantation and silicidation.


1995 ◽  
Vol 378 ◽  
Author(s):  
Aditya Agarwal ◽  
S. Koveshnikov ◽  
K. Christensen ◽  
G. A. Rozgonyi

AbstractThe electrical properties of residual MeV ion implantation damage in Si after annealing from 600 to 1100°C for 1 hour have been investigated using Deep Level Transient Spectroscopy, Capaciatance-Voltage, and Current-Voltage measurements. These data have been correlated with structural defects imaged by Transmission Electron Microscopy. It is shown that at least 4 deep levels are associated with the buried layer of extended defects after annealing at 800, 900, 1000 and 1100°C. Additionally, for the wafer annealed at 800°C at least 5 more deep level centers are present in the device layer above the buried defects.


1997 ◽  
Vol 469 ◽  
Author(s):  
D. Alquier ◽  
M. Benzohra ◽  
F. Boussaid ◽  
F. Olivie ◽  
A. Martinez

ABSTRACTIn this paper, we report Current-Voltage (I-V), Capacitance-Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) measurements on ultra-shallow (p+/n) junctions obtained by boron implantation into crystalline and Ge preamorphized Si-substrates. Germanium implantations were carried out at the energies of 30, 60 and 150 keV at a dose of 1015 cm−2. Boron was then implanted at an energy of 3 keV at a dose of 1015 cm−2. Dopant activation was obtained by Rapid Thermal Annealing (RTA) performed at 950°C for 15s in a nitrogen ambient. The aim of this work is to study the relation that exists between a population of End-Of-Range (EOR) defects, measured by TEM, and electrical properties of the Ge preamorphized diodes. The electrical measurements allow us to give the conduction mechanism which dominates in the diodes. Moreover, DLTS measurements showed the presence of two majority-carrier traps in direct relation with the EOR defects, measured at Ec-0,22eV and Ec-0,47eV. The presence of energy-distributed G-R centers independent upon the preamorphization stage is also discussed. Nevertheless, high quality (p+/n) junctions can be obtained by this technology with a judicious choice of Ge implantation energy.


2011 ◽  
Vol 178-179 ◽  
pp. 183-187
Author(s):  
Chi Kwong Tang ◽  
Lasse Vines ◽  
Bengt Gunnar Svensson ◽  
Eduard Monakhov

The interaction between hydrogen and the iron-boron pair (Fe-B) has been investigated in iron-contaminated boron-doped Cz-Si using capacitance-voltage measurements (CV) and deep level transient spectroscopy (DLTS). Introduction of hydrogen was performed by wet chemical etching and subsequent reverve bias annealing of Al Schottky diodes. The treatment led to the appearance of the defect level characteristic to interstitial iron (Fei) with a corresponding decrease in the concentration of the Fe-B pair. Concentration versus depth profiles of the defects show that dissociation of Fe-B occurs in the depletion region and capacitance-voltage measurements unveil a decrease in the charge carrier concentration due to passivation of B. These quantitative observations imply strongly that H promotes dissociation of Fe-B releasing Fei whereas no detectable passivation of Fe-B or Fei by H occurs.


1998 ◽  
Vol 510 ◽  
Author(s):  
Shabih Fatima ◽  
Jennifer Wong-Leung ◽  
John Fitz Gerald ◽  
C. Jagadish

AbstractSubthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for the extended defects. Also the mass dependence on the damage evolution has been observed, where rod-like defects are observed in the case of Si and (rod-like defects and loops) for Ge and Sn despite the fact that peak concentration of vacancies for Ge and Sn are normalized to the peak number of vacancies for Si.


1995 ◽  
Vol 378 ◽  
Author(s):  
R.R. Bilyalov ◽  
B.M. Abdurakhmanov

AbstractThe effect of hydrogen passivation on photovoltaic performance of 1 MeV electron irradiated polycrystalline cast silicon solar cells is described. These cells were processed on cast p-type boron doped polycrystalline silicon substrates using standard technology. Passivation was made by low-energy hydrogen ion implantation on the front side. Cells performance was measured as a function of fluence, and it was found that the hydrogenated cell had the higher radiation resistance.Defect behavior were studied using deep level transient spectroscopy and infra-red spectroscopy. It was shown that the concentration of vacancies (Ec −0,09 eV), divacancies (Ec −0,23 eV) and A-centers (Ec −0,18 eV) is significantly lower in hydrogenated samples. This consistency strengthens the belief that hydrogen interacts with vacancy-type defects to prevent formation of the secondary radiation defects. It is confirmed by IR-measurements.


1987 ◽  
Vol 65 (8) ◽  
pp. 966-971 ◽  
Author(s):  
N. Christoforou ◽  
J. D. Leslie ◽  
S. Damaskinos

CdS–CuInSe2 solar cells, which have an efficiency of 9%, have been studied by current–voltage, capacitance–voltage, and capacitance-transient measurements over the temperature range 90–380 K. Deep-level transient spectroscopy analysis of the capacitance transient measurements reveals one majority carrier trap with an activation energy of 0.70 ± 0.02 eV. Although the present experiment cannot establish definitely if the trap is in the CdS or CuInSe2 layer, arguments are presented that it is a hole trap in the p-type CuInSe2 layer. Current–voltage measurements indicate a reversible increase in the reverse-bias leakage current with increasing temperature above 300 K. Evidence is presented that suggests that the rectifying barrier height in the CdS–CuInSe2 solar cell decreases rapidly with temperature above 300 K. Capacitance versus voltage measurements suggest that the depiction layer being studied is primarily in the CuInSe2, but the temperature dependence of the ionized charge concentration N(x) cannot be totally explained although one possible cause is suggested.


1989 ◽  
Vol 160 ◽  
Author(s):  
K.L. Jiao ◽  
A.J. Soltyka ◽  
W.A. Anderson ◽  
S.M. Vernon

AbstractDeep level transient spectroscopy (DLTS), current-voltage- temperature (I-V-T), capacitance-voltage-temperature (C-V-T), C-T and photoreflectance spectroscopy (PRS) were used to compare the electrical properties of GaAs p-n junctions epitaxially grown by MOCVD on GaAs and Si substrates. EL2 was detected for both GaAs/GaAs and GaAs/Si structures. For GaAs/Si, a continuous distribution of trap levels was also observed which could be ascribed to misfit defects. I-V-T data revealed the saturation current of GaAs/Si diodes to be four orders in amplitude higher than for GaAs/GaAs ones. Different temperature dependences were found in saturation current density, barrier height and capacitance between the two structures. A multistep tunneling model is utilized in explaining the results for GaAs/Si. C-T measurements indicated the free carriers not to be frozen-out for GaAs/Si at the freeze-out temperature of GaAs/GaAs. A defect- induced bandgap tailing effect might be responsible for this effect, verified by PRS tests.


2009 ◽  
Vol 615-617 ◽  
pp. 397-400 ◽  
Author(s):  
Gaetano Izzo ◽  
Grazia Litrico ◽  
Andrea Severino ◽  
Gaetano Foti ◽  
Francesco La Via ◽  
...  

The defects produced by 7.0 MeV C+ irradiation in 4H-SiC epitaxial layer were followed by Deep Level Transient Spectroscopy, current-voltage measurements and Transmission Electron Microscopy in a large fluence range (109-51013 ions/cm2). At low fluence (109 -1010 ions/cm2), the formation of three main level defects located at 0.68 eV, 0.98 eV and 1.4 eV below the conduction band edge is detected. The trap concentration increases with ion fluence suggesting that these levels are associated to the point defects generated by ion irradiation. In this fluence range the leakage current of the diodes does not change. At higher fluence an evolution of defects occurs, as the concentration of traps at 0.68 eV and 1.4 eV decreases, while the intensity of the level at 0.98 eV remains constant. In this fluence range complex defects are formed and an increase of a factor five in the leakage current is measured.


2014 ◽  
Vol 1699 ◽  
Author(s):  
Per Lindberg ◽  
Vincent Quemener ◽  
Kristin Bergum ◽  
Jiantuo Gan ◽  
Bengt G. Svensson ◽  
...  

ABSTRACTAluminum doped ZnO (AZO) has been deposited on (100), (110) and (111) oriented n-type Si and on fused silica by atomic layer deposition (ALD). The films have been post deposition annealed in the temperature range 200-500 οC. The AZO films have been characterized by X-ray diffraction (XRD), Hall and transmittance measurements. Circular diodes have been fabricated from the AZO/Si structures and characterized by current-voltage (IV) and deep level transient spectroscopy (DLTS). The AZO films form Schottky junctions with the Si substrates for all the crystallographic orientations. It is established that after post deposition annealing the structure AZO/n-Si (110) is distinguished as the system with largest rectification.


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