Interstitial Silicon Sink Efficiency of Dislocations Studied by Gold Diffusion in FZ and Cz Samples

1997 ◽  
Vol 469 ◽  
Author(s):  
G. Mariani ◽  
B. Pichaud ◽  
E. Yakimov
Keyword(s):  
Effective Activation Energy ◽  
Deep Level ◽  
Effective Diffusivity ◽  
Diffusion Annealing ◽  
Oxygen Precipitation ◽  
Dislocation Densities ◽  
Transient Spectroscopy ◽  
Gold Diffusion ◽  
Cantilever Bending

ABSTRACTThe substitutional gold concentration introduced by a diffusion step between 850 and 1000°C was measured by Deep Level Transient Spectroscopy (DLTS) both in FZ and Cz silicon containing different dislocation densities introduced by cantilever bending. The comparison, in the same sample, of dislocated and undislocated regions allows first the self interstitial (Sii) effective diffusivity and then the efficiency of dislocations as sinks for self-interstitials γto be measured. In FZ silicon, γ is quite independent of temperature whereas in Cz Si a remarkable temperature dependence was observed, with an effective activation energy of leV, which can be attributed to the release of dislocations by a thermally stimulated climbing mechanism from obstacles (oxygen segregation or precipitation). Increasing the gold diffusion annealing times for a given temperature (850°C) underlines once more the role of the oxygen precipitation in the samples.

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.

scholarly journals Deep levels in n-type Schottky and p+-n homojunction GaN diodes

2000 ◽  
Vol 5 (S1) ◽  
pp. 922-928
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Schottky Diodes ◽  
Yellow Luminescence ◽  
Arrhenius Behavior ◽  
Electron Level ◽  
Transient Spectroscopy ◽  
Electron And Hole Traps

The deep level spectra in both p+-n homojunction and n-type Schottky GaN diodes are studied by deep level transient spectroscopy (DLTS) in order to compare the role of the junction configuration on the defects found within the n-GaN layer. Both majority and minority carrier DLTS measurements are performed on the diodes allowing the observation of both electron and hole traps in n-GaN. An electron level at Ec−Et=0.58 and 0.62 V is observed in the p+-n and Schottky diodes, respectively, with a concentration of ∼3−4×1014 cm−3 and a capture cross section of ∼1−5×10−15 cm2. The similar Arrhenius behavior indicates that both emissions are related to the same defect. The shift in activation energy is correlated to the electric field enhanced-emission in the p+-n diode, where the junction barrier is much larger. The p+-n diode configuration allows the observation of a hole trap at Et−Ev=0.87 eV in the n-GaN which is very likely related to the yellow luminescence band.

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.

Lifetime Investigations of 4H-SiC PiN Power Diodes

2009 ◽  
Vol 615-617 ◽  
pp. 699-702 ◽  
Author(s):  
Sergey A. Reshanov ◽  
Wolfgang Bartsch ◽  
Bernd Zippelius ◽  
Gerhard Pensl
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Lifetime Measurements ◽  
Power Diodes ◽  
Defect Centers ◽  
Device Processing ◽  
Transient Spectroscopy ◽  
Base Range

Lifetime measurements are performed on 4H-SiC pin power diodes (6.5 kV). The lifetime values in the base range from 1.1 s to 2.1 s; these values demonstrate the high quality of the 4H-SiC epilayer and the optimized device processing. The observed lifetimes are correlated with deep defect centers detected by deep level transient spectroscopy. The role of the Z1/2-center as a lifetime killer is discussed.

DLTS Measurements on 4H-SiC JBS-Diodes with Boron Implanted Local P-N Junctions

2011 ◽  
Vol 679-680 ◽  
pp. 409-412
Author(s):  
Pavel A. Ivanov ◽  
Oleg Korolkov ◽  
Tat'yana P. Samsonova ◽  
Natalja Sleptsuk ◽  
Alexander S. Potapov ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Transient Spectroscopy ◽  
Dlts Spectra

In the present paper, 4H-SiC JBS diodes with "boron" p–n junctions have been investigated by means of deep-level transient spectroscopy (DLTS). The sign of the DLTS signal for all the 4H-SiC diodes under study, was positive. The "anomaly" of the DLTS spectra measured is apparently connected with the properties of "boron" p–n junctions. In particular, is presented the role of deep D-centers in recompensation of donors in the JBS diodes.

Influence of donor density in ZnO on ZnO–PrCoOx thin-film junctions: Role of O2 and Al dopant in varistors

1994 ◽  
Vol 9 (3) ◽  
pp. 669-673 ◽  
Author(s):  
Yoshihiko Yano ◽  
Yukihiko Shirakawa ◽  
Hisao Morooka
Keyword(s):  
Deep Level ◽  
Interface States ◽  
Clear Correlation ◽  
Zno Film ◽  
Donor Density ◽  
Zno Varistor ◽  
Capacitance Voltage ◽  
Single Grain ◽  
Transient Spectroscopy

ZnO/PrCoOx and ZnO/PrCoOx/ZnO junctions have been fabricated by sputtering as a model of a single grain boundary in a ceramic ZnO varistor. The relations between barrier parameters and varistor characteristics were investigated using voltage-current (V-I) capacitance-voltage (C-V), and deep-level transient spectroscopy (DLTS) measurements. The varistor voltage of the junctions increases as the donor density (ND) of the ZnO film decreases. The interface states vary according to the method of ZnO sputtering. A clear correlation has been established between the α value and the interface states. The highest α value is obtained when ND is ≃ 1018 cm−3, the interface level is 0.70 eV, and the breakdown voltage is 3–4 V. Oxygen is effective on control of ND in ZnO and the interface states. Al added as a dopant is also effective in terms of its ability to increase ND in ZnO. However, Al doping was found to degrade the interface states and increase the leakage current.

The Effect of Annealing on Argon Implanted Edge Terminations for 4H-SiC Schottky Diodes

1999 ◽  
Vol 572 ◽  
Author(s):  
A P Knights ◽  
D J Morrison ◽  
N G Wright ◽  
C M Johnson ◽  
A G O'Neill ◽  
...  
Keyword(s):  
Breakdown Voltage ◽  
Thermal Evolution ◽  
Deep Level ◽  
Schottky Diodes ◽  
Positron Annihilation Spectroscopy ◽  
Trap Level ◽  
Edge Termination ◽  
Low Temperature Annealing ◽  
Transient Spectroscopy

ABSTRACTThe edge termination of SiC by the implantation of an inert ion species is used widely to increase the breakdown voltage of high power devices. We report results of the edge termination of Schottky barrier diodes using 30keV Ar+ ions with particular emphasis on the role of postimplant, relatively low temperature, annealing. The device leakage current measured at 100V is increased from 2.5nA to 7μA by the implantation of 30keV Ar+ ions at a dose of 1×1015 cm−2. This is reduced by two orders of magnitude following annealing at 600°C for 60 seconds, while a breakdown voltage in excess of 750V is maintained. The thermal evolution of the defects introduced by the implantation was monitored using positron annihilation spectroscopy (PAS) and deep-level-transient spectroscopy (DLTS). While a concentration of open-volume defects in excess of 1×1019cm−3 is measured using PAS in all samples, electrically active trapping sites are observed at concentrations ∼1×1015cm−3 using DLTS. The trap level is well-defined at Ec−Et = 0.9eV.

Analysis of A-DLTS spectra of MOS structures with thin NAOS SiO2 layers

Open Physics ◽  
2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Peter Hockicko ◽  
Peter Bury ◽  
Peter Sidor ◽  
Hikaru Kobayashi ◽  
Masao Takahashi ◽  
...  
Keyword(s):  
Deep Level ◽  
Annealing Treatment ◽  
Interface States ◽  
Acid Oxidation ◽  
Electrical Measurements ◽  
External Bias ◽  
Transient Spectroscopy ◽  
Mos Structures ◽  
Dlts Spectra

AbstractA set of MOS structures with thin SiO2 layers prepared by nitric acid oxidation (NAOS) method was investigated using acoustic deep level transient spectroscopy (A-DLTS) to explain the role of annealing treatment (post-oxidation annealing (POA) and post-metallization annealing (PMA)) at different conditions on the distribution of interface states. The activation energies of interface states and the corresponding capture cross-section were calculated both from Arrhenius plots constructed for individual peaks of the A-DLTS spectra and applying the method of modeling of measured acoustic spectra. The energy distribution of the interface states was determined also from the dependence of acoustoelectric response signal (ARS) on the external bias voltage (U ac - V G curves). By comparing the A-DLTS spectra, U ac - V G characteristics and some electrical measurements (G-V, I-V curves) of investigated MOS structures with no treatment with those treated with POA and/or PMA, the role of individual treatments was observed. The definite decrease of the interface states in the structures with the PMA treatment in comparison with the POA treatment was confirmed too.

The Role of Charged Gap States in Light-Induced Degradation of Single-Junction a-Si:H Solar Cells

2004 ◽  
Vol 808 ◽  
Author(s):  
M. Zeman ◽  
V. Nádazdy ◽  
J.W. Metselaar
Keyword(s):  
Solar Cells ◽  
Deep Level ◽  
Spectral Response ◽  
State Density ◽  
Single Junction ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Hydrogenated Amorphous ◽  
Positively Charged

ABSTRACTComputer simulations of single-junction hydrogenated amorphous silicon (a-Si:H) solar cells with different thickness of the intrinsic layer were carried out in order to study the role of charge gap states in their light-induced degradation. It is demonstrated that it is the decrease of positively charged states above midgap, Dh, and the increase of neutral states around midgap,Dz, and negatively charged states below midgap, De in the intrinsic layer that result in a drop of performance of the solar cells due to light soaking. These changes in the gap states are in accordance with our recent experimental results from the charge deep-level transient spectroscopy on undoped a-Si:H. The experimentally observed changes in the dark and illuminated J-V curves and spectral response could not be simulated with the same set of input parameters by only increasing the defect-state density in the intrinsic layer.

An Investigation of Vacancy Concentrations in Bulk Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
Horst Zimmermann ◽  
H. Ryssel
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Vacancy Concentration ◽  
Gold Concentration ◽  
Bulk Silicon ◽  
Oxygen Precipitation ◽  
Float Zone ◽  
Transient Spectroscopy ◽  
Vacancy Concentrations

ABSTRACTA method will be presented, which allows the quantitative determination of distributions of single vacancies in bulk silicon. The method uses deep level transient spectroscopy (DLTS) measurements of the platinum or gold concentration after diffusion at a low temperature. An analytical expression allows the calculation of the vacancy concentration from the measured platinum or gold concentration. Vacancy concentrations vary at least from 2.0×1012 to 2.2×1014 cm3 in float zone silicon. The vacancy concentrations in Czrochalski (CZ) silicon are in the range of 4×1012 to 2×1013 cm3. Microwave photoconductive decay instead of DLTS allows much faster measurements of vacancy distributions on whole wafers. Furthermore, both methods allow the investigation of oxygen precipitation in CZ silicon.

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