Multi-Exponential Analysis of DLTS by Contin

1986 ◽  
Vol 69 ◽  
Author(s):  
Jun Morimoto ◽  
Tatsuo Kida ◽  
Toru Miyakawa
Keyword(s):  
Continuous Spectrum ◽  
Cross Sections ◽  
Emission Rate ◽  
Deep Level ◽  
Energy Levels ◽  
Three Dimensional ◽  
Deep Impurity ◽  
Junction Capacitance ◽  
Single Temperature ◽  
Single Exponential

AbstractDeep level transient spectroscopy (DLTS), which assumes a single exponential decay form for the transient junction capacitance, is the most commonly used method to characterize deep impurity levels in semiconductors. However conventional DLTS may lead to erroneous results if there are several closely spaced energy levels or the emission rate has a continuous spectrum. To overcome this difficulty a novel method named the multi-exponential analysis of DLTS by CONTIN (MEDLTS by CONTIN) is proposed. This method analyzes the emission rate to have a finite continuous spectrum S(λ) which appears in the transient junction capacitance C(t)=, by using the program “CONTIN” developed by Provencher in biophysics. Even if S(λ) includes two peaks at λ1 and λ2, those peaks can be distinguished for λ2/ λ1>2. As an example of the application of this method, deep levels in Si:Au were experimentally investigated. According to the three dimensional S(λ)-T2/λ-1/T representation, the single peak in the conventional DLTS was clarified to consist of two adjacent levels with activation energies and capture cross sections EB1=0.51eV, σB1=4.0×10−15cm2 and EB2=0.47eV, σB2=1.1×10−15cm2. With the assumption of the finite continuous spectrum S(λ) for the emission rate, MEDLTS by CONTIN permits one to get much information correctly. MEDLTS by CONTIN is superior to the conventional DLTS because it is a single-temperature scan, multi-exponential analysis instead of the conventional multi-temperature scan, single-exponential analysis.

Analysis of Emission Rate Measurements in a Material Showing a Meyer-Neldel- Rule

2003 ◽  
Vol 799 ◽  
Author(s):  
Richard S. Crandall
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Emission Rate ◽  
Deep Level ◽  
Entropy Change ◽  
Emission Data ◽  
Entropy Changes ◽  
Deep Traps ◽  
Transient Spectroscopy ◽  
Transition Entropy

ABSTRACTThis paper presents data showing a Meyer-Neldel rule (MNR) in InGaAsN alloys. It is shown that without this knowledge, significant errors can be made using Deep-Level Transient-Spectroscopy (DLTS) emission data to determine capture cross sections. The errors arise because of the neglect of significant transition entropy changes associated with multiphonon excitation of charge from deep traps. Ignoring the entropy change results in cross section values ranging over five orders-of-magnitude in InGaAsN alloys and 18 orders-of-magnitude in CuInGaSe alloys. Only by correctly accounting for the MNR and the accompanying entropy changes in analyzing the DLTS data will the correct value of the cross section be obtained.

Probing Metal Defects in CCD Image Sensors

1995 ◽  
Vol 378 ◽  
Author(s):  
William C. McColgin ◽  
J. P. Lavine ◽  
C. V. Stancampiano
Keyword(s):  
Cross Sections ◽  
Dark Current ◽  
Deep Level ◽  
Energy Levels ◽  
Image Sensors ◽  
Current Generation ◽  
Charge Coupled Device ◽  
Iron Nickel ◽  
Relationship Of ◽  
Ccd Image

AbstractWe have investigated the role of heavy metals in causing visible pixel defects in Charge Coupled Device (CCD) image sensors. Using a technique we call dark current spectroscopy, we can probe for deep-level traps in the active areas of completed image sensors with a sensitivity of 1 × 109 traps/cm3 or better. Analysis of histograms of dark current images from these sensors shows that the presence of traps causes quantization in the dark current. Different metal traps have characteristic dark current generation rates that can identify the contaminant trap. By examining the temperature dependence of the dark current generation, we have calculated the energy levels and generation cross sections for gold, iron, nickel, and cobalt. Our results show the relationship of these traps to the “white spot” defects reported for image sensors.

scholarly journals The Electronic States of Some Metal Impurities in Germanium

1982 ◽  
Vol 35 (1) ◽  
pp. 53 ◽  
Author(s):  
SJ Pearton
Keyword(s):  
Electrical Properties ◽  
Cross Sections ◽  
Energy Levels ◽  
Electronic States ◽  
Capture Cross ◽  
Deep Impurity ◽  
Impurity States ◽  
Metal Impurities ◽  
Capacitance Spectroscopy ◽  
Capture Cross Sections

Capacitance spectroscopy measurements of the energy levels and majority carrier capture cross sections of deep impurity states associated with S, Zn, Pb and Bi in Ge are presented. Similarities in the electrical properties of these elements with other deep impurities in Ge are discussed.

Deep Level Defect Characterization of MBE Grown Ingaas/Gaas Heterostructures.

1990 ◽  
Vol 209 ◽  
Author(s):  
W.R. Buchwald ◽  
J.H. Zhao ◽  
F.C. Rong
Keyword(s):  
Conduction Band ◽  
Cross Sections ◽  
Deep Level ◽  
Schottky Diodes ◽  
Energy Levels ◽  
Depth Profiling ◽  
Defect Characterization ◽  
Deep Level Defect ◽  
Transient Spectroscopy

ABSTRACTDeep level transient spectroscopy (DLTS) measurements have been performed on Schottky diodes fabricated on MBE grown InGaAs/GaAs heterostructures. The dominant electron trap in this material is found at a depth of 0.30eV below the GaAs conduction band and is believed to be the previously observed M3 defect. Two other defects, at depths of 0.50eV and 0.58eV below the GaAs conduction band, were also observed. Defect depth profiling shows the 0.50eV defect to be spatially locatednear the heterointerface. The 0.58eV defect is not observed near the heterointerface but is observed in large concentrations deep in the GaAs epilayer. Optical DLTS measurements reveal deep defects at 0.54eV and 0.31eV above the InGaAs valence band as well as a large, broad peak, most likely consisting of several energy levels with varying capture cross sections,located at the heterointerface. Two carrier accumulation peaks were also seen in the CV carrier profiling measurements and are suggested to be due to two heterointerface defects located at 0.68eV and 0.87eV below the GaAs conduction band.Thermally stimulated capacitance measurements also indicate minority hole emission in this n-InGaAs/N-GaAs heterostructure.

Electrical Properties of the Multilayer Structures Based on Ultrathin Diamond-Like Carbon Films

1996 ◽  
Vol 452 ◽  
Author(s):  
V. I. Polyakov ◽  
P. I. Perov ◽  
N. M. Rossukanyi ◽  
A. I. Rukovishnikov ◽  
A. V. Khomich ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Band Gap ◽  
Cross Sections ◽  
Deep Level ◽  
Energy Levels ◽  
Differential Resistance ◽  
Carbon Films ◽  
Multilayer Structures ◽  
Transient Spectra ◽  
Trapping Centers

AbstractThe electrical characteristics of multilayer structures based on amorphous ultrathin diamondlike carbon films were investigated including dynamic and quasi-static current-voltage characteristics, capacitance-voltage characteristics, deep level transient spectra. The effect of illumination and temperature on these characteristics was also investigated. For the multilayer structures composed of lower band gap amorphous carbon layers separated with higher band gap ones, there were observed well-defined regions of negative differential resistance and sharp 20-fold changes in capacitance at definite voltages. Activation energies, capture cross sections, and locations of trapping centers were defined. The effects observed are discussed in terms of trap-assisted tunneling and, also, in terms of resonant tunneling between energy levels in superlattices and charge filling of the quantum wells and trapping centers.

Metallic Impurities in n- and p- Type Silicon: Dlts Studies

1992 ◽  
Vol 262 ◽  
Author(s):  
Aditya Agarwal ◽  
Z. J. Radzimski ◽  
A. Buczkowski ◽  
F. Shimura ◽  
G. A. Rozgonyi
Keyword(s):  
Deep Level ◽  
Energy Levels ◽  
Simulated Data ◽  
Data Sets ◽  
Time Data ◽  
Type Silicon ◽  
Window Method ◽  
P Type ◽  
Rate Window ◽  
Single Exponential

ABSTRACTDeep level majority and minority carrier traps in p+/n and n+/p junction diodes have been investigated. The junctions were fabricated on n- and p- type silicon which was intentionally and uniformly doped with heavy metals Cr, Fe, Ni, and Au during Czochralski crystal growth. The activation energies of the traps in these devices has been determined using a computer based Deep Level Transient Spectroscopy system which stores and analyzes entire capacitance-time transients. The capacitance-time data sets have been analyzed using the standard rate-window method as well as by a new algorithm which is able to test for the existence of a single exponential. The new algorithm has shown that only one of the ten traps measured contained a single exponential. Rate-window analysis of all the data sets, however, yielded energy levels based on the expectation of a single-exponential, despite the inherent non-exponentiality of the transients. Implications on the reliability of results obtained by the rate window method have been discussed. Possible reasons for the observed non-exponentiality in the data have been suggested based on a study of simulated data.

Geological Field Sketches and Illustrations

2019 ◽  
Author(s):  
Matthew J. Genge
Keyword(s):  
Cross Sections ◽  
Earth Science ◽  
Three Dimensional ◽  
Worked Examples ◽  
Scientific Publications ◽  
Thin Sections ◽  
Geological Features ◽  
Different Types ◽  
The Subject

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.

scholarly journals Thermo-Hydraulic Performance of U-Tube Borehole Heat Exchanger with Different Cross-Sections

2021 ◽  
Vol 13 (6) ◽  
pp. 3255
Author(s):  
Aizhao Zhou ◽  
Xianwen Huang ◽  
Wei Wang ◽  
Pengming Jiang ◽  
Xinwei Li
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Heat Resistance ◽  
Cross Sections ◽  
Three Dimensional ◽  
Thermal Response ◽  
Transfer Efficiency ◽  
Cross Sectional ◽  
Heat Transfer Efficiency ◽  
Oval Tube

For reducing the initial GSHP investment, the heat transfer efficiency of the borehole heat exchange (BHE) system can be enhanced to reduce the number or depth of drilling. This paper proposes a novel and simple BHE design by changing the cross-sectional shape of the U-tube to increase the heat transfer efficiency of BHEs. Specifically, in this study, we (1) verified the reliability of the three-dimensional numerical model based on the thermal response test (TRT) and (2) compared the inlet and outlet temperatures of the different U-tubes at 48 h under the premise of constant leg distance and fluid area. Referent to the circular tube, the increases in the heat exchange efficiencies of the curved oval tube, flat oval tube, semicircle tube, and sector tube were 13.0%, 19.1%, 9.4%, and 14.8%, respectively. (3) The heat flux heterogeneity of the tubes on the inlet and outlet sides of the BHE, in decreasing order, is flat oval, semicircle, curved oval, sector, and circle shapes. (4) The temperature heterogeneity of the borehole wall in the BHE in decreasing order is circle, sector, curved oval, flat oval, and semicircle shapes. (5) Under the premise of maximum leg distance, referent to the heat resistance of the tube with a circle shape at 48 h, the heat exchange efficiency of the curved oval, flat oval, semicircle, and sector tubes increased 12.6%, 17.7%, 10.3%, and 7.8%, respectively. (6) We found that the adjustments of the leg distance and the tube shape affect the heat resistance by about 25% and 12%, respectively. (7) The flat-oval-shaped tube at the maximum leg distance was found to be the best tube design for BHEs.

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