Deep Level Defect Studies in Mocvd-Grown InxGa1−sAs1−yNy Films Lattice-Matched to GaAs

1998 ◽  
Vol 535 ◽  
Author(s):  
Daewon Kwon ◽  
R. J. Kaplar ◽  
J. J. Boeckl ◽  
S. A. Ringel ◽  
A. A. Allerman ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Deep Level ◽  
Energy Levels ◽  
Resolution Limit ◽  
Defect States ◽  
Cross Sectional ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Lattice Matched ◽  
Dlts Spectra

AbstractDeep level defects in MOCVD-grown, unintentionally doped p-type InGaAsN films lattice matched to GaAs were investigated using deep level transient spectroscopy (DLTS) measurements. As-grown p-InGaAsN showed broad DLTS spectra suggesting that there exists a broad distribution of defect states within the band-gap. Moreover, the trap densities exceeded 1015 cm−3. Cross sectional transmission electron microscopy (TEM) measurements showed no evidence for threading dislocations within the TEM resolution limit of 107 cm−2. A set of samples was annealed after growth for 1800 seconds at 650 °C to investigate the thermal stability of the traps. The DLTS spectra of the annealed samples simplified considerably, revealing three distinct hole trap levels with energy levels of 0.10 eV, 0.23 eV, and 0.48 eV above the valence band edge with trap concentrations of 3.5 × 1014 cm−3, 3.8 × 1014 cm−3, and 8.2 × 1014 cm−3, respectively. Comparison of as-grown and annealed DLTS spectra showed that post-growth annealing effectively reduced the total trap concentration by an order of magnitude across the bandgap. However, the concentration of a trap with an energy level of 0.48 eV was not affected by annealing indicating a higher thermal stability for this trap as compared with the overall distribution of shallow and deep traps.

scholarly journals Electrical Characterization of Metastable Defects Introduced in GaN by Eu-Ion Implantation

2011 ◽  
Vol 679-680 ◽  
pp. 804-807 ◽  
Author(s):  
F. Danie Auret ◽  
Walter E. Meyer ◽  
M. Diale ◽  
P.J. Janse Van Rensburg ◽  
S.F. Song ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Deep Level ◽  
Energy Levels ◽  
Electrical Characterization ◽  
Defect States ◽  
First Order Kinetics ◽  
Transient Spectroscopy ◽  
Induced Defects ◽  
Transformation Processes

Gallium nitride (GaN), grown by HVPE, was implanted with 300 keV Eu ions and then annealed at 1000 oC . Deep level transient spectroscopy (DLTS) and Laplace DLTS (L-DLTS) were used to characterise the ion implantation induced defects in GaN. Two of the implantation induced defects, E1 and E2, with DLTS peaks in the 100 – 200 K temperature range, had DLTS signals that could be studied with L-DLTS. We show that these two defects, with energy levels of 0.18 eV and 0.27 eV below the conduction band, respectively, are two configurations of a metastable defect. These two defect states can be reproducibly removed and re-introduced by changing the pulse, bias and temperature conditions, and the transformation processes follow first order kinetics.

Ultra - Shallow p+/n Junction Formed by Plasma Ion Implantation

2000 ◽  
Vol 610 ◽  
Author(s):  
Sungkweon Baek ◽  
Chel-Jong Choi ◽  
Tae-Yeon Seong ◽  
Hyunsang Hwang ◽  
H. K. Kim ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Sheet Resistance ◽  
Deep Level ◽  
Junction Depth ◽  
Cross Sectional ◽  
Ultralow Energy ◽  
Ultrashallow Junctions ◽  
Plasma Doping ◽  
Order Of Magnitude ◽  
Transient Spectroscopy

AbstractWe have investigated the electrical characteristics, junction depth and defect of ultrashallow junctions formed by using a plasma doping procedure. Compared with ultralow energy boron ion implantation at 500eV, the plasma doping process exhibits both a shallow junction depth and a low sheet resistance. The junction depths of the plasma doped samples were 15 nm and 33 nm after annealing for 10s at 900 °C and 950 °C, respectively. For the same junction depth, the sheet resistance of the B2H6 plasma doped sample is an order of magnitude less than that of the 500eV B ion implanted sample. Based on cross-sectional transmission electron microscope (TEM) and deep level transient spectroscopy (DLTS) analysis, the defects formed by the B2H6 plasma doping process can be completely removed by annealing at 950 °C for 10s.

Spectrum of Defect States in Porous Organic Low-k Dielectric Films, Annealed in Argon and Nitrogen

2003 ◽  
Vol 766 ◽  
Author(s):  
V. Ligatchev ◽  
T.K.S. Wong ◽  
T.K. Goh ◽  
Rusli Suzhu Yu
Keyword(s):  
Deep Level ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Reverse Bias Voltage ◽  
Defect States ◽  
Single Side ◽  
Sandwich Type ◽  
Transient Spectroscopy ◽  
P Type ◽  
Spectrum Deconvolution

AbstractDefect spectrum N(E) of porous organic dielectric (POD) films is studied with capacitance deep-level-transient-spectroscopy (C-DLTS) in the energy range up to 0.7 eV below conduction band bottom Ec. The POD films were prepared by spin coating onto 200mm p-type (1 – 10 Δcm) single-side polished silicon substrates followed by baking at 325°C on a hot plate and curing at 425°C in furnace. The film thickness is in the 5000 – 6000 Å range. The ‘sandwich’ -type NiCr/POD/p-Si/NiCr test structures showed both rectifying DC current-voltage characteristics and linear 1/C2 vs. DC reverse bias voltage. These confirm the applicability of the C-DLTS technique for defect spectrum deconvolution and the n-type conductivity of the studied films. Isochronal annealing (30 min in argon or 60 min in nitrogen) has been performed over the temperature range 300°C - 650°C. The N(E) distribution is only slightly affected by annealing in argon. However, the distribution depends strongly on the annealing temperature in nitrogen ambient. A strong N(E) peak at Ec – E = 0.55 – 0.60 eV is detected in all samples annealed in argon but this peak is practically absent in samples annealed in nitrogen at Ta < 480°C. On the other hand, two new peaks at Ec – E = 0.12 and 0.20 eV appear in the N(E) spectrum of the samples annealed in nitrogen at Ta = 650°C. The different features of the defect spectrum are attributed to different interactions of argon and nitrogen with dangling carbon bonds on the intra-pore surfaces.

scholarly journals Correlation between Defects and Electrical Performances of Ion-Irradiated 4H-SiC p–n Junctions

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1966
Author(s):  
Domenico Pellegrino ◽  
Lucia Calcagno ◽  
Massimo Zimbone ◽  
Salvatore Di Franco ◽  
Antonella Sciuto
Keyword(s):  
Deep Level ◽  
Electrical Characterization ◽  
High Fluence ◽  
Defect States ◽  
Exponential Parameter ◽  
Current Voltage ◽  
Different Temperatures ◽  
In Series ◽  
Transient Spectroscopy ◽  
Fluence Range

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.

THERMAL CURRENTS FROM UNDOPED SEMI-INSULATING GaAs MONITORED BY CHARGE DEEP-LEVEL TRANSIENT SPECTROSCOPY

1995 ◽  
Vol 09 (23) ◽  
pp. 3099-3114
Author(s):  
I. THURZO ◽  
K. GMUCOVÁ ◽  
F. DUBECKÝ ◽  
J. DARMO
Keyword(s):  
Space Charge ◽  
Space Charge Region ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Energy Levels ◽  
Thermally Stimulated Currents ◽  
Metal Semiconductor Metal ◽  
Transient Spectroscopy ◽  
Electrical Bias

Metal-semiconductor-metal (MSM) devices prepared from crystalline undoped semi-insulating GaAs were investigated by charge deep-level transient spectroscopy (QDLTS), while exciting the devices by electrical bias pulses in dark. Unlike current concepts of the QDLTS response, thermally stimulated currents were integrated from devices with GaAs crystals thinned down to or below 200 µm and equipped with Au electrodes. Au-GaAs-Au structures on 230 µm thick crystals exhibited standard QDLTS response on either cooling or heating between 100 K and 250 K. It is concluded that a macroscopic space charge region of width ≈10−7 m is formed at the Au/GaAs interface, as the dominant energy levels became ionized. Obtained results on the peaks of the thermally stimulated charge were correlated with those of potentially identical peaks observed via optical admittance transient spectroscopy (OATS).

C-V and DLTS Analyses of Trap-Induced Graded Junctions: The Case of Al+ Implanted JTE p+n 4H-SiC Diodes

2009 ◽  
Vol 615-617 ◽  
pp. 469-472
Author(s):  
Filippo Fabbri ◽  
Francesco Moscatelli ◽  
Antonella Poggi ◽  
Roberta Nipoti ◽  
Anna Cavallini
Keyword(s):  
Depth Distribution ◽  
Minority Carrier ◽  
Deep Level ◽  
Forward Bias ◽  
Depth Range ◽  
Standard Configuration ◽  
Carrier Traps ◽  
Transient Spectroscopy ◽  
Graded Junction ◽  
Dlts Spectra

Capacitance versus Voltage (C-V) and Deep Level Transient Spectroscopy (DLTS) measurements of Al+ implanted p+n diodes with Al+ implanted Junction Termination Extension are here studied. These diodes present C-V characteristics like graded junction for low forward bias values, i.e. > 0.4 V , or like abrupt junctions for large reverse bias, i.e. between 0.4V and -10V. The depth range of the graded junction, computed by the capacitance values, is much larger than the simulated tail of the ion implanted Al+ profile. DLTS spectra have been measured both in injection and standard configuration and always show minority carrier traps in the temperature range 0-300K. Three are the minority carrier related peaks, one attributed to the Al acceptor and the others to the D and D1 defects. The depth distribution of these hole traps will be discussed with respect to the apparent carrier concentration, obtained by C-V analysis.

Z1/2- and EH6-Center in 4H-SiC: Not Identical Defects ?

2012 ◽  
Vol 717-720 ◽  
pp. 251-254 ◽  
Author(s):  
Bernd Zippelius ◽  
Alexander Glas ◽  
Heiko B. Weber ◽  
Gerhard Pensl ◽  
Tsunenobu Kimoto ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Field ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Schottky Contacts ◽  
Double Peak ◽  
Carbon Vacancy ◽  
High Concentrations ◽  
Transient Spectroscopy ◽  
Dlts Spectra

Deep Level Transient Spectroscopy (DLTS) and Double-correlated DLTS (DDLTS) measurements have been conducted on Schottky contacts fabricated on n-type 4H-SiC epilayers using different contact metals in order to separate the EH6- and EH7-centers, which usually appear as a broad double peak in DLTS spectra. The activation energy of EH6(EC- ET(EH6) = 1.203 eV) turns out to be independent of the electric field. As a consequence, EH6is acceptor-like according to the missing Poole-Frenkel effect. Therefore, it can be excluded that the EH6-center and the prominent acceptor-like Z1/2-center belong to different charge states of the same microscopic defect as theoretically suggested. It is proposed that EH6is a complex containing a carbon vacancy and another component available at high concentrations. The activation energy of EH7(EC- ET(EH7) = 1.58 eV) has been evaluated indirectly by fitting the DLTS spectra of the EH6/7double peak taking the previously determined parameters of EH6into account.

Hydrogen-Vacancy Complexes and their Deep States in n-Type Silicon

2015 ◽  
Vol 242 ◽  
pp. 163-168 ◽  
Author(s):  
Ilia L. Kolevatov ◽  
Frank Herklotz ◽  
Viktor Bobal ◽  
Bengt Gunnar Svensson ◽  
Edouard V. Monakhov
Keyword(s):  
Schottky Diode ◽  
Deep Level Transient Spectroscopy ◽  
Minority Carrier ◽  
Deep Level ◽  
Energy Levels ◽  
Depletion Region ◽  
Type Silicon ◽  
Oxygen Center ◽  
Hydrogen Vacancy ◽  
Transient Spectroscopy

The evolution of irradiation-induced and hydrogen-related defects in n-type silicon in the temperature range 0 – 300 °C has been studied by deep level transient spectroscopy (DLTS) and minority carrier transient spectroscopy (MCTS). Implantation of a box-like profile of hydrogen was performed into the depletion region of a Schottky diode to undertake the DLTS and MCTS measurements. Proportionality between the formation of two hydrogen-related deep states and a decrease of the vacancy-oxygen center concentration was found together with the appearance of new hydrogen-related energy levels.

Deep Levels in 4H Silicon Carbide Epilayers Induced by Neutron-Irradiation up to 1016 n/cm2

2006 ◽  
Vol 911 ◽  
Author(s):  
Anna Cavallini ◽  
Antonio Castaldini ◽  
Filippo Nava ◽  
Paolo Errani ◽  
Vladimir Cindro
Keyword(s):  
Deep Level ◽  
Collection Efficiency ◽  
Deep Levels ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
Temperature Range ◽  
Order Of Magnitude ◽  
Irradiation Level ◽  
Transient Spectroscopy ◽  
Induced Defects

AbstractWe investigated the electronic levels of defects introduced in 4H-SiC &#945;-particle detectors by irradiation with 1 MeV neutrons up to a fluence equal to 8x1015 n/cm2. As well, we investigated their effect on the detector radiation hardness. This study was carried out by deep level transient spectroscopy (DLTS) and photo-induced current transient spectroscopy (PICTS). As the irradiation level approaches fluences in the order of 1015 n/cm2, the material behaves as highly resistive due to a very great compensation effect but the diodes are still able to detect with a acceptably good charge collection efficiency (CCE) equal to 80%. By further increasing fluence, CCE decreases reaching the value of &#8776; 20% at fluence of 8x1015 n/cm2.The dominant peaks in the PICTS spectra occur in the temperature range [400, 700] K. Enthalpy, capture cross-section and order of magnitude of the density of such deep levels were calculated. In the above said temperature range the deep levels associated to the radiation induced defects play the key role in the degradation of the CCE. Two deep levels at Et = 1.18 eV and Et = 1.50 eV are likely to be responsible of such dramatic decrease of the charge collection efficiency. These levels were reasonably associated to an elementary defect involving a carbon vacancy and to a defect complex involving a carbon and a silicon vacancy, respectively.

Dlts and CV Analysis of Doped and N-Implanted GaN

1996 ◽  
Vol 423 ◽  
Author(s):  
D. Haase ◽  
M. Schmid ◽  
A. Dörnen ◽  
V. Härle ◽  
H. Bolay ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Deep Level ◽  
Implantation Dose ◽  
Nitrogen Implantation ◽  
Capacitance Voltage ◽  
Defect Levels ◽  
Transient Spectroscopy ◽  
Additional Defect ◽  
Cv Measurements ◽  
Dlts Spectra

AbstractWe studied by deep level transient spectroscopy (DLTS) and capacitance-voltage (CV) measurements the effects of doping (Zn, S), nitrogen implantation and annealing of n-type GaN grown on sapphire by MOVPE. The DLTS spectra of the as grown samples show two defect levels which are assumed to be identical with recently reported levels [10, 11]. In N-implanted GaN a third level is introduced which is not detectable in our as grown samples. This levels concentration follows the increasing N-implantation density. The depth profiles of its concentration correlate with the distribution of implantation defects expected from Monte-Carlo simulation. After annealing at 900°C for 60s the additional defect level vanishes. The DLTS spectrum then resembles those of annealed as grown samples. The n-type carrier concentration (CV measurements) increases in samples with low N-implantation dose. This implantation effect can be removed also with the RTA step. The increasing carrier concentration provides evidence that the N vacancy is a donor in GaN. For Zn and S doped GaN deep defect levels has been found, which are reported here.

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