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.

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.

Acoustic spectroscopy and electrical characterization of SiO2/Si structures with ultrathin SiO2 layers formed by nitric acid oxidation

Open Physics ◽  
2009 ◽  
Vol 7 (2) ◽  
Author(s):  
Peter Bury ◽  
Hikaru Kobayashi ◽  
Masao Takahashi ◽  
Kentaro Imamura ◽  
Peter Sidor ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Deep Level ◽  
Electrical Characterization ◽  
Interface State ◽  
Hydrogen Atmosphere ◽  
Interface States ◽  
Acid Oxidation ◽  
Pure Nitrogen ◽  
Transient Spectroscopy ◽  
Nitric Acid Oxidation

AbstractUltrathin silicon dioxide (SiO2) layers formed on Si substrate with nitric acid have been investigated using both acoustic deep-level transient spectroscopy (A-DLTS) and electrical methods to characterize the interface states. The set of SiO2/Si structures formed in different conditions (reaction time, concentrations of nitric acid (HNO3), and SiO2 thickness [3–9 nm]) was prepared. The leakage current density was decreased by post-oxidation annealing (POA) treatment at 250°C in pure nitrogen for 1 h and/or post-metallization annealing (PMA) treatment at 250°C in a hydrogen atmosphere for 1 h. All structures of the set, except electrical investigation, current-voltage (I - V), and capacitance — voltage (C - V) measurements, were investigated using A-DLTS to find both the interface states distribution and the role of POA and/or PMA treatment on the interface-state occurrence and distribution. The evident decreases of interface states and shift of their activation energies in the structures with PMA treatment in comparison with POA treatment were observed in most of the investigated structures. The results are analyzed and discussed.

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.

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.

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.

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.

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