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.

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.

Electrical Characterization of N+-implanted n-type ZnO Single Crystals: p-n Homojunction and Deep Level Defects

2007 ◽  
Vol 1035 ◽  
Author(s):  
Qilin Gu ◽  
Xuemin Dai ◽  
Chi-Chung Ling ◽  
Shijie Xu ◽  
Liwu Lu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Thermal Evolution ◽  
Deep Level ◽  
Schottky Diodes ◽  
Control Sample ◽  
Electrical Characterization ◽  
Type Layer ◽  
Current Voltage ◽  
Transient Spectroscopy ◽  
Induced Defects

AbstractUnintentionally doped n-type ZnO single crystals were implanted by nitrogen ions with different fluences of 1013, 1014 and 1015 cm−2 respectively. ZnO p-n homojunction was successfully fabricated due to the formation of p-type layer after 650°C post-implantation annealing in air for 30 minutes. Further thermal evolution of deep level defects was studied through thermal annealing up to 1200°C. Electrical characterization techniques including current-voltage (I-V), capacitance-voltage (C-V), Deep Level Transient Spectroscopy (DLTS) and double-correlation DLTS (DDLTS) were used for investigating the control sample, all the as-implanted and annealed samples through Au/n-ZnO Schottky diodes as well as ZnO p-n junctions. Detailed electrical properties of fabricated devices and characteristics of implantation induced defects were analyzed based on plentiful DLTS spectra. Moreover, low-temperature photoluminescence experiments of all the as-implanted and annealed samples were performed and the correlation between results from electrical and optical characterizations was discussed.

Deep Levels in n-Type Schottky and p+-n Homojunction GaN Diodes

1999 ◽  
Vol 595 ◽  
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

AbstractThe 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 ∼3-4×1014cm−3 and a capture cross section of ∼1-5×10−15cm2. 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 Transient Spectroscopy (DLTS) Study of 4H-SiC Schottky Diodes and PiN Diodes

2019 ◽  
Vol 963 ◽  
pp. 516-519 ◽  
Author(s):  
Xiang Zhou ◽  
Gyanesh Pandey ◽  
Reza Ghandi ◽  
Peter A. Losee ◽  
Alexander Bolotnikov ◽  
...  
Keyword(s):  
Schottky Diode ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Schottky Diodes ◽  
High Energy ◽  
Pin Diode ◽  
Trap Level ◽  
Pin Diodes ◽  
Low Levels ◽  
Transient Spectroscopy

We have studied capacitance mode Deep Level Transient Spectroscopy (DLTS) of five 4H-SiC Schottky diode and PiN diode designs. Comparing with previous DLTS studies, we have identified four traps levels, Z1/2, EH1, EH3and EH5. Additionally, a new trap level, EH1, is prominent in blanket Al+and B+high-energy implanted samples but less so in mask-implanted samples. Al+implantation increases EH3(associated with silicon vacancy) and EH5, while B+implantation significantly reduces EH3. The Z1/2peak (associated with carbon vacancy) is reduced to very low levels after B+and Al+implantation.

DLTS AS A LOCAL PROBE OF CONCENTRATION AND DEPTH OF TRAP LEVELS

1994 ◽  
Vol 08 (13) ◽  
pp. 1765-1779 ◽  
Author(s):  
V. NÁDAŽDY ◽  
I. THURZO
Keyword(s):  
Deep Level ◽  
Direct Determination ◽  
Trap Depth ◽  
Pulse Mode ◽  
Detection Sensitivity ◽  
Trap Level ◽  
Charge Balance ◽  
Single Temperature ◽  
Transient Spectroscopy ◽  
Trap Levels

Complementarity of the capacitance and charge deep level transient spectroscopy (DLTS) is the idea which led us to an advanced method for profiling trap levels in semiconductors. This unifying approach to the space-charge spectroscopy, on grounds of applying the small-amplitude-filling pulse mode and evaluating the trapped charge balance, allows one to implement it in practice while using currently available instrumentation. A simple formalism is sufficient to obtain the demanded trap level depth. The usefulness of this method is demonstrated on bulk traps found in two different metal-insulator-semiconductor (MIS) capacitors. We propose also a new experimental technique providing the option of a direct determination of the trap depth from a single temperature scan. In addition, we found an expression for the relative detection sensitivity of the capacitance DLTS and justified quantitatively the earlier reported improved relative sensitivity of the charge transient spectroscopy.

Dislocations and Traps in MBE Grown Lattice Mismatched p- InGaAs/GaAs Layers on GaAs Substrates

1997 ◽  
Vol 484 ◽  
Author(s):  
A. Y. Du ◽  
M. F. Li ◽  
T. C. Chong ◽  
Z. Zhang
Keyword(s):  
Activation Energy ◽  
Layer Thickness ◽  
Deep Level ◽  
Photo Luminescence ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Trap Level ◽  
Nonradiative Recombination ◽  
Hole Trap ◽  
Transient Spectroscopy

AbstractDislocations and traps in MBE grown p-InGaAs/GaAs lattice-mismatched heterostructures are investigated by Cross-section Transmission Electron Microscopy (XTEM), Deep Level Transient Spectroscopy (DLTS) and Photo-luminescence (PL). The misfit dislocations and the threading dislocations observed by XTEM in different samples with different In mole fractions and different InGaAs layer thickness generally satisfy the Dodson-Tsao's plastic flow critical layer thickness curve. The threading dislocations in bulk layers introduce three hole trap levels HI, H2 and H5 with DLTS activation energies of 0.32 eV, 0.40 eV, 0.88 eV, respectively, and one electron trap El with DLTS activation energy of 0.54 eV. The misfit dislocations in relaxed InGaAs/GaAs interface induce a hole trap level H4 with DLTS activation energy between the range of 0.67–0.73 eV. All dislocation induced traps are nonradiative recombination centers which greatly degrade the optical property of the InGaAs/GaAs layers.

High Voltage Silicon Carbide Devices

1998 ◽  
Vol 512 ◽  
Author(s):  
B. Jayant Baliga
Keyword(s):  
Silicon Carbide ◽  
Breakdown Voltage ◽  
High Voltage ◽  
Impact Ionization ◽  
Voltage Drop ◽  
Schottky Diodes ◽  
Inversion Layer ◽  
Drift Region ◽  
Edge Termination ◽  
Silicon Devices

ABSTRACTProgress made in the development of high performance power rectifiers and switches from silicon carbide are reviewed with emphasis on approaching the 100-fold reduction in the specific on-resistance of the drift region when compared with silicon devices with the same breakdown voltage. The highlights are: (a) Recently completed measurements of impact ionization coefficients in SiC indicate an even higher Baliga's figure of merit than projected earlier. (b) The commonly reported negative temperature co-efficient for breakdown voltage in SiC devices has been shown to arise at defects, allaying concerns that this may be intrinsic to the material. (c) Based upon fundamental considerations, it has been found that Schottky rectifiers offer superior on-state voltage drop than P-i-N rectifiers for reverse blocking voltages below 3000 volts. (d) Nearly ideal breakdown voltage has been experimentally obtained for Schottky diodes using an argon implanted edge termination. (e) Planar ion-implanted junctions have been successfully fabricated using oxide as a mask with high breakdown voltage and low leakage currents by using a filed plate edge termination. (f) High inversion layer mobility has been experimentally demonstrated on both 6H and 4H-SiC by using a deposited oxide layer as gate dielectric. (g) A novel, high-voltage, normally-off, accumulation-channel, MOSFET has been proposed and demonstrated with 50x lower specific on-resistance than silicon devices in spite of using logic-level gate drive voltages. These results indicate that SiC based power devices could become commercially viable in the 21st century if cost barriers can be overcome.

“Recovery” Effect of Electron Induced Damage in 4H-SiC Schottky Diodes

2003 ◽  
Vol 792 ◽  
Author(s):  
A. Castaldini ◽  
A. Cavallini ◽  
L. Rigutti ◽  
F. Nava ◽  
P.G. Fuochi ◽  
...  
Keyword(s):  
Deep Level ◽  
Collection Efficiency ◽  
Schottky Diodes ◽  
Chemical Vapour ◽  
Liquid Nitrogen Temperature ◽  
Charge Collection Efficiency ◽  
Before And After ◽  
Transient Spectroscopy ◽  
Lower Temperature ◽  
Different Doses

ABSTRACTThe effects of electron irradiation on the defects associated electronic levels in Schottky diodes on 4H silicon carbide epilayers grown by chemical vapour deposition were investigated by Deep Level Transient Spectroscopy (DLTS) and Capacitance-Voltage (C-V) characteristics. These investigations were performed before and after irradiation with 8.6 MeV electrons at different doses. After irradiation four new traps with enthalpies equal to (Ec-0.23 eV), (Ec-0.39 eV), (Ec-0.63 eV) and (Ec-0.75 eV) were detected. Their thermal stability, a key point to determine their structure on the basis of recent theoretical and experimental results, was carefully investigated since it was earlier observed that during DLTS temperature runs up to 500 K a slight but significant recovery of a few irradiation-induced levels occurs. This effect was previously observed in literature for the level (Ec-0.70 eV) after thermal treatment at 500 °C [1], but the present results indicate that it involves more than a single level and is also effective at lower temperature. DLTS analyses were also performed from room temperature to liquid nitrogen temperature and vice versa up to 500 K.The annealing kinetics is reported and a few conclusions on the structure of the defects involved in the recovery are drawn. The correlation with the diode charge collection efficiency is also reported.

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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