Characterization of the potential well of a deep-level defect using field dependence of the thermal carrier emission rate

AbstractWe report on the electrical properties of defects as determined by deep level transient spectroscopy (DLTS) introduced in epitaxially grown n-GaN by 2.0 MeV protons and 5.4 MeV He-ions. After He-ion bombardment three electron traps ER3 (Ec - 0.196 eV), ER4 (Ec - 0.78 eV), and ER5 (Ec - 0.95 eV) were introduced uniformly in the region profiled by DLTS with introduction rates of 3270 ± 200, 1510 ± 300, and 3030 ± 500 cm-1 respectively. Capture cross section measurements revealed that the electron capture kinetics of ER5 is similar to that of a line defect. A defect with similar electronic properties as ER3 is observed after 2.0 MeV proton irradiation. The emission rate of ER3 depends on the electric field strength in the space-charge region. This emission rate is modelled according to the Poole-Frenkel distortion of a square well with a radius of 20 ± 2 Å or alternatively, a Gaussian well with a characteristic width of 6.0 ± 1 Å. Hence, we conclude that ER1 is a point defect which appears to have an acceptor like character. Two additional electron traps, ER1 (Ec -0.13 eV) and ER2 (Ec - 0.16eV) with introduction rates of 30 ± 10 and 600 ± 100 cm-1 not thusfar observed after electron or He-ion bombardment were observed after proton irradiation.

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Non-Contact, No Wafer Preparation Deep Level Transient Spectroscopy (DlTS) Based on Surface Photovoltage (SPV)

MRS Proceedings ◽

10.1557/proc-261-217 ◽

1992 ◽

Vol 261 ◽

Cited By ~ 1

Author(s):

Jacek Lagowski ◽

Piotr Edelman ◽

Mark Dexter

Keyword(s):

Emission Rate ◽

Thermal Emission ◽

Deep Level ◽

Surface States ◽

Deep Level Defect ◽

Recombination Lifetime ◽

Experimental Implementation ◽

Transient Spectroscopy ◽

Rate Window ◽

Minority Carriers

ABSTRACTThis work reports on the theoretical modeling and experimental investigation of isothermal SPV-DLTS based on the rate window concept. Experimental implementation of the technique is done using computer analysis of the SPV transients after ceasing the illumination. The transient involves two processes – a recombination of excess minority carriers and a thermal emission of carriers trapped by surface states and bulk defects. The later process is the key one for deep level defect determination.The upper limit for the measurable deep level emission rate is provided by the recombination lifetime. This limit often exceeds, by orders of magnitude, the standard 103 s−1 limit in capacitance DLTS. The sensitivity of SPV-DLTS is of the same order as that of optical capacitance DLTS.

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Electric-Field-Enhanced Thermal Emission from Osmium-Related Deep Level in n-GaAs

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.46.73 ◽

2006 ◽

Vol 46 ◽

pp. 73-78

Author(s):

M. Zafar Iqbal ◽

A. Majid ◽

Armin Dadgar ◽

D. Bimberg

Keyword(s):

Electric Field ◽

Field Dependence ◽

Emission Rate ◽

Thermal Emission ◽

Deep Level ◽

Chemical Vapour ◽

Organic Chemical ◽

Significant Shift ◽

Field Range ◽

Vapour Phase Epitaxy

Deep-level defects related with 5d transition metal, osmium (Os) have been studied in ntype GaAs. Os has been incorporated in epitaxial n-GaAs layers in situ, during growth by lowpressure metal-organic chemical vapour phase epitaxy (MOVPE) technique. Mesa p+nn+ junction diodes are fabricated for investigations by deep level transient spectroscopy (DLTS). Two deeplevel peaks, observed in majority carrier (electron) emission spectra, Os1 and Os2, show a significant shift in peak positions to lower temperatures with the applied junction reverse bias, demonstrating enhancement of the thermal emission rate by the junction electric field. Doublecorrelation DLTS (DDLTS) measurements have been employed for accurate quantitative investigations of the observed field dependence. However, in view of the relatively small concentration of the deep level Os1, this technique is found to yield reliable data only for the deep level corresponding to the dominant peak, Os2. Detailed data have been obtained on the field effect for Os2, extending over junction electric field values 3 x 106 V/m - 1.2 x 107 V/m. The measured emission rate signatures show a reduction of the thermal activation energy from 0.48 eV to 0.21 eV for Os2 over this electric field range. Analysis of the data in terms of the recent theoretical work on field dependence indicates that Os2 is associated with a substitutional Os donor.

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Electrical Characterization of Defects Introduced In n-GaN During High Energy Proton and He-Ion Irradiation

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300003124 ◽

1999 ◽

Vol 4 (S1) ◽

pp. 606-611 ◽

Cited By ~ 1

Author(s):

S. A. Goodman ◽

F. D. Auret ◽

F. K. Koschnick ◽

J.-M. Spaeth ◽

B. Beaumont ◽

...

Keyword(s):

Proton Irradiation ◽

Emission Rate ◽

Ion Irradiation ◽

Deep Level ◽

Electrical Characterization ◽

Ion Bombardment ◽

High Energy ◽

Electron Traps ◽

Transient Spectroscopy

We report on the electrical properties of defects as determined by deep level transient spectroscopy (DLTS) introduced in epitaxially grown n-GaN by 2.0 MeV protons and 5.4 MeV He-ions. After He-ion bombardment three electron traps ER3 (Ec − 0.196 eV), ER4 (Ec − 0.78 eV), and ER5 (Ec − 0.95 eV) were introduced uniformly in the region profiled by DLTS with introduction rates of 3270 ± 200, 1510 ± 300, and 3030 ± 500 cm−1 respectively. Capture cross section measurements revealed that the electron capture kinetics of ER5 is similar to that of a line defect. A defect with similar electronic properties as ER3 is observed after 2.0 MeV proton irradiation. The emission rate of ER3 depends on the electric field strength in the space-charge region. This emission rate is modelled according to the Poole-Frenkel distortion of a square well with a radius of 20 ± 2 Å or alternatively, a Gaussian well with a characteristic width of 6.0 ± 1 Å. Hence, we conclude that ER1 is a point defect which appears to have an acceptor like character. Two additional electron traps, ER1 (Ec −0.13 eV) and ER2 (Ec − 0.16eV) with introduction rates of 30 ± 10 and 600 ± 100 cm−1 not thusfar observed after electron or He-ion bombardment were observed after proton irradiation.

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

MRS Proceedings ◽

10.1557/proc-209-697 ◽

1990 ◽

Vol 209 ◽

Cited By ~ 1

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.

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Growth of GaN without Yellow Luminescence

MRS Proceedings ◽

10.1557/proc-395-625 ◽

1995 ◽

Vol 395 ◽

Cited By ~ 23

Author(s):

X. Zhang ◽

P. Kung ◽

D. Walker ◽

A. Saxler ◽

M. Razeghi

Keyword(s):

Vapor Deposition ◽

Metalorganic Chemical Vapor Deposition ◽

Deep Level ◽

Chemical Vapor ◽

Growth Conditions ◽

Native Defect ◽

Yellow Luminescence ◽

Gallium Vacancy ◽

Rich Condition

ABSTRACTWe report the growth and photoluminescence characterization of GaN grown on different substrates and under different growth conditions using metalorganic chemical vapor deposition. The deep-level yellow luminescence centered at around 2.2eV is attributed to native defect, most possibly the gallium vacancy. The yellow luminescence can be substantially reduced By growing GaN under Ga-rich condition or doping GaN with Ge or Mg.

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