Deep Level Defects in GaN Characterized by Capacitance Transient Spectroscopies

1995 ◽  
Vol 378 ◽  
Author(s):  
W. Gütz ◽  
N. M. Johnson ◽  
R. A. Street ◽  
H. Amano ◽  
I. Akasaki
Keyword(s):  
Thermal Activation ◽  
Deep Level ◽  
Schottky Diodes ◽  
Deep Levels ◽  
Electron Photoemission ◽  
Transient Spectroscopy ◽  
Capacitance Transient ◽  
Electronic Defects ◽  
Threshold Energies

AbstractElectronic defects in MOCVD-grown n-type GaN were characterized by conventional deep level transient spectroscopy (DLTS) and by photoemission capacitance transient spectroscopy (O-DLTS) performed on Schottky diodes. With DLTS two deep levels were detected with thermal activation energies for electron emission to the conduction band of 0.16 eV and 0.44 eV. With O-DLTS we demonstrate four new deep levels with optical threshold energies for electron photoemission of ∼ 0.87 eV, 0.97 eV, 1.25 eV and 1.45 eV. The O-DLTS apparatus and the measurement are discussed in detail. We also report characterization of the Au-GaN barrier height of the Schottky diode by internal photoemission.

Shallow and Deep Level Defects in GaN

1995 ◽  
Vol 395 ◽  
Author(s):  
W. Götz ◽  
N.M. Johnson ◽  
D.P. Bour ◽  
C. Chen ◽  
H. Liu ◽  
...  
Keyword(s):  
Deep Level ◽  
Variable Temperature ◽  
Shallow Donor ◽  
Deep Levels ◽  
Electron Photoemission ◽  
Hall Effect Measurements ◽  
Transient Spectroscopy ◽  
P Type ◽  
Capacitance Transient ◽  
Threshold Energies

ABSTRACTShallow and deep electronic defects in MOCVD-grown GaN were characterized by variable temperature Hall effect measurements, deep level transient spectroscopy (DLTS) and photoemission capacitance transient spectroscopy (O-DLTS). Unintentionally and Si-doped, n-type and Mg-doped, p-type GaN films were studied. Si introduces a shallow donor level into the band gap of GaN at ∼Ec - 0.02 eV and was found to be the dominant donor impurity in our unintentionally doped material. Mg is the shallowest acceptor in GaN identified to date with an electronic level at ∼Ev + 0.2 eV. With DLTS deep levels were detected in n-type and p-type GaN and with O-DLTS we demonstrate several deep levels with optical threshold energies for electron photoemission in the range between 0.87 and 1.59 eV in n-type GaN.

Characterization of Deep Levels in 3C-SiC by Optical-Capacitance-Transient Spectroscopy

2002 ◽  
Vol 719 ◽  
Author(s):  
Y. Nakakura ◽  
M. Kato ◽  
M. Ichimura ◽  
E. Arai ◽  
Y. Tokuda
Keyword(s):  
Cross Section ◽  
Thermal Activation ◽  
Deep Level ◽  
Threshold Energy ◽  
Thermal Activation Energy ◽  
Deep Levels ◽  
Optical Cross Section ◽  
Transient Spectroscopy ◽  
Capacitance Transient

AbstractAn optical-capacitance-transient spectroscopy (O-CTS) method was used to characterize the defects in 3C-SiC on Si. The O-CTS measurement enables us to estimate optical threshold energy and optical cross section for the defects. In the O-CTS spectrum, a peak was observed for photon energy hv larger than 0.5 eV. This peak was thought to be due to the ND1 center, which was also observed by deep level transient spectroscopy (DLTS) and found to have a thermal activation energy of 0.37 eV. The optical cross section for the center increased with hv for hv<0.6 eV and then decreased with increasing hv. The apparent optical threshold energy was about 0.47 eV. Another deep levels which have optical threshold energy of around 1.4 eV were also observed.

Transient Capacitance Characterization of Deep Levels in Undoped and Si-Doped GaN

2003 ◽  
Vol 764 ◽  
Author(s):  
S. Nakamura ◽  
P. Liu ◽  
M. Suhara ◽  
T. Okumura
Keyword(s):  
Chemical Vapor ◽  
Deep Levels ◽  
Yellow Luminescence ◽  
Capacitance Measurements ◽  
Transient Capacitance ◽  
Si Doped ◽  
Transient Spectroscopy ◽  
Capacitance Transient ◽  
Isothermal Capacitance Transient Spectroscopy

AbstractThe deep levels in both undoped and Si-doped GaN layer grown by metalorganic chemical vapor deposition have been characterized by photocapacitance and transient capacitance spectroscopy. The increase in the photocapacitance was observed in both GaN samples in the range of 1.8 to 2.2 eV. This is due to the photoionization of carriers from the deep levels associated with the yellow luminescence (YL). In addition, the transient capacitance measurements after the photoionization were also performed in the range of 1.8 to 3.4 eV. The notable transient of capacitance was observed at the photon energies of about 2.1 and 3.4 eV, the former could be associated with the change in the charge state of the YL center and latter might stem from some other defects capturing photogenerated carriers. By using the isothermal capacitance transient spectroscopy (ICTS) analysis, the ICTS peaks due to the deep levels associated with YL were detected at about t = 150 s in both GaN samples. In addition, another ICTS peak was detected only in the Si-doped GaN samples. It is considered that this peak is associated with the deep levels deeper than YL levels and the deeper levels originate from defects induced by Si doping.

Electrically Active Deep Levels in ScN

2001 ◽  
Vol 699 ◽  
Author(s):  
Florentina Perjeru ◽  
Xuewen Bai ◽  
Martin E. Kordesch
Keyword(s):  
Activation Energy ◽  
Vapor Deposition ◽  
Deep Level Transient Spectroscopy ◽  
Physical Vapor Deposition ◽  
Deep Level ◽  
Reactive Sputtering ◽  
Deep Levels ◽  
Si Substrates ◽  
Transient Spectroscopy

AbstractWe report the electronic characterization of n-ScN in ScN-Si heterojunctions using Deep Level Transient Spectroscopy of electrically active deep levels. ScN material was grown by plasma assisted physical vapor deposition and by reactive sputtering on commercial p+ Si substrates. Deep level transient spectroscopy of the junction grown by plasma assisted physical vapor deposition shows the presence of an electronic trap with activation energy EC-ET= 0.51 eV. The trap has a higher concentration (1.2–1.6 1013cm−3) closer to the ScN/Si interface. Junctions grown by sputtering also have an electronic trap, situated at about EC-ET= 0.90 eV.

Characterization of Deep Levels in High-Resistive 6H-SiC by Current Deep Level Transient Spectroscopy

2009 ◽  
Vol 615-617 ◽  
pp. 381-384 ◽  
Author(s):  
Masashi Kato ◽  
Kosuke Kito ◽  
Masaya Ichimura
Keyword(s):  
Temperature Dependence ◽  
Deep Level Transient Spectroscopy ◽  
Room Temperature ◽  
Deep Level ◽  
Deep Levels ◽  
Donor Level ◽  
Acceptor Level ◽  
Transient Spectroscopy ◽  
Lower Resistivity

We measured the temperature dependence of the electrical resistivity for two high-purity undoped 6H-SiC bulk wafers with resistivities of 1.5103 cm and 8.3108 cm at room temperature. We also characterized the deep levels affecting the semi-insulating property by current deep level transient spectroscopy (I-DLTS) and photo induced current level transient spectroscopy (PICTS) measurements. The activation energies of the resistivity were 0.11 eV and 0.59 eV for the samples with lower and higher resistivities, respectively. In I-DLTS and PICTS spectra, the sample with lower resistivity shows a donor level at Ec0.17 eV and two acceptor levels around Ec0.40 eV, while the sample with higher resistivity shows acceptor levels at Ec0.77 eV and Ev+0.46 eV. We calculated the temperature dependence of the resistivity with a model considering one donor level and one acceptor level based on parameters from I-DLTS peaks. We reproduced the experimental results only for the sample with lower resistivity. The acceptor level near the valence band needs to be considered to explain the resistivity for the sample with higher resistivity.

Deep Levels Observed in High-Purity Semi-Insulating 4H-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 455-458 ◽  
Author(s):  
Giovanni Alfieri ◽  
Tsunenobu Kimoto ◽  
Gerhard Pensl
Keyword(s):  
High Purity ◽  
Deep Level ◽  
Electrical Characterization ◽  
Current Mode ◽  
Deep Levels ◽  
Light Illumination ◽  
Hall Effect Measurements ◽  
Transient Spectroscopy ◽  
P Type

We report on the electrical characterization of high-purity semi-insulating 4H-SiC after annealing at temperatures between room temperature and 1700 oC by current-mode deep level transient spectroscopy (I-DLTS). I-V and Hall-effect measurements revealed that the investigated substrates possess p-type conductivity. Four deep levels were detected by I-DLTS with activation energies in the 0.15-1.29 eV range. We studied their thermal stability as well as their stability with respect to light illumination.

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