scholarly journals Deep-level traps in lightly Si-doped n-GaN on free-standing m-oriented GaN substrates

AIP Advances ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 045311 ◽  
Author(s):  
H. Yamada ◽  
H. Chonan ◽  
T. Takahashi ◽  
T. Yamada ◽  
M. Shimizu
Keyword(s):  
Deep Level ◽  
Free Standing ◽  
Si Doped

Traps in Si-doped AlxGa1-xN Grown by Molecular Beam Epitaxy on Sapphire Characterized by Deep Level Transient Spectroscopy

2006 ◽  
Vol 955 ◽  
Author(s):  
Mo Ahoujja ◽  
S Elhamri ◽  
M Hogsed ◽  
Y. K. Yeo ◽  
R. L. Hengehold
Keyword(s):  
Molecular Beam Epitaxy ◽  
Deep Level Transient Spectroscopy ◽  
Molecular Beam ◽  
Deep Level ◽  
Unknown Origin ◽  
Shallow Donor ◽  
Related Point ◽  
Line Defects ◽  
Si Doped ◽  
Transient Spectroscopy

ABSTRACTDeep levels in Si doped AlxGa1−xN samples, with Al mole fraction in the range of x = 0 to 0.30, grown by radio-frequency plasma activated molecular beam epitaxy on sapphire substrates were characterized by deep level transient spectroscopy (DLTS). DLTS measurements show two significant electron traps, P1 and P2, in AlGaN at all aluminum mole fractions. The electron trap, P2, appears to be a superposition of traps A and B , both of which are observed in GaN grown by various growth techniques and are thought to be related to VGa-shallow donor complexes. Trap P1 is related to line defects and N-related point defects. Both of these traps are distributed throughout the bulk of the epitaxial layer. An additional trap P0 which was observed in Al0.20Ga0.80N and Al0.30Ga0.70N is of unknown origin, but like P1 and P2, it exhibits dislocation-related capture kinetics. The activation energy measured from the conduction band of the defects is found to increase with Al mole content, a behavior consistent with other III-V semiconductors.

Electrical and Optical Properties of Vanadium in Omvpe-Grown GaAs

1989 ◽  
Vol 145 ◽  
Author(s):  
W. S. Hobson ◽  
S. J. Pearton ◽  
V. Swaminathan ◽  
A. S. Jordan ◽  
Y. J. Kao ◽  
...  
Keyword(s):  
Deep Level ◽  
Vanadium Content ◽  
Epitaxial Layers ◽  
Electrical And Optical Properties ◽  
Vanadium Concentration ◽  
Co Doping ◽  
Undoped Material ◽  
Maximum Value ◽  
Si Doped ◽  
Transient Spectroscopy

AbstractThe electrical and photoluminescent properties of vanadium incorporated into GaAs epitaxial layers from a VO(OC2 H5)3 source during organometallic vapor phase epitaxy were examined. The vanadium concentration in the GaAs was controllably varied from 1016 to 1018 atoms cm−3. Deep level transient spectroscopy showed the presence of an electron trap at Ec – 0.15 eV which increased in concentration with vanadium content of the epitaxial layers. A maximum value of 8 × 1015 cm−3 for this trap was obtained. There were no midgap electron traps associated with vanadium. In intentionally Si-doped epitaxial layers, co-doping with vanadium was observed to have no effect in reducing the carrier density when the Si concentration was > 4 × 1016 cm−3. The net carrier concentration profiles resulting from 29 si implantation into GaAs containing 1018 cm−3of total V had sharper tails than for similar implantation into undoped material, indicating the presence of less than 1016 cm−3V-related acceptors. Photoluminescent spectra exhibited the characteristic V+3intracenter emission at 0.65∼0.75 eV. No other deep level photoluminescence was detected. For a V concentration of 1016 cm−3only 2.5 × 1013 cm−3was electrically active. Over the entire V concentration investigated this impurity was predominantly (≥99%) inactive.

Midgap electron traps in n-type GaAs epitaxial layers grown by the close-spaced vapor transport technique

1991 ◽  
Vol 69 (3-4) ◽  
pp. 407-411 ◽  
Author(s):  
T. Bretagnon ◽  
A. Jean ◽  
P. Silvestre ◽  
S. Bourassa ◽  
R. Le Van Mao ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Emission Rate ◽  
Deep Level ◽  
Vapor Transport ◽  
Epitaxial Layers ◽  
Spectroscopy Technique ◽  
Electron Traps ◽  
Si Doped ◽  
Transient Spectroscopy ◽  
Transport Technique

The deep-level transient spectroscopy technique was applied to the study of deep electron traps existing in n-type GaAs epitaxial layers that were prepared by the close-spaced vapor transport technique using three kinds of sources (semi-insulator-undoped, Zn-doped and Si-doped GaAs). Two midgap electron traps labelled ELCS1 and EL2 were observed in all layers regardless of the kind of source used. In addition, the effect of the electric field on the emission rate of ELCS1 is discussed and its identification to ETX2 and EL12 is suggested.

Carrier loss by rapid thermal-annealing in Si-doped GaAs grown by MOCVD (metal-organic chemical vapour deposition)

1991 ◽  
Vol 69 (3-4) ◽  
pp. 353-356
Author(s):  
C. Aktik ◽  
J. F. Currie ◽  
F. Bosse ◽  
R. W. Cochrane ◽  
J. Auclair
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Deep Level ◽  
Chemical Vapour ◽  
Organic Chemical ◽  
Before And After ◽  
Metal Organic ◽  
Si Doped

Si-doped GaAs epitaxial layers grown by metal-organic chemical vapour deposition exhibit substantial carrier density loss after rapid thermal annealing (RTA) at temperatures higher than 850 °C. Hall-effect, capacitance–voltage, deep-level transient spectroscopy, and secondary ion mass spectroscopy measurements were performed on samples before and after RTA. We show that the reduction of free-carrier concentration in the entire thickness of the epitaxial layer is accompanied by the deterioration of the mobility and the enhancement of donor-like deep-level concentration at 0.305 eV below the conduction band, which is in good agreement with the model of silicon donor neutralization by formation of neutral silicon–hydrogen complexes.

Rapid-Thermal-Processing Induced Deep Level Traps and their Spatial Distribution in MBE GaAs

1987 ◽  
Vol 92 ◽  
Author(s):  
Akio Kitagawa ◽  
Yutaka Tokuda ◽  
Akira Usami ◽  
Takao Wada ◽  
Hiroyuki kano
Keyword(s):  
Thermal Processing ◽  
Deep Level Transient Spectroscopy ◽  
Molecular Beam ◽  
Deep Level ◽  
Rapid Thermal Processing ◽  
Spatial Variations ◽  
Molecular Beam Epitaxial ◽  
Gaas Films ◽  
Si Doped ◽  
Transient Spectroscopy

ABSTRACTRapid thermal processing (RTP) using halogen lamps for a Si-doped molecular beam epitaxial (MBE) n-GaAs layers was investigated by deep level transient spectroscopy. RTP was performed at 700°C, 800°C and 900°C for 6 s. Two electron traps NI ( Ec-0.5-0.7eV) and EL2 (Ec - 0.82 eV) are produced by RTP at 800 and 900°C.The peculiar spatial variations of the Nl and EL2 concentration across the MBE GaAs films are observed. The larger concentrations of the trap N1 and EL2 are observed near the edge of the samples, and the minima of N1 and EL2 concentration lie between the center and the edge of the sample. It seems that these spatial variations of N1 and EL2 concentration are consistent with that of the thermal stress induced by RTP. Furthermore, the EL2 concentration near the edge of the sample is suppressed by the contact with the GaAs pieces on the edge around the sample during RTP.

Electronic Structure of Si Doped by Rare-Earth Yb3+

1993 ◽  
Vol 301 ◽  
Author(s):  
Shang Yuan Ren ◽  
John D. Dow
Keyword(s):  
Electronic Structure ◽  
Rare Earth ◽  
Spectral Density ◽  
Cluster Size ◽  
Deep Level ◽  
Deep Levels ◽  
Si Doped ◽  
Small Clusters ◽  
Vacancy Level

ABSTRACTThe electronic structure of Yb3+-doped Si is elucidated in terms of level repulsion between the Si vacancy's deep levels (and spectral density) and the Yb3+ levels, both for bulk Si and for small clusters. The 2F5/2 level of Yb3+ splits into a Γ8 level and a Γ6 level, with the Γ6 repelled most, by the nearby Γ6 (A1) level of the Si vacancy. The level-repulsion is either upwards or downwards in energy, depending on whether the Al-like vacancy level lies below or above this Yb3+ level. The 2F7/2 Yb 3+ level is split into Γ6, Γ7, and Γ8 sub-levels, all moving downwards in energy, with Γ6 moving most, again due to strong level repulsion from the nearby Al-like vacancy level, while the more-distant, higher-energy T2-like (Γ7 and Γ8) vacancy level produces a weaker repulsion. In small clusters, the Si-vacancy's wavefunctions and deep level energies are sensitive to cluster-size, and changes in them alter the level repulsion experienced by the Yb 3+ levels, even though the 4f electrons are localized.

Characterization of High Quality Continuous GaN Films Grown on Si-Doped Cracked GaN Template

2003 ◽  
Vol 764 ◽  
Author(s):  
C. B. Soh ◽  
J. Zhang ◽  
D.Z. Chi ◽  
S. J. Chua
Keyword(s):  
Plasma Etching ◽  
Edge Dislocation ◽  
Deep Level ◽  
Device Fabrication ◽  
Trap Level ◽  
Device Structure ◽  
High Quality ◽  
Si Doped ◽  
Additional Defect ◽  
Trap Levels

AbstractIn this paper, deep level defects in high quality continuous GaN films grown over a cracked Si-doped GaN template has been studied using digital deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). From TEM observation, it is found that the density of pure screw dislocations have been effectively suppressed while pure edge dislocations remained in substantial quantity. From DLTS measurement, trap levels at Ec -ET ∼ 0.11-0.12 eV, 0.24-0.27 eV, 0.60-0.63 eV were detected in the high quality GaN layer. DLTS measurement was also carried out on the underlying cracked Si-doped GaN template after the top high quality continuous GaN film was removed by plasma etching. An additional defect level at Ec-Et ∼ 0.37 eV was detected which we attributed to defect decoration at screw dislocation. Both the trap levels Ec-ET ∼ 0.24–0.27 eV, 0.60-0.63 eV are believed to originate from mixed screw/edge dislocation based on observation of the logarithmic capture behavior. Trap level at Ec -ET ∼ 0.24-0.27eV, however, experiences a more drastic increase in transient capacitance (i.e. in trap concentration) compared to that of Ec -ET ∼ 0.60-0.63 eV after plasma etching, illustrating that the latter is related to a higher proportion of edge dislocation. The 0.11-0.12 eV trap level, which exhibits an exponential capture kinetic, is believed to be related to nitrogen vacancies. This high quality continuous GaN layer can be used as a template to grow any device structure and the underneath cracked Si-doped GaN layer may help to release stress for the top continuous GaN layer. This can bring about a cracked free epilayer for subsequent device fabrication.

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