DX CENTERS IN AlGaN

1999 ◽  
Vol 13 (11) ◽  
pp. 1363-1378 ◽  
Author(s):  
M. D. McCLUSKEY ◽  
C. G. VAN de WALLE ◽  
N. M. JOHNSON ◽  
D. P. BOUR ◽  
M. KNEISSL
Keyword(s):  
Deep Level ◽  
Far Infrared ◽  
Shallow Donor ◽  
Experimental Investigations ◽  
Nitride Semiconductors ◽  
Dx Centers ◽  
Free Carriers ◽  
Peak Intensity ◽  
Oxygen Impurities ◽  
Raman Peak Intensity

In this letter, recent theoretical and experimental investigations of DX centers in Al x Ga 1-x N are reviewed. Due to the technological importance of III–V nitride semiconductors, studies of deep-level defects in AlGaN have attracted a great deal of interest. Oxygen impurities form DX centers in GaN under hydrostatic pressure and in Al x Ga 1-x N alloys. For GaN under pressures greater than 20 GPa, the DX level emerges from the conduction band, leading to a decrease in the free-electron concentration. The localization of free carriers leads to a decrease in the far-infrared absorption and an increase in the LO Raman peak intensity. In Al x Ga 1-x N alloys, Hall effect and persistent photoconductivity measurements indicate that the DX state is energetically favorable for x>0.3. The experimental data for oxygen DX centers are in excellent agreement with first-principles calculations. Experiments have shown that silicon remains a shallow donor up to at least x=0.5 and theory indicates that it may remain shallow up to x=1.

Unusual Properties of the Red and Green Luminescence Bands in Ga-rich GaN

2004 ◽  
Vol 831 ◽  
Author(s):  
M. A. Reshchikov ◽  
H. Morkoç
Keyword(s):  
Low Temperatures ◽  
Molecular Beam ◽  
Deep Level ◽  
Shallow Donor ◽  
Time Resolved ◽  
Temperature Range ◽  
Peak Intensity ◽  
Integrated Intensity ◽  
Valence Bands ◽  
Increasing Temperature

ABSTRACTWe studied photoluminescence (PL) from deep-level defects in GaN grown under Garich conditions at relatively low temperatures (700–800°C) by molecular-beam epitaxy (MBE). The dominant features of PL spectrum are red and green bands peaking respectively at ∼1.8 and ∼2.35 eV. Both PL bands decay exponentially at low temperatures (15 – 100 K) after pulsed excitation. The characteristic lifetime for the red band decreases by almost two orders of magnitude from 110 to 2 μs with increasing temperature from 15 to 100 K, while its integrated intensity after each pulse remains nearly unchanged in the same temperature range due to an increase in the peak intensity in the time-resolved PL curve. The lifetime of the green band remained unchanged in this temperature range. We suggest that these PL bands are caused by transitions between excited and ground states of some deep defects rather than transitions involving a shallow donor, conduction or valence bands.

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.

Four-wave mixing in the far infrared from free carriers in n-type indium antimonide

1991 ◽  
Vol 16 (19) ◽  
pp. 1511 ◽  
Author(s):  
R. M. Hart ◽  
G. A. Rodríguez ◽  
A. J. Sievers
Keyword(s):  
Indium Antimonide ◽  
Far Infrared ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Free Carriers

scholarly journals Влияние нейтронного облучения на спектр дефектов с глубокими уровнями в GaAs, изготовленном методом жидкофазной эпитаксии в атмосфере водорода и аргона

2022 ◽  
Vol 56 (1) ◽  
pp. 53
Author(s):  
М.М. Соболев ◽  
Ф.Ю. Солдатенков
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Experimental Studies ◽  
Shallow Donor ◽  
Defect Clusters ◽  
Deep Traps ◽  
Capacitance Voltage ◽  
Before And After ◽  
Transient Spectroscopy ◽  
Different Doses

The results of experimental studies of capacitance– voltage characteristics, spectra of deep-level transient spectroscopy of graded high-voltage GaAs p+−p0−i−n0 diodes fabricated by liquid-phase epitaxy at a crystallization temperature of 900C from one solution–melt due to autodoping with background impurities, in a hydrogen or argon ambient, before and after irradiation with neutrons. After neutron irradiation, deep-level transient spectroscopy spectra revealed wide zones of defect clusters with acceptor-like negatively charged traps in the n0-layer, which arise as a result of electron emission from states located above the middle of the band gap. It was found that the differences in capacitance–voltage characteristics of the structures grown in hydrogen or argon ambient after irradiation are due to different doses of irradiation of GaAs p+−p0−i−n0 structures and different degrees of compensation of shallow donor impurities by deep traps in the layers.

Growth, Doping, Device Development and Characterization of CVD Beta-SiC Epilayers on Si(100) and Alpha-SiC(0001)

1987 ◽  
Vol 97 ◽  
Author(s):  
H. Kong ◽  
H. J. Kim ◽  
J. A. Edmond ◽  
J. W. Palmour ◽  
J. Ryu ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Elevated Temperatures ◽  
Deep Level ◽  
Schottky Diodes ◽  
Free Carriers ◽  
Device Development ◽  
Post Annealing ◽  
P Type ◽  
Sic Films

ABSTRACTMonocrystalline β-SiC films have been chemically vapor deposited on Si(100) and c-SiC(0001) at 1660K-1823K and 0.1 MPa using SiH4 and C2H4 carried in H2. Films grown directly on Si(100) contained substantial concentrations of dislocations, stacking faults and antiphase boundaries (APB); those on α-SiC(0001) contained double positioning boundaries. Both the APBs and the double positioning boundaries were eliminated by using off-axis orientations of the respective substrates. Films produced on Si(100) have also been doped during growth and via ion implantation with B or Al (p-type) or P or N (n-type) at LN, room and elevated temperatures. Results from the former procedure showed the ionized dopant/total dopant concentration ratios for N, P, B and Al to be 0.1, 0.2, 0.002 and 0.01, respectively. The solubility limits of N, P and B at 1660K were determined to be ∼ 2E20, 1E18 and 8E18 cm−3, respectively; that of Al exceeds 2E19 cm−3. High temperature ion implantation coupled with dynamic and post annealing resulted in a markedly reduced defect concentration relative to that observed in similar research at the lower temperatures. Schottky diodes, p-n junctions, and MOSFET devices have been fabricated. The p-n junctions have the characteristics of insulators containing free carriers and deep level traps. The MOSFETs show very good I-V characteristics up to 673K, but have not been optimized.

Shallow-donor impurities in indium selenide investigated by means of far-infrared spectroscopy

1992 ◽  
Vol 46 (8) ◽  
pp. 4607-4616 ◽  
Author(s):  
J. Martinez-Pastor ◽  
A. Segura ◽  
C. Julien ◽  
A. Chevy
Keyword(s):  
Infrared Spectroscopy ◽  
Far Infrared ◽  
Shallow Donor ◽  
Indium Selenide ◽  
Far Infrared Spectroscopy

Deep Level Characterization of LP-MOCVD Grown Al0.48In0.52As

1993 ◽  
Vol 325 ◽  
Author(s):  
F. Ducroquet ◽  
G. Guillot ◽  
K. Hong ◽  
C.H. Hong ◽  
D. Pavlidis ◽  
...  
Keyword(s):  
Deep Level ◽  
Shallow Donor ◽  
Electrical Characteristics ◽  
Oxygen Contamination ◽  
Deep Donor ◽  
Low Pressure Mocvd ◽  
Different Origins ◽  
Inp Substrates ◽  
Preferential Incorporation

AbstractDeep levels in unintentionally doped A10. 48In0.52As layers epitaxially grown on InP substrates by low-pressure MOCVD have been investigated as a function of growth temperature (Tg ranging from 570 to 690°C). Two different origins for the residual carrier concentration are deduced depending on Tg: i) low growth temperatures favor the creation of a deep donor located at Ec-(0.13±0.04)eV; ii) At higher Tg, a preferential incorporation of a shallow donor occurs, which can be attributed to silicon by SIMS measurements. The oxygen contamination deduced by SIMS and the electrical characteristics of the AlInAs layers do not appear to be correlated.

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