Carbon-related Deep States in Compensated n-type and Semi-Insulating GaN:C and their Influence on Yellow Luminescence

2004 ◽  
Vol 831 ◽  
Author(s):  
A. Armstrong ◽  
D. Green ◽  
A. R. Arehart ◽  
U. K. Mishra ◽  
J. S. Speck ◽  
...  

ABSTRACTThe physical origin of the yellow luminescence in MBE-grown GaN co-doped with C and Si was investigated. Deep level optical spectroscopy (DLOS), deep level transient spectroscopy (DLTS), and photoluminescence (PL) were used to study the deep level spectrum as a function of C incorporation. In the absence of C co-doping, samples were n-type and demonstrated a weak yellow luminescence band, likely related to VGa. For increasing C co-doping, samples became semi-insulating concurrent with increased intensity of the yellow luminescence and the concentration of C-related deep acceptors. The DLOS results were used to develop a configuration-coordinate model for a C-related deep level with optical ionization energy of 3.0 eV and Franck-Condon shift of 0.4 eV that is consistent with the observed yellow luminescence and DLTS results. From these findings, a general model for independent mechanisms of the yellow luminescence related to VGa for n-type GaN and C for n-type and semi-insulating GaN:C:Si is discussed.

2000 ◽  
Vol 5 (S1) ◽  
pp. 922-928
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  

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.


1989 ◽  
Vol 146 ◽  
Author(s):  
X. Boddaert ◽  
D. Vuillaume ◽  
D. Stievenard ◽  
J.C. Bourgoin ◽  
P. Boher

ABSTRACTWe have studied the effect of an H2 plasma (150 W; 150°C; 10, 20, 50, 100 s) on unannealed and annealed (850°C, AsH3 atmosphere) LEC GaAs material. Using Deep Level Transient Spectroscopy, we have shown that the plasma induces a main bistable defect DO, which has two possible stable states Dl and D2. A complete determination of the corresponding Configuration Coordinate Diagram has been done. Finally, no correlation has been obtained between DO and the native defects EL6, EL3 and EL2. No passivation of the EL2 defect has been observed and the evolution of the D0 concentration results from the association of hydrogen with AsGa. These observations are in disagreement with the identification of EL2 with an isolated AsGa.


1988 ◽  
Vol 144 ◽  
Author(s):  
G. Marrakchi ◽  
G. Chaussemy ◽  
A. Laugier ◽  
G. Guillot.

ABSTRACTRapid Thermal Annealing (RTA) effects on generation or annihilation of deep levels in GaAs have been investigated by Deep Level Transient Spectroscopy (DLTS). Capping proximity technique using three annealing configurations are employed to anneal Liquid Encapsulated Czochralski (LEC) and Bridgman (B) substrates, or Vapor Phase Epitaxy (VPE) and Liquid Phase Epitaxy (LPE) layers. The RTA treatment is performed from 800 to 950°C for two annealing times ( 3 and 10s).The DLTS data show that the evolution of the native defects depends on the GaAs growth method and also the annealing configuration. We observe the appearance of two new electron traps named RL1 and RL2 induced by the RTA process which depend on the kind of substrate: RL1 and RL2 are created in LEC material while only RL1 is detected in B material. A general comparison of our results with others reported in the literature show that these new electron traps are related to the change of stoichiometry at the GaAs surface and also depend on the existence of specific native defects in the starting GaAs material. It is proposed that the creation of RL1 is related to the EL6 native defect and discuss a possible physical origin for this level. We also propose that RL2 and EL5 originate from the same defect and suggest the divacancy VGaVAs as a possible origin for this trap.


1999 ◽  
Vol 595 ◽  
Author(s):  
A. Hierro ◽  
D. Kwon ◽  
S. A. Ringel ◽  
M. Hansen ◽  
U. K. Mishra ◽  
...  

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.


1991 ◽  
Vol 223 ◽  
Author(s):  
A. Vaseashta ◽  
L. C. Burton

ABSTRACTKinetics of persistent photoconductivity, photoquenching, and thermal and optical recovery observed in low energy Ar+ bombarded on (100) GaAs surfaces have been investigated. Rate and transport equations for these processes were derived and simulated employing transport parameters, trap locations and densities determined by deep level transient spectroscopy. Excellent correlation was obtained between the results of preliminary simulation and the experimentally observed values. The exponential decay of persistent photoconductivity response curve was determined to be due to metastable electron traps with longer lifetime and is consistent with an earlier proposed model.


2002 ◽  
Vol 719 ◽  
Author(s):  
Masashi Kato ◽  
Masaya Ichimura ◽  
Eisuke Arai ◽  
Shigehiro Nishino

AbstractEpitaxial layers of 4H-SiC are grown on (0001) substrates inclined toward <1120> and <1100> directions. Defects in these films are characterized by deep level transient spectroscopy (DLTS) in order to clarify the dependence of concentrations and activation energies on substrate inclination. DLTS results show no such dependence on substrate inclination but show thickness dependence of the concentration.


Author(s):  
N. Chinone ◽  
Y. Cho ◽  
R. Kosugi ◽  
Y. Tanaka ◽  
S. Harada ◽  
...  

Abstract A new technique for local deep level transient spectroscopy (DLTS) imaging using super-higher-order scanning nonlinear dielectric microscopy is proposed. Using this technique. SiCVSiC structure samples with different post oxidation annealing conditions were measured. We observed that the local DLTS signal decreases with post oxidation annealing (POA), which agrees with the well-known phenomena that POA reduces trap density. Furthermore, obtained local DLTS images had dark and bright areas, which is considered to show the trap distribution at/near SiCVSiC interface.


2004 ◽  
Author(s):  
Souvick Mitra ◽  
Mulpuri V. Rao ◽  
N. Papanicolaou ◽  
K. A. Jones ◽  
M. Derenge

1997 ◽  
Vol 482 ◽  
Author(s):  
Z-Q. Fang ◽  
J. W. Hemsky ◽  
D. C. Look ◽  
M. P. Mack ◽  
R. J. Molnar ◽  
...  

AbstractA 1-MeV-electron-irradiation (EI) induced trap at Ec-0.18 eV is found in n-type GaN by deep level transient spectroscopy (DLTS) measurements on Schottky barrier diodes, fabricated on both metal-organic-chemical-vapor-deposition and hydride-vapor-phase-epitaxy material grown on sapphire. The 300-K carrier concentrations of the two materials are 2.3 × 1016 cm−3 and 1.3 × 1017 cm−3, respectively. Up to an irradiation dose of 1 × 1015 cm−2, the electron concentrations and pre-existing traps in the GaN layers are not significantly affected, while the EI-induced trap is produced at a rate of at least 0.2 cm−1. The DLTS peaks in the two materials are shifted slightly, possibly due to electric-field effects. Comparison with theory suggests that the defect is most likely associated with the N vacancy or Ga interstitial.


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