Summary Abstract: Deep level transient spectroscopy measurements on Si-doped AlGaAs/GaAs MODFET’s

Author(s):  
A. J. Valois
2006 ◽  
Vol 955 ◽  
Author(s):  
Mo Ahoujja ◽  
S Elhamri ◽  
M Hogsed ◽  
Y. K. Yeo ◽  
R. L. Hengehold

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.


1991 ◽  
Vol 69 (3-4) ◽  
pp. 407-411 ◽  
Author(s):  
T. Bretagnon ◽  
A. Jean ◽  
P. Silvestre ◽  
S. Bourassa ◽  
R. Le Van Mao ◽  
...  

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.


1987 ◽  
Vol 92 ◽  
Author(s):  
Akio Kitagawa ◽  
Yutaka Tokuda ◽  
Akira Usami ◽  
Takao Wada ◽  
Hiroyuki kano

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.


2005 ◽  
Vol 892 ◽  
Author(s):  
Mo Ahoujja ◽  
M Hogsed ◽  
Y. K. Yeo ◽  
R. L. Hengehold

AbstractSi doped GaN grown by molecular beam epitaxy on sapphire substrates were characterized by capacitance transient spectroscopy. Conventional deep level transient spectroscopy (DLTS) measurements displayed six deep level defects, labeled A1, A, B, C1, C, and D, with activation energy ranging from 0.20 to 0.82 eV below the conduction band. Based on the logarithmic dependence of the DLTS spectral peaks on the filling pulse width, it is deduced that the defects A, B, C, and D are concentrated in the vicinity of line dislocations. Double-correlation DLTS (DDLTS) measurements, on the other hand, showed that only defects A (0.82 eV) and D (0.22 eV) exhibited deep donor-like characteristics. Following a 1.0 MeV electron irradiation of the GaN sample, one radiation-induced peak, E, with activation energy less than 0.20 eV was observed in the DLTS spectrum. However, after annealing at 350 °C, this DLTS peak intensity was found to diminish significantly.


1987 ◽  
Vol 104 ◽  
Author(s):  
John W. Farmer ◽  
Harold P. Hjalmarson ◽  
G. A. Samara

ABSTRACTPressure dependent Deep Level Transient Spectroscopy (DLTS) experiments are used to measure the properties of the deep donors (DX-centers) responsible for the persistent photoconductivity effect in Si-doped AlGaAs. The sample dependence of the DLTS spectra shows evidence for a defect complex involved in the DX-center.


2002 ◽  
Vol 719 ◽  
Author(s):  
C. B. Soh ◽  
D. Z. Chi ◽  
H. F. Lim ◽  
S. J. Chua

AbstractIn this paper, deep level defects in undoped and Si–doped GaN have been studied using digital deep level transient spectroscopy. Common trap levels at Ec -ET ∼ 0.15-0.20 eV and 0.59-0.62 eV were detected for both undoped and Si-doped samples. For the doped samples, three additional defect levels at Ec-Et ∼ 0.11, 0.28, and 0.45 eV were detected. The concentration of the 0.15-0.20 eV was found to be much higher in undoped GaN that also shows higher dislocation density. Based on this correlation and the logarithmic capture behavior observed for this level, indicative of extended defect nature, we attribute the 0.15-0.20 eV level to dislocation related defects. On the other hand, the 0.28 and 0.45eV trap levels are tentatively attributed to Sirelated defects simply due to the fact that these two levels were observed only in Si-doped GaN. The 0.11eV trap level, which exhibits an exponential capture kinetic, is believed to be related to nitrogen vacancies.


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.


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