Dislocations and Traps in MBE Grown Lattice Mismatched p- InGaAs/GaAs Layers on GaAs Substrates

1997 ◽  
Vol 484 ◽  
Author(s):  
A. Y. Du ◽  
M. F. Li ◽  
T. C. Chong ◽  
Z. Zhang

AbstractDislocations and traps in MBE grown p-InGaAs/GaAs lattice-mismatched heterostructures are investigated by Cross-section Transmission Electron Microscopy (XTEM), Deep Level Transient Spectroscopy (DLTS) and Photo-luminescence (PL). The misfit dislocations and the threading dislocations observed by XTEM in different samples with different In mole fractions and different InGaAs layer thickness generally satisfy the Dodson-Tsao's plastic flow critical layer thickness curve. The threading dislocations in bulk layers introduce three hole trap levels HI, H2 and H5 with DLTS activation energies of 0.32 eV, 0.40 eV, 0.88 eV, respectively, and one electron trap El with DLTS activation energy of 0.54 eV. The misfit dislocations in relaxed InGaAs/GaAs interface induce a hole trap level H4 with DLTS activation energy between the range of 0.67–0.73 eV. All dislocation induced traps are nonradiative recombination centers which greatly degrade the optical property of the InGaAs/GaAs layers.

Author(s):  
Nataliya Mitina ◽  
Vladimir Krylov

The results of an experiment to determine the activation energy of a deep level in a gallium arsenide mesastructure, obtained by the method of capacitive deep levels transient spectroscopy with data processing according to the Oreshkin model and Lang model, are considered.


1994 ◽  
Vol 08 (13) ◽  
pp. 1765-1779 ◽  
Author(s):  
V. NÁDAŽDY ◽  
I. THURZO

Complementarity of the capacitance and charge deep level transient spectroscopy (DLTS) is the idea which led us to an advanced method for profiling trap levels in semiconductors. This unifying approach to the space-charge spectroscopy, on grounds of applying the small-amplitude-filling pulse mode and evaluating the trapped charge balance, allows one to implement it in practice while using currently available instrumentation. A simple formalism is sufficient to obtain the demanded trap level depth. The usefulness of this method is demonstrated on bulk traps found in two different metal-insulator-semiconductor (MIS) capacitors. We propose also a new experimental technique providing the option of a direct determination of the trap depth from a single temperature scan. In addition, we found an expression for the relative detection sensitivity of the capacitance DLTS and justified quantitatively the earlier reported improved relative sensitivity of the charge transient spectroscopy.


2012 ◽  
Vol 717-720 ◽  
pp. 251-254 ◽  
Author(s):  
Bernd Zippelius ◽  
Alexander Glas ◽  
Heiko B. Weber ◽  
Gerhard Pensl ◽  
Tsunenobu Kimoto ◽  
...  

Deep Level Transient Spectroscopy (DLTS) and Double-correlated DLTS (DDLTS) measurements have been conducted on Schottky contacts fabricated on n-type 4H-SiC epilayers using different contact metals in order to separate the EH6- and EH7-centers, which usually appear as a broad double peak in DLTS spectra. The activation energy of EH6(EC- ET(EH6) = 1.203 eV) turns out to be independent of the electric field. As a consequence, EH6is acceptor-like according to the missing Poole-Frenkel effect. Therefore, it can be excluded that the EH6-center and the prominent acceptor-like Z1/2-center belong to different charge states of the same microscopic defect as theoretically suggested. It is proposed that EH6is a complex containing a carbon vacancy and another component available at high concentrations. The activation energy of EH7(EC- ET(EH7) = 1.58 eV) has been evaluated indirectly by fitting the DLTS spectra of the EH6/7double peak taking the previously determined parameters of EH6into account.


1992 ◽  
Vol 262 ◽  
Author(s):  
Subhasis Ghosh ◽  
Vikram Kumar

ABSTRACTPhoto-Deep Level Transient Spectroscopy with 1.38 eV light reveals a new level with thermal activation energy 0.2 eV of DX centers in silicon doped Alx Ga1-xAs (x = 0.26) for the first time. The observation of this level directly proves the negative-U properties of DX centers and the existence of thermodynamically metastable state DX.


1995 ◽  
Vol 379 ◽  
Author(s):  
K. Rammohan ◽  
D.H. Rich ◽  
A. Larsson

ABSTRACTThe temperature dependence of the cathodoluminescence (CL) originating from In0.21Ga0.79As/GaAs multiple quantum wells has been studied between 86 and 250 K. The CL intensity exhibits an Arrenhius-type dependence on temperature (T), characterized by two different activation energies. The spatial variations in activation energy caused by the presence of interfacial misfit dislocations is examined. The CL intensity dependence on temperature for T ≲ 150 K is controlled by thermally activated nonradiative recombination. For T ≳ 150 K the decrease in CL intensity is largely influenced by thermal re-emission of carriers out of the quantum wells.


2001 ◽  
Vol 699 ◽  
Author(s):  
Florentina Perjeru ◽  
Xuewen Bai ◽  
Martin E. Kordesch

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.


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.


2013 ◽  
Vol 205-206 ◽  
pp. 341-345 ◽  
Author(s):  
A.S. Loshachenko ◽  
Oleg F. Vyvenko ◽  
Oleg Kononchuk

The kinetics of hydrogen penetration through dislocation networks produced by silicon wafer bonding are investigated by means of reverse bias annealing (RBA) procedure. By using the combination of capacitance-voltage (CV) profiling of net-acceptor concentration and deep level transient spectroscopy (DLTS) the total concentration of H introduced in the samples during wet–chemical etching at room temperature was defined. Two processes with the different time constants τ1and τ2was found for the bonded sample. The slow process τ1with an activation energy of (1.25±0.13) eV was analogous to that in the reference sample and corresponded to the dissociation of boron-hydrogen pairs. The fast process τ2was found to exhibit a lower activation energy of (0.87±0.25) eV and was identified as the release of hydrogen bound at screw dislocations by their elastic strains.


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