Defect Levels in the Near-Surface Region of 2.0 MeV 16O+ Ion Implanted n-GaAs.

1989 ◽  
Vol 163 ◽  
Author(s):  
C.C. Tin ◽  
P.A. Barnes ◽  
T.T. Bardin ◽  
J.G. Pronko

AbstractMeV ion implantation in GaAs is known to cause amorphization of the region at the end of the ion range. The near-surface region, however, is still crystalline albeit heavily compensated. We have carried out deep level transient spectroscopy (DLTS) studies of the defect levels in the near—surface region of n—GaAs samples implanted with different doses of 2.0 MeV 16O+ ions.A comparison between the defect structures in the original and the implanted samples shows that implantation produced a broad range of defect levels ranging from 0.58 to 0.3 eV from the conduction band edge. This broad range of defects has an unusually large capture cross—section. The intensities of the DLTS peaks increase with the dose of 160+ ions. The presence of EL2, which was present in the original samples, was not observed in the implanted samples.Results from measurements made on samples that have been implanted at 200°C and on implanted samples subjected to rapid thermal annealing will also be discussed.

2003 ◽  
Vol 799 ◽  
Author(s):  
P. N. K. Deenapanray ◽  
M. Krispin ◽  
W. E. Meyer ◽  
H. H. Tan ◽  
C. Jagadish ◽  
...  

ABSTRACTImpurity-free disordering (IFD) of GaAs and AlxGa1-xAs epitaxial layers using SiOx capping in conjunction with annealing was studied by deep level transient spectroscopy (DLTS) and capacitance-voltage (C-V) measurements. Three dominant electron traps S1 (EC– 0.23 eV), S2* (EC– 0.53 eV), and S4 (EC– 0.74 eV) are created in disordered n-type GaAs. The electron emission rate of S1 is enhanced in the presence of an externally applied electric field. We propose that S1 is a defect that may involve As-clustering or a complex of arsenic interstitials, Asi, and the arsenic-antisite, AsGa. S2* is shown to be the superposition of two defects, which may be VGa-related. S4 is identified as the defect EL2. Our preliminary results indicate that the same set of defects is created in disordered n-type AlxGa1-xAs, with S1 pinned to the conduction band edge, while S2* and S4 are pinned relative to the Fermi level. In contrast to disordering in n-type GaAs, IFD of p-type GaAs results in the pronounced increase in the free carrier concentration in the near-surface region of the disordered layer. Two electrically active defects HA (EV+ 0.39 eV) and HB2 (EV+ 0.54 eV), which we have attributed to Cu- and Asi/AsGa-related levels, respectively, are also observed in the disordered p-GaAs layers. IFD causes segregation of Zn dopant atoms and Cu towards the surface of IFD samples. This atomic relocation process poses serious limitations regarding the application of IFD to the band gap engineering of doped GaAs-based heterostructures.


2005 ◽  
Vol 108-109 ◽  
pp. 373-378 ◽  
Author(s):  
Marie-Laure David ◽  
Eddy Simoen ◽  
Cor Claeys ◽  
V.B. Neimash ◽  
M. Kras'ko ◽  
...  

Different group IV impurities (Pb, C, and Sn) have been introduced in the melt during the growth of n-type Czochralski silicon. The samples have been irradiated with 1 MeV electrons to a fluence of 4x1015cm-2. The irradiation-induced defects have been studied by Deep Level Transient Spectroscopy (DLTS). It is shown that the formation of one of the irradiation-induced deep level is avoided by the Pb-doping. This level is located at 0.37 eV from the conduction band edge (EC) and shows an apparent capture cross-section of 7x10-15cm2. In addition, another irradiation induced deep level located at EC - 0.32 eV has been studied in more details.


Author(s):  
М.М. Соболев ◽  
Ф.Ю. Солдатенков

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.


1999 ◽  
Vol 572 ◽  
Author(s):  
T. Henkel ◽  
Y. Tanaka ◽  
N. Kobayashi ◽  
H. Tanoue ◽  
M. Gong ◽  
...  

ABSTRACTStructural and electrical properties of beryllium implanted silicon carbide have been investigated by secondary ion mass spectrometry, Rutherford backscattering as well as deep level transient spectroscopy, resistivity and Hall measurements. Strong redistributions of the beryllium profiles have been found after a short post-implantation anneal cycle at temperatures between 1500 °C and 1700 °C. In particular, diffusion towards the surface has been observed which caused severe depletion of beryllium in the surface region. The crystalline state of the implanted material is well recovered already after annealing at 1450 °C. However, four deep levels induced by the implantation process have been detected by deep level transient spectroscopy.


2014 ◽  
Vol 104 (19) ◽  
pp. 192106 ◽  
Author(s):  
Sandip Das ◽  
Sandeep K. Chaudhuri ◽  
Raghu N. Bhattacharya ◽  
Krishna C. Mandal

2021 ◽  
Vol 21 (3) ◽  
pp. 1904-1908
Author(s):  
Woo-Young Son ◽  
Jeong Hyun Moon ◽  
Wook Bahng ◽  
Sang-Mo Koo

We investigated the effect of a sacrificial AlN layer on the deep energy level states of 4H-SiC surface. The samples with and without AlN layer have been annealed at 1300 °C for 30 minutes duration using a tube furnace. After annealing the samples, the changes of the carbon vacancy (VC) related Z1/2 defect characteristics were analyzed by deep level transient spectroscopy. The trap energy associated with double negative acceptor (VC(2-/0)) appears at ˜0.7 eV and was reduced from ˜0.687 to ˜0.582 eV in the sacrificial AlN layer samples. In addition, the capture cross section was significantly improved from ˜2.1×10-14 to ˜3.8×10−16 cm−2 and the trap concentration was reduced by approximately 40 times.


2003 ◽  
Vol 763 ◽  
Author(s):  
Richard S. Crandall

AbstractThis paper presents data showing a Meyer-Neldel rule (MNR) in InGaAsN alloys. It is shown that without this knowledge, significant errors will be made using Deep-Level Transient-Spectroscopy (DLTS) emission data to determine capture cross sections. By correctly accounting for the MNR in analyzing the DLTS data the correct value of the cross section is obtained.


2017 ◽  
Vol 897 ◽  
pp. 279-282 ◽  
Author(s):  
Hussein M. Ayedh ◽  
Maurizio Puzzanghera ◽  
Bengt Gunnar Svensson ◽  
Roberta Nipoti

A vertical 4H-SiC p-i-n diode with 2×1020cm-3 Al+ implanted emitter and 1950°C/5min post implantation annealing has been characterized by deep level transient spectroscopy (DLTS). Majority (electron) and minority (hole) carrier traps have been found. Electron traps with a homogeneous depth profile, are positioned at 0.16, 0.67 and 1.5 eV below the minimum edge of the conduction band, and have 3×10-15, 1.7×1014, and 1.8×10-14 cm2 capture cross section, respectively. A hole trap decreasing in intensity with decreasing pulse voltage occurs at 0.35 eV above the maximum edge of the valence band with 1×1013 cm2 apparent capture cross section. The highest density is observed for the refractory 0.67 eV electron trap that is due to the double negative acceptor states of the carbon vacancy.


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