Characterization of Defects Created in Silicon Due to Etching in Low-Pressure Plasmas Containing Fluorine and Oxygen

1995 ◽  
Vol 396 ◽  
Author(s):  
I. A. Buyanova ◽  
A. Henry ◽  
B. Monemar ◽  
J. L. Lindström ◽  
A. Lamprecht ◽  
...  
Keyword(s):  
Deep Level ◽  
Surface Region ◽  
Energy Shift ◽  
Low Pressure ◽  
Extended Defects ◽  
Near Surface ◽  
Defect Complexes ◽  
Radiation Induced ◽  
Dlts Spectra

AbstractDefect characterization in n-type silicon after the reactive ion etching (RIE) in low-pressure plasmas containing fluorine and oxygen is performed by using photoluminescence (PL) and deep level transient spectroscopies (DLTS). It is shown that RIE treatment results in the formation of (i) luminescence centers giving rise to the C- and G- excitonic lines and broad emission bands related to radiation-induced defect complexes and extended defects and (ii) several electron traps located at 0.16 eV, 0.26 eV, 0.43 eV and 0.58 eV below the conduction band. The addition of oxygen to the SF6 and CF4 plasma is shown to cause nonuniform stress in the near surface region. This stress is responsible for the experimentally observed splitting of the C- and G-excitonic lines, a low energy shift of the phosphorous bound exciton lines, as well as the splitting of the DLTS spectra. It is shown that the stress field is highly inhomogeneous across the wafer, and is rather related to the RIE-induced extended defects than caused by the reaction layer formed on the Si surface.

BIC Formation and Boron Diffusion in Relaxed Si0.8Ge0.2

2004 ◽  
Vol 810 ◽  
Author(s):  
R. T. Crosby ◽  
L. Radic ◽  
K. S. Jones ◽  
M. E. Law ◽  
P.E. Thompson ◽  
...  
Keyword(s):  
Surface Region ◽  
Extended Defects ◽  
Defect Structures ◽  
Boron Diffusion ◽  
Plan View ◽  
Near Surface ◽  
Transmission Electron ◽  
Secondary Ion ◽  
Ion Implanted

ABSTRACTThe relationships between Boron Interstitial Cluster (BIC) evolution and boron diffusion in relaxed Si0.8Ge0.2 have been investigated. Structures were grown by Molecular Beam Epitaxy (MBE) with surface boron wells of variant composition extending 0.25 [.proportional]m into the substrate, as well as boron marker layers positioned 0.50 [.proportional]m below the surface. The boron well concentrations are as follows: 0, 7.5×1018, 1.5×1019, and 5.0×1019 atoms/cm3. The boron marker layers are approximately 3 nm wide and have a peak concentration of 5×1018 atoms/cm3. Samples were ion implanted with 60 keV Si+ at a dose of 1×1014 atoms/cm2 and subsequently annealed at 675°C and 750°C for various times. Plan-view Transmission Electron Microscopy (PTEM) was used to monitor the agglomeration of injected silicon interstitials and the evolution of extended defects in the near surface region. Secondary Ion Mass Spectroscopy (SIMS) concentration profiles facilitated the characterization of boron diffusion behaviors during annealing. Interstitial supersaturation conditions and the resultant defect structures of ion implanted relaxed Si0.8Ge0.2 in both the presence and absence of boron have been characterized.

Characterization of the near-surface region in ion-exchanged glass waveguides

2001 ◽  
Author(s):  
Flavio Horowitz ◽  
Marcelo B. Pereira ◽  
M. Behar ◽  
Luiz C. Barbosa ◽  
Stefano Pelli ◽  
...  
Keyword(s):  
Surface Region ◽  
Near Surface ◽  
Glass Waveguides

Optical Investigation of Electronic Properties in Bulk and Surface Region of Sublimation-Grown 3C-SiC Crystals

2009 ◽  
Vol 615-617 ◽  
pp. 303-306 ◽  
Author(s):  
Georgios Manolis ◽  
Kęstutis Jarašiūnas ◽  
Irina G. Galben-Sandulache ◽  
Didier Chaussende
Keyword(s):  
Carrier Density ◽  
Defect Density ◽  
Surface Region ◽  
Carrier Dynamics ◽  
Optical Investigation ◽  
Extended Defects ◽  
A Value ◽  
Continuous Feed ◽  
The Given

We applied a picosecond dynamic grating technique for studies of nonequilibrium carrier dynamics in a 0.8 mm thick bulk 3C-SiC crystal grown by the continuous feed physical vapor transport (CF-PVT) on 6H-SiC (0001) substrate. Investigation of carrier dynamics at surface or bulk excitation conditions was performed for excess carrier density in range from ~ 1017 cm-3 to ~ 1020 cm3 using for excitation weakly or strongly absorbed illumination. In DPBs free domains, the bipolar diffusion coefficient and carrier lifetime value at 300K were found gradually increasing with carrier density. The bipolar mobility vs. temperature dependence, μ. ~ T -k, provided a value k = 1.2 - 2 in range T < 100 K, thus indicating a negligible scattering by point and extended defects. These data indicated strong contribution of the carrier-density dependent but not defect-density governed scattering mechanisms, thus indicating high quality of the CF-PVT grown bulk cubic SiC. These studies were found in good correlation with the structural and photoluminescence characterization of the given crystal.

Characterisation of the Subthreshold Damage in MeV Ion Implanted p Si

1998 ◽  
Vol 510 ◽  
Author(s):  
Shabih Fatima ◽  
Jennifer Wong-Leung ◽  
John Fitz Gerald ◽  
C. Jagadish
Keyword(s):  
Point Defects ◽  
Deep Level Transient Spectroscopy ◽  
Damage Evolution ◽  
Peak Concentration ◽  
Deep Level ◽  
Extended Defects ◽  
Transmission Electron ◽  
Transient Spectroscopy ◽  
P Type ◽  
Dlts Spectra

AbstractSubthreshold damage in p-type Si implanted and annealed at elevated temperature is characterized using deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). P-type Si is implanted with Si, Ge and Sn with energies in the range of 4 to 8.5 MeV, doses from 7 × 1012to 1×1014cm−2and all annealed at 800°C for 15 min. For each implanted specie, DLTS spectra show a transition dose called threshold dose above which point defects transform in to extended defects. DLTS measurements have shown for the doses below threshold, a sharp peak, corresponding to the signature of point defects and for doses above threshold a broad peak indicating the presence of extended defects. This is found to be consistent with TEM analyses where no defects are seen for the doses below threshold and the presence of extended defects for the doses above threshold. This suggests a defect transformation regime where point defects present below threshold are acting like nucleating sites for the extended defects. Also the mass dependence on the damage evolution has been observed, where rod-like defects are observed in the case of Si and (rod-like defects and loops) for Ge and Sn despite the fact that peak concentration of vacancies for Ge and Sn are normalized to the peak number of vacancies for Si.

The Characterization of WC-Co Based Materials Boronized within Molten Salt Bath

2008 ◽  
Vol 144 ◽  
pp. 261-266 ◽  
Author(s):  
Sakıp Köksal
Keyword(s):  
Molten Salt ◽  
Physical Vapor Deposition ◽  
Surface Region ◽  
Salt Bath ◽  
Functionally Graded ◽  
Near Surface ◽  
Diffusion Treatment ◽  
Physical Deposition ◽  
Molten Salt Bath

Coated WC-Co based cutting tool materials are widely used in machining applications. However some of the coating techniques, such as physical vapor deposition (PVD), involve only the physical deposition of coating layers which are prone to bulk delamination in some applications. Therefore functionally graded microstructure through diffusion is an efficient and widely used methods to improve the performance of coated WC-Co tools. In this work ISO P25, WC-Co based inserts were subjected to a thermochemical diffusion treatment by boronizing in a molten salt bath. The process was performed at 900, 1000, and 1100 °C for 1, 2 and 4 h. SEM, X-ray, EDS and microhardness analysis were performed on the samples. It was found that boron containing hard phases of W 2 B 5 , CoB, W 2 CoB 2 and WCoB were formed within the boronized region, occupying the grain boundary areas. An average microhardness value of 3600 HK 0.01 was measured in the near surface region which is substantially higher than the value of 1418 HK 0.01 representing the inner sections of the material.

Role Of Deep Level Trapping On Surface Photovoltage Of semiinsulating GaAs

1996 ◽  
Vol 426 ◽  
Author(s):  
Qiang Liu ◽  
Harry E. Ruda ◽  
Ivoil P. Koutzarov ◽  
Lech Jedral ◽  
Genmao Chen ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Deep Level ◽  
Surface Region ◽  
Interface State ◽  
Thermal Recovery ◽  
Surface Photovoltage ◽  
Effective Electron ◽  
Near Surface ◽  
Dual Beam ◽  
Bias Pulse

AbstractDual beam (bias and probe) transient Surface Photovoltage (SPV) measurements were made on undoped Semi-Insulating (SI) GaAs over an extended temperature range. Above 270 K, SPV recovery transients following a bias pulse were shown to reflect near surface conductivity changes; these are in turn controlled by surface/interface state thermal emission. Owing to the absence of a strong surface electric field in this material, the emitted carriers are not immediately removed from the near surface region. The recapturing of the emitted carriers is shown to be responsible for non-exponential conductivity and reciprocal-SPV transients. This behavior is considered to be characteristic of relaxation-type semiconductors with near-surface ungated structures. Below 150 K, the photoinduced transition of EL2 from its ground to metastable state EL2& was shown to change the effective electron and hole mobilities and augment the SPV signals immediately following the bias pulse. Thermally induced EL2& recovery above 120 K decreases the SPV signal from its maximum. This decay transient was analyzed and the decay rate fitted to a single exponential. An activation energy of 0.32 eV and a pre-exponential constant of 1. 9× 1012 s−1 were obtained, and attributed to the thermal recovery rate for EL2&.

Characterization of Material Phases on the Surface and in the Near-Surface Region of Scandate Cathodes

2020 ◽  
Author(s):  
Xiaotao Liu ◽  
Matthew J. Beck ◽  
T. John Balk ◽  
Bernard K. Vancil
Keyword(s):  
Surface Region ◽  
Near Surface

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
Keyword(s):  
Cross Section ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Surface Region ◽  
Conduction Band Edge ◽  
Defect Structures ◽  
Near Surface ◽  
Defect Levels ◽  
Transient Spectroscopy ◽  
Different Doses

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.

Synthesis of the Dilute Magnetic Semiconductor CdMnTe by Ion Implantation of Mn into CdTe

1986 ◽  
Vol 89 ◽  
Author(s):  
G. H. Braunstein ◽  
D. Heiman ◽  
S. P. Withrow ◽  
G. Dresselhaus
Keyword(s):  
Ion Implantation ◽  
Dilute Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Energy Shift ◽  
Complete Recovery ◽  
Characteristic Energy ◽  
Lattice Order ◽  
Near Surface ◽  
Radiation Induced ◽  
Ion Implanted

AbstractThe dilute magnetic semiconductor CdMnTe has been synthesized by ion implantation of Mn into CdTe. Samples of CdTe have been implanted with Mn ions of 60 keV energy to fluences in the range 1 × 1013 cm−2 to 2×1016 cm−2 and subsequently annealed, using rapid thermal annealing, for 10–15 sec at temperatures 300 ≤ TA ≤ 730°C. The successful formation of a near surface layer of CdMnTe is demonstrated by studies of the structural, electronic and magnetic properties of the ion implanted and annealed sampies; Rutherford backscattering-channeling analysis of the radiation-induced damage indicates complete recovery of lattice order after annealing at 700°C. Photoluminescence measurements, performed at 2K, reveal an increase in the energy band gap of the ion implanted alloy with respect to CdTe. Application of magnetic fields, up to 8T, produce both the characteristic energy shift of the excitonic recombination peak and polarization of the emitted radiation (in the Faraday configuration) previously observed in bulk–grown CdMnTe material.

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