The calibration of the strength of the localized vibrational modes of silicon impurities in epitaxial GaAs revealed by infrared absorption and Raman scattering

1989 ◽  
Vol 66 (6) ◽  
pp. 2589-2596 ◽  
Author(s):  
R. Murray ◽  
R. C. Newman ◽  
M. J. L. Sangster ◽  
R. B. Beall ◽  
J. J. Harris ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Infrared Absorption ◽  
Vibrational Modes ◽  
Epitaxial Gaas ◽  
Localized Vibrational Modes

Determination of the Bonding Configurations of Carbon Acceptors in InxGa1−xAs and AlxGa1−xAs

1995 ◽  
Vol 379 ◽  
Author(s):  
R. E. Pritchard ◽  
R.C. Newman ◽  
J. Wagner ◽  
M. Maier ◽  
A. Mazuelas ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Nearest Neighbors ◽  
Ir Absorption ◽  
Vibrational Modes ◽  
High Solubility ◽  
Compositional Range ◽  
Local Environments ◽  
Localized Vibrational Modes

ABSTRACTThe local environments of CAs acceptors in InxGa1−xAs and AlxGa1−xAs have been determined from the localized vibrational modes (LVMs) of both isolated CAs impurities and H-CAs pairs using infrared (IR) absorption and Raman scattering techniques. In as-grown layers of InxGa1−xAs (x<0.1), a single LVM due to isolated CAs acceptors was observed. The introduction of hydrogen led to the formation of H-CAs pairs and a single A1−-mode (stretch) and a single A1+-mode (XH) were observed for the InxGa1−xAs layers. All the LVMs were identified with carbon in CAsGa4 cluster configurations implying that less than 5 % of the detectable carbon atoms were present in clusters incorporating one or more CAs-In bonds. For AlxGa1−xAs, five stretch modes and five X-modes of the H-CAs pairs were observed for 0<x<1 and each mode was assigned to configurations for which the originally unpaired CAs had 0,1,2,3 or 4 Al nearest neighbors. These results show that carbon does not appear to form bonds with In atoms for the InxGa1−xAs samples investigated and this can explain the difficulty found in incorporating CAs acceptors in InxGa1−xAs with x>0.1 for some growth techniques. CAs acceptors can form strong bonds with both Al and Ga atoms, however, leading to a high solubility of carbon in AlxGa1-xAs over the full compositional range.

Silicon Delta Doping in GaAs: An Ongoing Enigma

1995 ◽  
Vol 378 ◽  
Author(s):  
R. C. Newman ◽  
M. J. Ashwin ◽  
J. Wagner ◽  
M. R. Fahy ◽  
L. Hart ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Surface Diffusion ◽  
Long Range ◽  
Electron Trap ◽  
Ir Absorption ◽  
Vibrational Modes ◽  
Thermally Activated ◽  
Delta Doping ◽  
Antisite Defects ◽  
Localized Vibrational Modes

AbstractInfrared (IR) absorption and Raman scattering are reported from the localized vibrational modes (LVM) of Al and Si δ-layer superlattices in MBE (100) GaAs grown at 400°C as a function of the total areal concentrations, [A1]A and [Si]A respectively. The Al superlattices show the expected behavior on passing from sub-monolayer (ML) to thicker layers (thin AlAs) since the impurities still occupy only Ga-sites. The behavior is very different from that found for Si δ-layers. In addition to SiGa reported previously, we now show that SiAs, SiGa-SiAs pairs and the electron trap Si-X are also present in Si δ-layers and superlattices for 0.05 ≤ [Si]A≤ 0.5 ML. The conductivity of these structures and the concentrations of substitutional Si in GaAs at all sites fall to zero for [Si]A> 0.5 ML but a Raman feature at 470–490 cm−1, attributed to the vibrations of covalent Si-Si bonds is then detected. This feature is not observed in structures containing very closely spaced dilute (0.01 ML) Si δ-planes. It is inferred that long-range Si diffusion does not occur in the bulk crystal, although there could be surface diffusion during Si deposition. The maximum measured carrier concentrations are always less than 2 × 1019 cm−3, the DX limit. The redistribution of Si amongst the various lattice sites is discussed in terms of SiGa DX-like displacements occurring during growth, followed by local thermally activated diffusion jumps. It is speculated that AsGa antisite defects and Ga-vacancies are produced by this process. The reason why the Si δ-layer is non-conducting remains unclear.

Raman Studies of Hydrogen Passivation in Silicon

1987 ◽  
Vol 104 ◽  
Author(s):  
M. Stutzmann ◽  
C. P. Herrero
Keyword(s):  
Raman Scattering ◽  
Optical Phonon ◽  
Vibrational Frequency ◽  
Crystalline Silicon ◽  
Structural Models ◽  
Uniaxial Stress ◽  
Vibrational Modes ◽  
Hydrogen Passivation ◽  
Raman Active Mode ◽  
Localized Vibrational Modes

ABSTRACTWe have studied the hydrogen passivation of boron acceptors in bulk crystalline silicon with Raman scattering. Upon hydro-genation, distinct changes in the optical phonon lineshape and the localized vibrational modes of boron are observed. The hy-drogen in the passivated region gives rise to a specific Raman-active mode, whose vibrational frequency depends strongly on temperature and uniaxial stress. Implications of these results on possible structural models are discussed.

Rapid Thermal Annealing of Oxygen-Vacancy Centers In O-Implanted Silicon

1987 ◽  
Vol 92 ◽  
Author(s):  
H. J. Stein
Keyword(s):  
Activation Energy ◽  
Oxygen Vacancy ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Infrared Absorption ◽  
Silicon On Insulator ◽  
Vibrational Modes ◽  
Annealing Stage ◽  
Localized Vibrational Modes

ABSTRACTInfrared absorption by localized vibrational modes has been used to investigate rapid thermal annealing (RTA) of oxygen-vacancy (O-V) defects in O-implanted Si. At least three processes are involved in the annealing of O-V defects. An activation energy of 1.0 ± 0.2 eV for a process leading to O-V formation is attributed to O-V diffusion. The final O-V annealing stage is attributed to oxygen clustering around O2-V centers. Processes observed here in RTA are expected to be operative during implantation at the temperatures (400 to 600°C) used for production of silicon-on-insulator structures.

Raman scattering from localized vibrational modes of boron impurities in silicon

1971 ◽  
Vol 9 (20) ◽  
pp. 1719-1721 ◽  
Author(s):  
W. Nazarewicz ◽  
M. Balkanski ◽  
J.F. Morhange ◽  
C. Sébenne
Keyword(s):  
Raman Scattering ◽  
Vibrational Modes ◽  
Localized Vibrational Modes
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