A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Epitaxy

2000 ◽  
Vol 639 ◽  
Author(s):  
A.J. Ptak ◽  
T.H. Myers ◽  
Lijun Wang ◽  
N.C. Giles ◽  
M. Moldovan ◽  
...  
Keyword(s):  
Atomic Hydrogen ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Rf Plasma ◽  
Dopant Incorporation ◽  
Optical Activation ◽  
P Type ◽  
Kinetics Of ◽  
Secondary Ion

ABSTRACTStep-doped structures of both magnesium and beryllium were grown in GaN and analyzed using secondary ion mass spectrometry. Dopant incorporation was studied as a function of substrate temperature and dopant flux for Ga-polarity and N-polarity GaN. Incorporation is different for each polarity, with Mg incorporating by up to a factor of 20 times more (30 times more with atomic hydrogen) on the Ga-face, while Be incorporates more readily on the N-face. The effect of atomic hydrogen on the incorporation kinetics of both Mg and Be is also discussed. Mg and Be both undergo surface segregation during growth. Photoluminescence measurements suggest that Be is a p-type dopant with an optical activation energy of approximately 100 meV.

Near-Surface Aggregation of Sn In Heavily Sn-Doped GaAs Films Grown By Molecular Beam Epitaxy

1985 ◽  
Vol 43 ◽  
pp. 368-369
Author(s):  
S. H. Chen
Keyword(s):  
Molecular Beam Epitaxy ◽  
Cross Section ◽  
Electron Spectroscopy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Specimen Preparation ◽  
Near Surface ◽  
Gaas Films ◽  
Secondary Ion

Sn has been used extensively as an n-type dopant in GaAs grown by molecular-beam epitaxy (MBE). The surface accumulation of Sn during the growth of Sn-doped GaAs has been observed by several investigators. It is still not clear whether the accumulation of Sn is a kinetically hindered process, as proposed first by Wood and Joyce, or surface segregation due to thermodynamic factors. The proposed donor-incorporation mechanisms were based on experimental results from such techniques as secondary ion mass spectrometry, Auger electron spectroscopy, and C-V measurements. In the present study, electron microscopy was used in combination with cross-section specimen preparation. The information on the morphology and microstructure of the surface accumulation can be obtained in a fine scale and may confirm several suggestions from indirect experimental evidence in the previous studies.

The Formation of Abrupt N+ Doping Profiles Using Atomic Hydrogen and Sb During Si MBE

1998 ◽  
Vol 533 ◽  
Author(s):  
P.E. Thompson ◽  
C. Silvestre ◽  
M. Twigg ◽  
G. Jernigan ◽  
D.S. Simons
Keyword(s):  
Atomic Hydrogen ◽  
Molecular Beam ◽  
Secondary Ion Mass Spectrometry ◽  
Molecular Beam Epitaxy Growth ◽  
Atomic Concentration ◽  
Hall Measurements ◽  
N Doping ◽  
Sb Doping ◽  
Doping Profiles ◽  
Secondary Ion

AbstractPreviously, atomic hydrogen has been shown to be effective in reducing the segregation of Sb on Si(100) during solid source molecular beam epitaxy growth. In this work we have investigated the electrical activation of the Sb. Using Hall measurements, spreading resistance profilometry, and secondary ion mass spectrometry, we have demonstrated that the co-deposition of atomic hydrogen during Sb doping of Si at 500°C produced well-defined doping spikes. Comparing the sheet carrier concentration obtained by Hall measurements to the Sb atomic concentration obtained by SIMS, the overall activation of the Sb was greater than 50%.

Plasma-Assisted MBE of GaN and AlGaN on 6H SiC(0001)

1995 ◽  
Vol 395 ◽  
Author(s):  
S. Sinharoy ◽  
A. K. Agarwal ◽  
G. Augustine ◽  
L. B. Rowland ◽  
R. L. Messham ◽  
...  
Keyword(s):  
Room Temperature ◽  
Molecular Beam ◽  
Reverse Bias ◽  
Secondary Ion Mass Spectrometry ◽  
Operating Temperature ◽  
Leakage Currents ◽  
Activation Rate ◽  
P Type ◽  
A1n Buffer Layer ◽  
Secondary Ion

ABSTRACTThe growth of undoped and doped GaN and AlGaN films on off-axis 6H SiC substrates was investigated using plasma-assisted molecular beam epitaxy (MBE). Smooth and crack-free GaN and AlGaN films were obtained; the best results occurred at the highest growth temperature studied (800°C) and with a 40 to 50 nm A1N buffer layer grown at the same temperature. Carrier concentrations of up to n = 4 × 1020 cm−3 were accomplished with silicon, with a 40 to 50% activation rate as determined by secondary ion mass spectrometry (SIMS). Unintentionally doped AlxGa,.xN (x≈0.1) was n-type with a carrier concentration of 7 × 1018 cm−3. N-type AlGaN (x≈0.1)/p-type 6H SiC (0001) heterostructures showed excellent junction characteristics with leakage currents of less than 0.1 nA at 5 V reverse bias at room temperature and 0.5 nA at 200°C operating temperature.

Determination of the Distribution of Ion Implantation Boron in Silicon

2000 ◽  
Vol 650 ◽  
Author(s):  
Te-Sheng Wang ◽  
A.G. Cullis ◽  
E.J.H. Collart ◽  
A.J. Murrell ◽  
M.A. Foad
Keyword(s):  
Electron Microscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Low Energy ◽  
Concentration Profiles ◽  
Impurity Profile ◽  
Transmission Electron ◽  
Device Applications ◽  
P Type ◽  
Secondary Ion

ABSTRACTBoron is the most important p-type dopant in Si and it is essential that, especially for low energy implantation, both as-implanted B distributions and those produced by annealing should be characterized in very great detail to obtain the required process control for advanced device applications. While secondary ion mass spectrometry (SIMS) is ordinarily employed for this purpose, in the present studies implant concentration profiles have been determined by direct B imaging with approximately nanometer depth and lateral resolution using energy-filtered imaging in the transmission electron microscopy. The as-implanted B impurity profile is correlated with theoretical expectations: differences with respect to the results of SIMS measurements are discussed. Changes in the B distribution and clustering that occur after annealing of the implanted layers are also described.

Investigation of Aluminum Incorporation in 4H-SiC Epitaxial Layers

2014 ◽  
Vol 806 ◽  
pp. 45-50 ◽  
Author(s):  
Roxana Arvinte ◽  
Marcin Zielinski ◽  
Thierry Chassagne ◽  
Marc Portail ◽  
Adrien Michon ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Present Contribution ◽  
Growth Pressure ◽  
Temperature Growth ◽  
Dopant Incorporation ◽  
Capacitance Voltage ◽  
Secondary Ion

In the present contribution, the trends in voluntary incorporation of aluminum in 4H-SiC homoepitaxial films are investigated. The films were grown on Si-and C-face 4H-SiC 8°off substrates by chemical vapor deposition (CVD) in a horizontal, hot wall CVD reactor. Secondary Ion Mass Spectrometry (SIMS) and capacitance-voltage (C-V) measurements were used to determine the Al incorporation in the samples. The influence of Trimethylaluminum (TMA) flow rate, growth temperature, growth pressure and C/Si ratio on the dopant incorporation was studied.

Oxygen Gettering and Thermal Donor Formation at Post-Implantation Annealing of Hydrogen Implanted Czochralski Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
A. G. Ulyashin ◽  
Yu. A. Bumay ◽  
W. R. Fahrner ◽  
A. I. Ivanovo ◽  
R. Job ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Hydrogen Ions ◽  
Enhanced Diffusion ◽  
Thermal Donor ◽  
Float Zone ◽  
Donor Formation ◽  
Effect Of Oxygen ◽  
P Type ◽  
Secondary Ion ◽  
Post Implantation

ABSTRACTThe effect of oxygen gettering by buried defect layers at post-implantation annealing of hydrogen implanted Czochralski (Cz) grown silicon has been investigated. Hydrogen ions were implanted with an energy of 180 keV and doses of 2.7.1016cm−2 into p-type Cz and for comparison into p-type float zone (Fz) Si. The samples were annealed at temperatures between 400 °C and 1200 °C in a forming gas ambient and examined by secondary ion mass spectrometry (SIMS) in order to measure the hydrogen and oxygen concentration profiles. Spreading resistance probe (SRP) measurements were used to obtain depth resolved profiles of the resistivity. The observed changes of the resistivity after post-implantation annealing of hydrogen implanted Cz and Fz Si can be explained by hydrogen enhanced thermal donor formation processes (oxygen or hydrogen related) and charges at the SiOx precipitates. The effective oxygen gettering in hydrogen implanted Cz silicon is attributed to hydrogen enhanced diffusion of oxygen to buried defect layers.

Diffusion of Boron in Silicon and Silicon-Germanium in the Presence of Carbon

2005 ◽  
Vol 237-240 ◽  
pp. 998-1003
Author(s):  
Mudith S.A. Karunaratne ◽  
Janet M. Bonar ◽  
Jing Zhang ◽  
Peter Ashburn ◽  
Arthur F.W. Willoughby
Keyword(s):  
Mass Spectrometry ◽  
Diffusion Coefficients ◽  
Silicon Germanium ◽  
Molecular Beam ◽  
Secondary Ion Mass Spectrometry ◽  
Concentration Profiles ◽  
Boron Diffusion ◽  
Coated Surfaces ◽  
Secondary Ion ◽  
Strained Sige

Boron diffusion in Si and strained SiGe with and without C was studied. Using gassource molecular beam epitaxy (MBE), B containing epitaxial layers of: (i) Si, (ii) Si containing 0.1% C, (iii) SiGe with 11% Ge and (iv) SiGe with 11% Ge and with a 0.1% C, were grown on substrates. These samples were then rapid thermal annealed (RTA) at 940, 1000 and 1050°C in an O2 ambient. Self-interstitial-, vacancy- and non-injection conditions were achieved by annealing bare, Si3N4- and Si3N4+SiO2-coated surfaces, respectively. Concentration profiles of B, Ge and C were obtained using Secondary-Ion Mass Spectrometry (SIMS). Diffusion coefficients of B in each type of matrix were extracted by computer simulation. We find that B diffusivity is reduced by both Ge and C. The suppression due to C is much larger. In all materials, a substantial enhancement of B diffusion was observed due to self-interstitial injection compared to non-injection conditions. These results indicate that B diffusion in all four types of layers is mediated primarily by interstitialcy type defects.

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