Band Bending at the Gold (Au)/Boron Carbide-Based Semiconductor Interface

2018 ◽  
Vol 232 (5-6) ◽  
pp. 893-905 ◽  
Author(s):  
Elena Echeverría ◽  
George Peterson ◽  
Bin Dong ◽  
Simeon Gilbert ◽  
Adeola Oyelade ◽  
...  
Keyword(s):  
Boron Carbide ◽  
Aromatic Compounds ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Photoemission Spectroscopy ◽  
Semiconductor Interface ◽  
Band Bending ◽  
X Ray ◽  
Barrier Formation ◽  
P Type

Abstract We have used X-ray photoemission spectroscopy to study the interaction of gold (Au) with novel boron carbide-based semiconductors grown by plasma-enhanced chemical vapor deposition (PECVD). Both n- and p-type films have been investigated and the PECVD boron carbides are compared to those containing aromatic compounds. In the case of the p-type semiconducting PECVD hydrogenated boron carbide samples, the binding energy of the B(1s) core level shows a shift to higher binding energies as the Au is deposited, an indication of band bending and possibly Schottky barrier formation. In the case of the n-type boron carbide semiconductors the interaction at the interface is more typical of an ohmic contact. Addition of the aromatic compounds increases the change in binding energies on both n-type and p-type PECVD boron carbide semiconductors, and the gold appears to diffuse into the PECVD boron carbides alloyed with aromatic moieties.

Photoemission Studies of the Ag/InP(110) Interface: Interfacial Reactions and Schottky Barrier Formation

1983 ◽  
Vol 25 ◽  
Author(s):  
W. G. Petro ◽  
T. Kendelewicz ◽  
I. A. Babalola ◽  
I. Lindau ◽  
W. E. Spicer
Keyword(s):  
Valence Band Maximum ◽  
Interfacial Reactions ◽  
Core Level ◽  
Photoemission Spectroscopy ◽  
Band Bending ◽  
X Ray ◽  
Barrier Formation ◽  
Deconvolution Technique ◽  
P Type ◽  
Measurable Change

ABSTRACTRoom-temperature interfacial reactions at the Ag/InP (110) interface have been studied using soft x-ray photoemission spectroscopy of the In 4d and P 2p core levels. For low Ag coverages (less than 1 monolayer (ML)) no measurable change in core level shapes is observed, and the shift in core level position is due solely to band bending. At high Ag coverages (up to 72 ML) we observe dissociated In metal, P atoms near the surface, and Ag clustering. Fermi level movement is deduced from these spectra using a deconvolution technique, and pinning positions of 0.40 ± 0.05 eV below the conduction-band minimum for n-type and 0.5 ± 0.l eV above the valence-band maximum for p-type are found. These positions are in close agreement with calculations of native defect levels.

Process-Dependent Electronic Structure at Metallized GaAs Contacts

1992 ◽  
Vol 260 ◽  
Author(s):  
L. J. Brillson ◽  
I. M. Vitomirov ◽  
A. Raisanen ◽  
S. Chang ◽  
R. E. Viturro ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Chemical Interaction ◽  
Deep Level ◽  
Multiple Roles ◽  
Atomic Scale ◽  
Photoemission Spectroscopy ◽  
Band Bending ◽  
Barrier Heights ◽  
Barrier Formation ◽  
Thermally Driven

ABSTRACTThe influence of metallization and processing on Schottky barrier formation provides the basis for one of several fruitful approaches for controlling junction electronic properties. Interface cathodo-and photoluminescence measurements reveal that electrically-active deep levels form on GaAs(100) surfaces and metal interfaces which depend on thermally-driven surface stoichiometry and reconstruction, chemical interaction, as well as surface misorientation and bulk crystal quality. These interface states are discrete and occur at multiple gap energies which can account for observed band bending. Characteristic trends in such deep level emission with interface processing provide guides for optimizing interface electronic behavior. Correspondingly, photoemission and internal photoemission spectroscopy measurements indicate self-consistent changes in barrier heights which may be heterogeneous and attributable to interface chemical reactions observed on a monolayer scale. These results highlight the multiple roles of atomic-scale structure in forming macroscopic electronic properties of compound semiconductor-metal junctions.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

Photoluminescence Intensity Enhancement of GaAs by Vapor-Deposited GaS: a Rational Approach to Surface Passivation

1992 ◽  
Vol 282 ◽  
Author(s):  
Phillip P. Jenkins ◽  
Aloysius F. Hepp ◽  
Michael B. Power ◽  
Andrew R. Macinnes ◽  
Andrew R. Barrontt
Keyword(s):  
Surface Passivation ◽  
Surface Recombination ◽  
Chemical Vapor ◽  
Surface Recombination Velocity ◽  
Rational Approach ◽  
Cubic Phase ◽  
Photoluminescence Intensity ◽  
Band Bending ◽  
X Ray ◽  
Order Of Magnitude

ABSTRACTA two order-of-magnitude enhancement of photoluminescence intensity relative to untreated GaAs has been observed for GaAs surfaces coated with chemical vapor-deposited GaS. The increase in photoluminescence intensity can be viewed as an effective reduction in surface recombination velocity and/or band bending. The gallium cluster [(t-Bu)GaS]4 was used as a single-source precursor for the deposition of GaS thin films. The cubane core of the structurally-characterized precursor is retained in the deposited film producing a cubic phase. Furthermore, a near-epitaxial growth is observed for the GaS passivating layer. Films were characterized by transmission electron microscopy, X-ray powder diffraction, and X-ray photoelectron and Rutherford backscattering spectroscopies.

The Growth of Si on SiC Complex Substrate by CVD

2012 ◽  
Vol 490-495 ◽  
pp. 3840-3844
Author(s):  
W. Cheng ◽  
P. Han ◽  
F. Yu ◽  
L. Yu ◽  
L.H. Cheng ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Crystalline Quality ◽  
X Ray Diffraction ◽  
Crystalline Orientation ◽  
X Ray ◽  
Measurement Results ◽  
Different Temperatures ◽  
P Type ◽  
Sic Film ◽  
Sic Films

In this work, the Si layer is deposited on the SiC complex substrate which is composed of Si(111) substrate and 3C-SiC film grown on it. These Si and 3C–SiC films grown under different temperatures in a chemical vapor deposition system are analyzed. The crystalline orientation, the crystalline quality and the conduction type of the films are measured by X-ray diffraction, Raman scattering ,Scanning electron microscope, and 1150 °C is found the optimized temperature for the epitaxial growth of SiC film grown on the carbonized layer. Measurement results also show that the epitaxial layer is n-type 3C-SiC which has the same crystalline orientation with the Si (111) substrate. Si film grown on the SiC complex substrate under the temperature of 690 °C has the best crystalline quality. This film is composed of p-type monocrystal Si and has the same crystalline orientation with the substrate.

Structural Defects and Critical Electric Field in 3C-SiC

2006 ◽  
Vol 527-529 ◽  
pp. 431-434 ◽  
Author(s):  
Michael A. Capano ◽  
A.R. Smith ◽  
Byeung C. Kim ◽  
E.P. Kvam ◽  
S. Tsoi ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Electric Field ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Chemical Vapor ◽  
Structural Defects ◽  
X Ray ◽  
Transmission Electron ◽  
Current Voltage ◽  
P Type

3C-SiC p-type epilayers were grown to thicknesses of 1.5, 3, 6 and 10 μm on 2.5° off-axis Si(001) substrates by chemical vapor deposition (CVD). Silane and propane were used as precursors. Structural analysis of epilayers was performed using transmission electron microscopy (TEM), high-resolution x-ray diffractometry (HRXRD), and Raman spectroscopy. TEM showed defect densities (stacking faults, twins and dislocations) decreasing with increasing distance from the SiC/Si interface as the lattice mismatch stress is relaxed. This observation was corroborated by a monotonic decrease in HRXRD peak width (FWHM) from 780 arcsecs (1.5 μm thick epilayer) to 350 arcsecs (10 μm thick epilayer). Significant further reduction in x-ray FWHM is possible because the minimum FWHM detected is greater than the theoretical FWHM for SiC (about 12 arcsecs). Raman spectroscopy also indicates that the residual biaxial in-plane strain decreases with increasing epilayer thickness initially, but becomes essentially constant between 6 and 10 μm. Structural defect density shows the most significant reduction in the first 2 μm of growth. Phosphorus implantation was used to generate n+/p junctions for the measurement of the critical electric field in 3C-SiC. Based on current-voltage analyses, the critical electric field in p-type 3C-SiC with a doping of 2x1017 cm-3 is 1.3x106 V/cm.

Barrier Height Control and X-Ray Diffraction Study of Metal on Si1−Gex/Si Grown by Very Low Pressure CVD

1995 ◽  
Vol 402 ◽  
Author(s):  
Z. Q. Shiâ ◽  
L. He ◽  
Y. Zheng
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Schottky Diodes ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Control Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Height Control ◽  
Barrier Formation

AbstractThe potential application of epitaxial Si1−xGex, on Si in electronic and optoelectronic devices has led to an increased study of metal - Si1−xGex interaction and barrier height control technique. In this paper, we report the epitaxial growth of Si1−xGex on Si and the Schottky barrier formation processing. The Si1−xGex (x=0.17 and 0.20) layers were grown by rapid radiant heating, very low pressure chemical vapor deposition (VLPCVD). The crystal structure and epitaxial nature of the Si1−xGex, layers were studied by X-Ray diffraction. The value of full width at half maximum (FWHM) was found to be 0.34° for the as grown Si1−xGex (400) peak. The metal-Si1−xGex/Si Schottky diodes were formed by depositing Pd on Si1−xGex/Si at room temperature (RT=300K) and low temperature (LT=77K). The Schottky barrier heights and current transport mechanisms were determined by current-voltage-temperature (I-V-T) measurements. The interface property of Pd/ Si1−xGex/Si were studied as a function of metal deposition and post annealing temperatures.

X-Ray Photoemission Spectromicroscopy Of Gan And AIGan

1998 ◽  
Vol 512 ◽  
Author(s):  
G. F. Lorusso ◽  
H. Solak ◽  
F. Cerrina ◽  
J. H. Underwood ◽  
P. J. Batson ◽  
...  
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Sample Surface ◽  
Photoemission Spectroscopy ◽  
Chemical Inhomogeneity ◽  
X Ray ◽  
Spatially Resolved ◽  
First Time

ABSTRACTWe investigate here for the first time GaN and AIGaN films by using x-ray photoemission spectromicroscopy. As compared to conventional x-ray photoemission spectroscopy (XPS), spectromicroscopy can provide spatially resolved information on the chemical composition of the sample surface. The experimental results where obtained by using MAXIMUM, a scanning photoemission microscope installed on 12.0 undulator beamline at the Advanced Light Source (ALS), Berkelely, allowing for a spatial resolution of 100 nm. We investigate here GaN and AlGaN thin films grown on sapphire substrate by metalorganic chemical vapor deposition (MOCVD). The results clearly indicate the great potential of spectromicroscopy in investigating chemical inhomogeneity, inpurities and localization in GaN and AlGaN thin films.

PHOTOEMISSION STUDY OF THE GADOLINIUM/GaAs(100) INTERFACE WITH SYNCHROTRON RADIATION

1997 ◽  
Vol 04 (01) ◽  
pp. 25-31 ◽  
Author(s):  
SHIHONG XU ◽  
FAPEI ZHANG ◽  
ERDONG LU ◽  
XIAOJIANG YU ◽  
FAQIANG XU ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Epitaxial Growth ◽  
Room Temperature ◽  
Interface Structure ◽  
Binding Energies ◽  
Photoemission Spectroscopy ◽  
Interface Formation ◽  
X Ray ◽  
Solution Density ◽  
Photoemission Study

Soft-X-ray photoemission spectroscopy was used to characterize the Gd/GaAs(100)-interface formation at room temperature. At low Gd coverage (<1 Å), the interface is near-abrupt, because no evidence of reaction is observed. With increasing Gd coverage, photoemission signals from chemically reacted product at the interface are observed, causing some intermixing between the overlayer and the substrate. For As atoms, they remain near the interface and have little diffusion. Ga atoms, however, are not kept near the interface, and they can diffuse into the Gd overlayer and segregate onto the surface instead. From the observed variations with metal coverage of binding energies and relative intensities of photoemission signals from the reacted layer, a profile of the interface structure is proposed, and some parameters (decaying length, segregation density and solution density, etc.) have been obtained. The results show that the deposition of Gd onto the GaAs (100) surface induces limited substrate disruption except for some diffusion and segregation of Ga atoms into the metal overlayer. This paper demonstrates that the disruption and epitaxial growth are not mutually exclusive in the Gd / GaAs (100) system.

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