scholarly journals Microscopic Views of Atomic and Molecular Oxygen Bonding with epi Ge(001)-2 × 1 Studied by High-Resolution Synchrotron Radiation Photoemission

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 554 ◽  
Author(s):  
Yi-Ting Cheng ◽  
Hsien-Wen Wan ◽  
Chiu-Ping Cheng ◽  
Jueinai Kwo ◽  
Minghwei Hong ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Atomic Oxygen ◽  
Subsurface Layer ◽  
Metal Oxide Semiconductor ◽  
Core Level ◽  
Oxide Semiconductor ◽  
Mos Devices ◽  
Level Shifts ◽  
A Charge ◽  
Synchrotron Radiation Photoemission

In this paper, we investigate the embryonic stage of oxidation of an epi Ge(001)-2 × 1 by atomic oxygen and molecular O2 via synchrotron radiation photoemission. The topmost buckled surface with the up- and down-dimer atoms, and the first subsurface layer behaves distinctly from the bulk by exhibiting surface core-level shifts in the Ge 3d core-level spectrum. The O2 molecules become dissociated upon reaching the epi Ge(001)-2 × 1 surface. One of the O atoms removes the up-dimer atom and the other bonds with the underneath Ge atom in the subsurface layer. Atomic oxygen preferentially adsorbed on the epi Ge(001)-2 ×1 in between the up-dimer atoms and the underneath subsurface atoms, without affecting the down-dimer atoms. The electronic environment of the O-affiliated Ge up-dimer atoms becomes similar to that of the down-dimer atoms. They both exhibit an enrichment in charge, where the subsurface of the Ge layer is maintained in a charge-deficient state. The dipole moment that was originally generated in the buckled reconstruction no longer exists, thereby resulting in a decrease in the ionization potential. The down-dimer Ge atoms and the back-bonded subsurface atoms remain inert to atomic O and molecular O2, which might account for the low reliability in the Ge-related metal-oxide-semiconductor (MOS) devices.

scholarly journals Microscopic Views of Atomic and Molecular Oxygen Bonding with epi Ge(001)-2×1 Studied by High-Resolution Synchrotron Radiation Photoemission

2019 ◽  
Author(s):  
Yi-Ting Cheng ◽  
Hsien-Wen Wan ◽  
Chiu-Ping Cheng ◽  
Jueinai Kwo ◽  
Minghwei Hong ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Atomic Oxygen ◽  
Subsurface Layer ◽  
Core Level ◽  
Oxide Semiconductor ◽  
Mos Devices ◽  
Level Shifts ◽  
Embryo Stage ◽  
A Charge ◽  
Synchrotron Radiation Photoemission

Embryo stage of oxidation of an epi Ge(001)-2×1 by atomic oxygen and molecular O2 is studied via synchrotron radiation photoemission. The topmost surface buckled with the up- and down-dimer atoms and the first subsurface layer behave distinctly from the bulk by exhibiting surface core-level shifts in the Ge 3d core-level spectrum. The O2 molecules become dissociated upon reaching the epi Ge(001)-2×1 surface. One of the O atom removes off the up-dimer atom, and the other bonds with the underneath Ge atom in the subsurface layer. Atomic oxygen adsorbed on the epi Ge(001)-2×1 preferentially in between the up-dimer atoms and the underneath subsurface atoms without affecting the down-dimer atoms. The electronic environment of the O-affiliated Ge up-dimer atoms becomes similar to that of the down-dimer atoms. Both exhibit an enrichment in charge, where the subsurface of the Ge layer is maintained in a charge-deficient state. The dipole moment originally generated in the buckled reconstruction no longer exists, thereby resulting in a decrease in the ionization potential. The down-dimer Ge atoms and the back-bonded subsurface atoms remain inert to atomic O and molecular O2, a possible cause of low reliability in Ge-related metal-oxide-semiconductor (MOS) devices.

Charge Trap Mechanism in Hybrid Nanostructured (YMnO3) Metal-Oxide-Semiconductor (MOS) Devices

2016 ◽  
Vol 42 ◽  
pp. 92-99
Author(s):  
J.H. Markna ◽  
Davit Dhruv ◽  
K.N. Rathod ◽  
Chirag Savaliya ◽  
T.M. Shiyani ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxide Layer ◽  
Debye Length ◽  
Anomalous Behavior ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Mos Capacitor ◽  
Charge Trap ◽  
Mos Devices ◽  
A Charge

Hybrid nanostructured Metal Oxide Semiconductor (MOS) capacitor was fabricated on silicon substrates (n-type) using chemical solution deposition with YMnO3 as an oxide layer. Electrical properties of MOS capacitor have been investigated with frequency dependence capacitance-voltage (C-V) characterization. The surface morphology of deposited layer was studied using the Atomic Force Microscopy (AFM). Hysteresis in the C-V loop and change in the values of Cminimum were described by a charge trap mechanism in the multiferroic oxide layer of MOS devices. While anomalous behavior in saturation capacitance in the inversion as well as in accumulation region and a shift in threshold voltage (VT) were explained in the vicinity of frequency depended Debye length (LDebye).

HIGH RESOLUTION SYNCHROTRON RADIATION PHOTOEMISSION SPECTROSCOPY

1997 ◽  
Vol 04 (02) ◽  
pp. 287-293 ◽  
Author(s):  
G. LE LAY
Keyword(s):  
Synchrotron Radiation ◽  
Surface Science ◽  
Core Level ◽  
Silicon Surfaces ◽  
Photoemission Spectroscopy ◽  
Level Shifts ◽  
Dimensional Electron Gas ◽  
Spectroscopy Studies ◽  
Synchrotron Radiation Photoemission ◽  
Very High

Photoemission spectroscopy studies with very-high-energetic resolution at third generation synchrotron radiation facilities open up new perspectives in surface science. To illustrate this, recent advances achieved from valence band studies will be described, i.e. investigation of the quantized electronic states of a two-dimensional electron gas at the InAs(110) surface. New insights gained from core level spectroscopy in the most promising soft X-ray regime will also be presented, i.e. evidence of new spectral features in Si 2p studies of low index silicon surfaces and identification of surface core level shifts in III–V semiconductors.

On Separating Oxide Charges and Interface Charges in 4H-SiC Metal-Oxide-Semiconductor Devices

2006 ◽  
Vol 527-529 ◽  
pp. 1007-1010 ◽  
Author(s):  
Daniel B. Habersat ◽  
Aivars J. Lelis ◽  
G. Lopez ◽  
J.M. McGarrity ◽  
F. Barry McLean
Keyword(s):  
Room Temperature ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Interface Traps ◽  
Mos Capacitors ◽  
Mos Devices ◽  
Interface Charges ◽  
Flatband Voltage ◽  
Oxide Traps ◽  
P Type

We have investigated the distribution of oxide traps and interface traps in 4H Silicon Carbide MOS devices. The density of interface traps, Dit, was characterized using standard C-V techniques on capacitors and charge pumping on MOSFETs. The number of oxide traps, NOT, was then calculated by measuring the flatband voltage VFB in p-type MOS capacitors. The amount that the measured flatband voltage shifts from ideal, minus the contributions due to the number of filled interface traps Nit, gives an estimate for the number of oxide charges present. We found Dit to be in the low 1011cm−2eV−1 range in midgap and approaching 1012 −1013cm−2eV−1 near the band edges. This corresponds to an Nit of roughly 2.5 ⋅1011cm−2 for a typical capacitor in flatband at room temperature. This data combined with measurements of VFB indicates the presence of roughly 1.3 ⋅1012cm−2 positive NOT charges in the oxide near the interface for our samples.

Electrical and Structural Properties of Metal-Oxide-Semiconductor (MOS) Devices with Pt/Ta2O5 Gate Stacks

2011 ◽  
Vol E94-C (5) ◽  
pp. 846-849
Author(s):  
Hoon-Ki LEE ◽  
S.V. Jagadeesh CHANDRA ◽  
Kyu-Hwan SHIM ◽  
Jong-Won YOON ◽  
Chel-Jong CHOI
Keyword(s):  
Metal Oxide ◽  
Structural Properties ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Gate Stacks ◽  
Mos Devices

A Versatile Biological Amplifier

1975 ◽  
Vol 41 (2) ◽  
pp. 371-374
Author(s):  
Thomas W. Roberts
Keyword(s):  
Input Impedance ◽  
Low Cost ◽  
Complementary Metal Oxide Semiconductor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
High Input ◽  
High Input Impedance ◽  
Common Mode Rejection Ratio ◽  
Rejection Ratio ◽  
Mos Devices

A biological amplifier using N-channel and complementary metal-oxide-semiconductor (MOS) devices has been described. Its high input impedance and excellent common mode rejection ratio suit it well to surface and wire EMG research. Its low cost and ease of assembly make it a desirable choice for student use.

scholarly journals Synchrotron radiation photoemission studies of core level excitation effects

1979 ◽  
Vol 89 (1-3) ◽  
pp. 606-614 ◽  
Author(s):  
G.P. Williams ◽  
G.J. Lapeyre ◽  
J. Anderson ◽  
F. Cerrina ◽  
R.E. Dietz ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Core Level ◽  
Synchrotron Radiation Photoemission
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