Theory of Schottky-Contact Formation on GaAs (110)

1991 ◽  
Vol 240 ◽  
Author(s):  
K. B. Kahen
Keyword(s):  
Room Temperature ◽  
Schottky Contact ◽  
Surface Region ◽  
Phenomenological Theory ◽  
Compound Formation ◽  
Contact Formation ◽  
Barrier Heights ◽  
Relative Enthalpy ◽  
High Metal ◽  
Low Coverage

ABSTRACTA phenomenological theory of Schottky contact formation to GaAs (110) surfaces at room temperature is discussed. The theory splits into two regimes, low- and high-metal coverages. In the low-coverage regime the movement of the Fermi level is proposed to occur because of universal derelaxation of the GaAs (110) surface. For large metal depositions, the resulting barrier heights are hypothesized to be determined by the interaction of either free (not involved in compound formation with other species) metal or free As with the GaAs surface region. It is shown that based on simple considerations of the relative enthalpy of metal-arsenide formation, it is possible to decide which species is responsible for the barrier height and, thus, to account for the majority of barrier heights to the GaAs (110) surface.

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Ni∕Al0.2Ga0.8N interfacial reaction and Schottky contact formation using high quality epitaxial layers

2008 ◽  
Vol 103 (5) ◽  
pp. 053708 ◽  
Author(s):  
B. Boudjelida ◽  
I. Gee ◽  
J. Evans-Freeman ◽  
S. A. Clark ◽  
T. G. G. Maffeis ◽  
...  
Keyword(s):  
Interfacial Reaction ◽  
Schottky Contact ◽  
Epitaxial Layers ◽  
High Quality ◽  
Contact Formation

Defect Structure of MEV Si Implantation in GaAs

1988 ◽  
Vol 126 ◽  
Author(s):  
S.-Tong Lee ◽  
G. Braunstein ◽  
Samuel Chen
Keyword(s):  
Free Surface ◽  
Defect Structure ◽  
Room Temperature ◽  
Surface Region ◽  
Peak Position ◽  
Lattice Disorder ◽  
Depth Profiles ◽  
Trim Calculation ◽  
Good Agreement

ABSTRACTThe defect and atomic profiles for MeV implantation of Si in GaAs were investigated using He++ channeling, TEM, and SIMS. Doses of 1–10 × 1015Si/cm2 at 1–3 MeV were used. MeV implantation at room temperature rendered only a small amount of lattice disorder in GaAs. Upon annealing at 400°C for 1 h or 800°C for 30 a, we observed a ‘defect-free’ surface region (- 1 μ for 3 MeV implant). Below this region, extensive secondary defects were formed in a band which was 0.7 μ wide and centered at 2 μ for 3 MeV implant. These defects were mostly dislocations lying in the [111] plane. SIMS depth profiles of Si implants showed the Si peak to be very close to the peak position of the defects. The experimental profiles of Si were compared to the TRIM calculation; generally good agreement existed among the peak positions.

Theory of Schottky-contact formation on GaAs(110)

1991 ◽  
Vol 43 (14) ◽  
pp. 11745-11753 ◽  
Author(s):  
K. B. Kahen
Keyword(s):  
Schottky Contact ◽  
Contact Formation

Structure and Phase Stability of NiMnGa Ferromagnetic Shape Memory Alloys by Experimental and Ab Initio Techniques

2010 ◽  
Vol 638-642 ◽  
pp. 2040-2045 ◽  
Author(s):  
Claude Esling ◽  
Dao Yong Cong ◽  
Jing Bai ◽  
Yu Dong Zhang ◽  
Jean Marc Raulot ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Orientation Relationship ◽  
Room Temperature ◽  
Phenomenological Theory ◽  
Shear Angle ◽  
Martensitic Structure ◽  
Ferromagnetic Shape Memory Alloys ◽  
Austenite Grain ◽  
Ferromagnetic Shape Memory ◽  
Martensitic Variants

This paper summarizes some of our recent results on crystal structure, microstructure, orientation relationship between martensitic variants and crystallographic features of martensitic transformation in Ni-Mn-Ga FSMAs. It was shown that Ni53Mn25Ga22 has a tetragonal I4/mmm martensitic structure at room temperature. The neighboring martensitic variants in Ni53Mn25Ga22 have a compound twinning relationship with the twinning elements K1={112}, K2={11-2}, η1=<11-1>, η2=<111>, P={1-10} and s=0.379. The ratio of the relative amounts of twins within the same initial austenite grain is ~1.70. The main orientation relationship between austenite and martensite is Kurdjumov-Sachs (K-S) relationship. Based on the crystallographic phenomenological theory, the calculated habit plane is {0.690 -0.102 0.716}A (5.95° from {101}A), and the magnitude, direction and shear angle of the macroscopic transformation shear are 0.121, <-0.709 0.105 0.698>A (6.04° from <-101>A) and 6.88°, respectively.

scholarly journals Production and Electrical Properties of a CuZnAlMn(SMA)/p-Si Diode

2021 ◽  
Author(s):  
EMINE ALDIRMAZ ◽  
M. Güler ◽  
E. Güler
Keyword(s):  
Room Temperature ◽  
Schottky Contact ◽  
Phase Identification ◽  
Frequency Interval ◽  
Electrical Measurements ◽  
X Ray ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Type Semiconductor ◽  
Diode Current

Abstract In this study, the Cu-23.37%Zn-13.73%Al-2.92%Mn (at.%) alloy was used. Phase identification was performed with the Scanning electron microscope (SEM), and energy-dispersive X-ray (EDX). We observed in the austenite phase in Cu-23.37%Zn-13.73%Al-2.92%Mn (at.%) alloy. To produce a new Schottky diode, CuZnAlMn alloy was exploited as a Schottky contact on p-type semiconductor silicon substrate. To calculate the characteristics of the produced diode, current-voltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G-V) analyzes were taken at room temperature (300 K), in the dark and under various lights. Using electrical measurements, the diode's ideality factor (n), barrier height (Φb), and other diode parameters were calculated. Besides, the conductance / capacitance-voltage (G/C-V) characteristics of the diode were studied and in a wide frequency interval at room temperature. Also, the capacitance and conductance values strongly ​​ rely on the frequency. From the present experimental results, the obtained diode can be used for optoelectronic devices.

Vibrational analysis of the low resolution absorption spectra of BrClCS and Br2CS

1988 ◽  
Vol 66 (3) ◽  
pp. 359-366 ◽  
Author(s):  
B. Simard ◽  
R. P. Steer ◽  
R. H. Judge ◽  
D. C. Moule
Keyword(s):  
Absorption Spectra ◽  
Room Temperature ◽  
Vibrational Analysis ◽  
Vibrational Frequencies ◽  
Low Resolution ◽  
Barrier Heights ◽  
Vibrational Levels ◽  
Out Of Plane ◽  
The Given

The [Formula: see text] absorption spectra of BrClCS and Br2CS have been photographed under low resolution at room temperature. The electronic origins of BrClCS and Br2CS have been placed at 17116 and 16859 cm−1, respectively. Vibronic analyses show that the molecules are non-planar in their ā states. By fitting quadratic–Gaussian and quadratic–quartic double-minimum potentials to the observed vibrational levels of the out-of-plane manifolds, the equilibrium out-of-plane angles and the barrier heights to molecular inversion have been estimated to be 25 ± 1 deg and 541 ± 10 cm−1 for BrClCS, and 17.5 ± 1 deg and 524 ± 10 cm−1 for Br2CS. In the case of BrClCS, all six ā state vibrational frequencies have been obtained. In the case of Br2CS, only modes 1 (C—S stretch), 2 (symmetric C—Br stretch), 3 (in-plane Br—C—Br scissor), and 4 (out-of-plane bend) are active in the spectrum. Comparisons with other tetraatomic thiocarbonyls support the given assignments.

Supersonic-Free-Jet CVD Growth of Dy-doped Silicon Films for 1.3 Micron LED

2002 ◽  
Vol 715 ◽  
Author(s):  
Shinji Kawai ◽  
Koji Matsutake ◽  
Fumiya Watanabe ◽  
Teruaki Motooka
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Schottky Contact ◽  
Surface Region ◽  
Electrical Measurements ◽  
Free Jet ◽  
Si Nanoparticle ◽  
Doped Silicon ◽  
Cvd Growth ◽  
Donor States ◽  
Average Size

AbstractWe have investigated epitaxial growth of dysprosium (Dy)-doped silicon (Si:Dy) thin films for fabrication of 1.3 μm light-emitting diodes (LEDs) using supersonic-free-jet CVD. The 700-nm-thick Si:Dy films are grown on p+-type, p-type, and n-type Si(100) at a substrate temperature of 800° for 90 min. The doping concentrations of Dy atoms range from 1018 to 1019 cm-3 at the surface region of the film measured by the secondary ion mass spectrometry (SIMS). The particles with average size ~200 nm form at the surface of the film and it suggests the possibility to form Si-nanoparticle (Si quantum dots) from atomic force microscopy (AFM) observation. From the electrical measurements at room temperature, the metal (Al)-Si:Dy junction is a Schottky contact and Dy introduces donor states in Si.

Ohmic Contact Formation Mechanism of Pd-based Contact to p-GaN

2000 ◽  
Vol 622 ◽  
Author(s):  
Dae-Woo Kim ◽  
Joon Cheol Bae ◽  
Woo Jin Kim ◽  
Hong Koo Baik ◽  
Chong Cook Kim ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Formation Mechanism ◽  
Ohmic Contact ◽  
Room Temperature ◽  
Schottky Barrier Height ◽  
Contact Formation ◽  
Ohmic Behavior ◽  
Plane Direction ◽  
Ohmic Contact Formation

ABSTRACTWe have investigated surface treatment effect on the interfacial reaction of Pd/p-GaN interface and also room temperature ohmic contact formation mechanism of Pd-based ohmic contact. In order to examine room temperature ohmic behavior, various metal contact systems were deposited and current-voltage measurements were carried out. In spite of large theoretical Schottky barrier height between Pd and p-GaN, Pd-based contact showed perfect ohmic characteristic even before annealing. According to the results of synchrotron X-ray radiation, the closed-packed atomic planes (111) of the Pd film were quite well ordered in surface normal direction as well as in the in-plane direction. The effective Schottky barrier height of Au/Pd/Mg/Pd/p-GaN was 0.47eV, which was estimated by Norde method. This discrepancy between theoretical barrier height and the measured one might be due to the epitaxial growth of Pd contact metal and so the room-temperature ohmic characteristic of Pd-based ohmic contact was related strongly to the in-plane epitaxial quality of metal on p-GaN.

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