Temperature Dependent Analysis of the Pulsed MOS Capacitor for Semiconductor Material Characterization

The Au/Ti/HfO2/[Formula: see text]-GaAs metal/insulating layer/semiconductor structures have been fabricated using standard thermal atomic layer deposition. We experimentally showed whether or not the HfO2 interfacial layer grown on the [Formula: see text]-GaAs wafer modifies the barrier height (BH) of the device at the room temperature. Besides, we investigated the measurement based on temperature dependence of the device parameters from the current–voltage ([Formula: see text]–[Formula: see text]) characteristics of the diode in 60–400[Formula: see text]K range with steps of 10[Formula: see text]K. The X-ray photoelectron spectroscopy (XPS) have been carried out to characterize the surfaces of both [Formula: see text]-GaAs wafer and HfO2 thin films. The series resistance value from the temperature-dependent [Formula: see text]–[Formula: see text] characteristics decreased with decreasing temperature, which is a desired positive result for the devices developed from the MOS capacitor. The BH value of 0.94[Formula: see text]eV (300[Formula: see text]K) has been obtained for the device with the HfO2 layer which is a higher value than the value of 0.77[Formula: see text]eV (300[Formula: see text]K) of the device without HfO2 layer. Therefore, we can say that the HfO2 thin layer at the metal/GaAs interface can also be used for the BH modification as a gate insulator for GaAs MOS capacitor and MOSFETs. When the temperature-dependent [Formula: see text]–[Formula: see text] characteristics at low temperatures have been considered, it has been observed that the current prefers to flow through the lowest BHs due to the BH inhomogeneities.

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Uniaxial Wave Propagation in a Viscoelastic Material Using Measured Material Properties

Journal of Applied Mechanics ◽

10.1115/1.3601234 ◽

1968 ◽

Vol 35 (3) ◽

pp. 449-453 ◽

Cited By ~ 16

Author(s):

W. G. Knauss

Keyword(s):

Wave Propagation ◽

Viscoelastic Material ◽

Material Properties ◽

Material Characterization ◽

Wave Speed ◽

Initial Temperature ◽

Initial Step ◽

Shift Factor ◽

Temperature Dependent ◽

The Difference

The dynamic response of a long viscoelastic bar due to a step displacement at the end is considered. Neglecting geometric dispersion, the effect of realistic viscoelastic material properties is studied theoretically. The solution is obtained in the form of a Fourier sine integral, the convergence of which is studied numerically by piecewise integration to produce an alternating series. It is found that the initial step wave propagates with a high velocity corresponding to the glassy modulus of the material and its amplitude decays with time and distance along the rod. From a practical viewpoint the wave front may decay to immeasurable proportions and any measurable disturbance appears to travel thereafter, with a velocity which is smaller than the glassy wave speed. The effect of initial temperature is discussed. It is shown for thermorheologically simple materials that both the time and spatial variable are scaled by the same temperature dependent (shift) factor. As a consequence, the difference of wave propagation in hard and viscoelastic polymers is illustrated. It is also shown that limited material characterization is sufficient for certain dynamic problems. Comparison of the exact solution with two approximations is made.

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Temperature-dependent material characterization of CuZnSe2 thin films

Thin Solid Films ◽

10.1016/j.tsf.2020.137941 ◽

2020 ◽

Vol 701 ◽

pp. 137941

Author(s):

H.H. Gullu ◽

O. Surucu ◽

M. Terlemezoglu ◽

M. Isik ◽

C. Ercelebi ◽

...

Keyword(s):

Thin Films ◽

Material Characterization ◽

Temperature Dependent

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Effect of initial stress on a semiconductor material with temperature dependent properties under DPL model

Microsystem Technologies ◽

10.1007/s00542-017-3326-8 ◽

2017 ◽

Vol 23 (12) ◽

pp. 5587-5598 ◽

Cited By ~ 6

Author(s):

Mohamed I. A. Othman ◽

Ramadan S. Tantawi ◽

Ebtesam E. M. Eraki

Keyword(s):

Initial Stress ◽

Semiconductor Material ◽

Temperature Dependent ◽

Temperature Dependent Properties

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Investigation of the Effects of Sliding on Wheel Tread Damage

Rail Transportation ◽

10.1115/imece2005-82826 ◽

2005 ◽

Cited By ~ 3

Author(s):

Brandon Talamini ◽

Jeff Gordon ◽

A. Benjamin Perlman

Keyword(s):

Material Characterization ◽

Frictional Heating ◽

Failure Criteria ◽

Impact Loads ◽

Temperature Dependent ◽

Contact Loads ◽

Equal Importance ◽

Model Size ◽

Wheel Flat ◽

Temperature Dependent Properties

Wheel tread spalling is the main source of damage to wheel treads and a primary cause for wheel removals from service. Severe frictional heating of the wheel-rail contact patch during sliding causes the formation of martensite, a hard, brittle microstructure. The martensite patches break away from the more resilient bulk of the wheel tread when subjected to contact loads, resulting in spall formation. Prolonged sliding allows a greater volume of wheel tread material to reach extremely high temperatures, which will lead to material ablation and the formation of a slid flat. Such flats are the cause of wheel impact loads, which are extremely damaging to truck components and rail. This paper outlines an approach developed to estimate the effects of sliding on wheel flat formation and the potential severity of spalling. The methodology is described and preliminary results are presented using an intentionally simplified idealization of the wheel-rail contact geometry. Material characterization (temperature-dependent properties and failure criteria) and management of model size are of equal importance to geometric fidelity and are the focus in the early stages of the development of the qualitative model present here.

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(111) Monocrystalline Nickel Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095819 ◽

1972 ◽

Vol 30 ◽

pp. 512-513

Author(s):

T.E. Pratt ◽

R.W. Vook

Keyword(s):

Film Thickness ◽

Deposition Rate ◽

Room Temperature ◽

Narrow Range ◽

High Vacuum ◽

Residual Pressure ◽

Temperature Dependent ◽

Deposition Parameters ◽

Transmission Electron ◽

Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

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