Non-Ohmic Normal State Behavior and the Onset of Global Superconductivity in Partially Annealed Quench–Condensed Films of Tin

1990 ◽  
Vol 195 ◽  
Author(s):  
Carl A. Shiffman ◽  
Robert S. Markiewicz ◽  
Men Ho
Keyword(s):  
Low Temperature ◽  
Film Thickness ◽  
Sheet Resistance ◽  
Normal State ◽  
State Behavior ◽  
Low Temperature Annealing ◽  
A Value

ABSTRACTFilms of tin condensed onto 4K pyrex substrates can be driven from “insulating” (i.e. dR/dT < 0) to superconducting behavior by low temperature annealing. Global superconductivity occurs when the normul state sheet resistance, R□, shrinks to a value very near R□ ≡ h/4ea, as in experiments where R□ is changed by increasing the film thickness. When R□ > R□, conduction is decidedly non-ohmic, with R□(T,V) = R□(T) + R1 (T)exp(−m(T)|V|).

Sputtered Silicon for Microstructures and Microcavities

1999 ◽  
Author(s):  
Kenneth A. Honer ◽  
Gregory T. A. Kovacs
Keyword(s):  
Surface Roughness ◽  
Electrical Resistivity ◽  
Low Temperature ◽  
Film Thickness ◽  
Plane Stress ◽  
Strain Gradient ◽  
Sacrificial Layer ◽  
Low Temperature Annealing ◽  
Deposition Power ◽  
Density Surface

Abstract Sputtered silicon can be used to make released microstructures at temperatures compatible with prefabricated aluminum-metallized CMOS circuitry. The fabrication sequence is similar to LPCVD polysilicon processes and involves a wet release from an oxide sacrificial layer. This process was used to fabricate a variety of test structures, including cantilevers, combs, and spirals. During release of the structures porosity to HF was observed in films up to 5 μm thick. This porosity resulted in the formation of completely enclosed cavities formed beneath silicon membranes over oxide sacrificial layers, and may have implications for the packaging of released devices. Several properties of the sputtered silicon films were investigated, including their in-plane stress, strain gradient, film density, surface roughness, electrical resistivity, and permeability. The dependency of these properties on deposition power, pressure, and film thickness as well as the effects of low-temperature annealing were also investigated.

Resistance Decrease of Phosphorus Ion Implanted Poly-Si Thin Films During Low Temperature Annealing

1995 ◽  
Vol 403 ◽  
Author(s):  
H. Tokioka ◽  
Y. Masutani ◽  
Y. Goto ◽  
S. Nagao ◽  
H. Kurokawa
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Layer Thickness ◽  
Sheet Resistance ◽  
Lower Layer ◽  
Low Temperature Annealing ◽  
Two Layer Model ◽  
Temperature Activation ◽  
Resistance Decrease ◽  
Ellipsometry Data

AbstractDuring low temperature (below 450°C) annealing, the sheet resistance of phosphorus implanted poly-Si thin films (film thickness : 50nm) decreased to lE+3Ω/square. The sheet resistance after annealing decreased with annealing time and became lower when the dosing level was high enough. At the dose of 8E+14 ions/cm2 we obtained a sheet resistance of 1E+3Q/square by annealing at 450°C for 180min. We analyzed ellipsometry data assuming a two-layer model where the surface layer consists of a-Si and the lower layer of poly-Si. This analysis indicated that the surface of implanted films was amorphized by ion implantation and the amorphized layer thickness increased with dosing level. Also, it turned out that the lower poly-Si layer thickness increased from 30nm to 50nm after annealing accompanied by the conversion of a-Si layer to poly-Si layer. During annealing at low temperature, activation of phosphorus ions implanted into poly-Si and recrystallization of a-Si took place simultaneously and the sheet resistance after annealing decreased with the increase in thickness of the recrystallized region.

Vacancy Enhanced Boron Activation during Room Temperature Implantation and Low Temperature Annealing

2000 ◽  
Vol 610 ◽  
Author(s):  
Jian-Yue Jina ◽  
Irene Rusakova ◽  
Qinmian Li ◽  
Jiarui Liu ◽  
Wei-Kan Chu
Keyword(s):  
Low Temperature ◽  
Sheet Resistance ◽  
Room Temperature ◽  
Activation Barrier ◽  
Promising Method ◽  
Activation Mechanism ◽  
Rich Region ◽  
Shallow Junction ◽  
Low Temperature Annealing ◽  
Junction Formation

AbstractLow temperature annealing combined with pre-damage (or preamorphization) implantation is a very promising method to overcome the activation barrier in ultra-shallow junction formation. We have made a 32 nm p+/n junction with sheet resistance of 290 /sq. using 20 keV 4×1014 Ω/cm2 Si followed by 2 keV 1×1015 at./cm2 B implantation and 10 minutes 550 °C annealing. This paper studies the boron activation mechanism during low temperature annealing. The result shows that placing B profile in the vacancyrich region has much better boron activation than placing B profile in interstitial-rich region or without pre-damage. It also shows that a significant portion of boron is in substitutional positions before annealing. The amount of substitutional boron is correlated to the amount of vacancies (damage) by the pre-damage Si implantation. The result supports our speculation that vacancy enhances boron activation.

Annealing Behavior after Ion Shower Doping for the Fabrication of LTPS-TFTs

2007 ◽  
Vol 124-126 ◽  
pp. 231-234
Author(s):  
Beop Jong Jin ◽  
Joo Yeol Lee ◽  
Jae Sang Ro
Keyword(s):  
Low Temperature ◽  
Sheet Resistance ◽  
Excimer Laser ◽  
Ion Source ◽  
Gas Mixture ◽  
Annealing Behavior ◽  
Low Temperature Annealing ◽  
Uv Transmittance ◽  
Activation Annealing ◽  
Acceleration Voltage

Ion shower doping with a main ion source of P2Hx using a source gas mixture of PH3/H2 was conducted on excimer-laser-annealed (ELA) poly-Si. The amount of as-implanted damage was observed to increase with acceleration voltage. The measured values of as-implanted damage using a UV-transmittance was found to correlate well with the ones calculated using TRIM-code simulation. After activation annealing the sheet resistance generally decreases as the acceleration voltage increases. It, however, increases as the acceleration voltage increases under the conditions of severe doping and low temperature annealing. Results of UV-transmission Spectroscopy and Hall measurements revealed that uncured damage seems to be responsible for the rise in sheet resistance.

Low-temperature annealing of YBa2Cu3O7-x

1992 ◽  
Vol 50 (1) ◽  
pp. 88-89
Author(s):  
R.L. Sabatini ◽  
Yimei Zhu ◽  
Masaki Suenaga ◽  
A.R. Moodenbaugh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Oxygen Diffusion ◽  
Diffusion Rate ◽  
Oxygen Depletion ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Oxygen Diffusion Rate

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

scholarly journals Optimization of Fiber Bragg Gratings Inscribed in Thin Films Deposited on D-Shaped Optical Fibers

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4056
Author(s):  
José Javier Imas ◽  
Carlos R. Zamarreño ◽  
Ignacio del Villar ◽  
Ignacio R. Matías
Keyword(s):  
Thin Film ◽  
Film Thickness ◽  
Optical Fibers ◽  
Flat Surface ◽  
Sno2 Thin Film ◽  
Thin Film Thickness ◽  
A Value ◽  
Surrounding Refractive Index ◽  
Reflected Power ◽  
Fabrication Parameters

A fiber Bragg grating patterned on a SnO2 thin film deposited on the flat surface of a D-shaped polished optical fiber is studied in this work. The fabrication parameters of this structure were optimized to achieve a trade-off among reflected power, full width half maximum (FWHM), sensitivity to the surrounding refractive index (SRI), and figure of merit (FOM). In the first place, the influence of the thin film thickness, the cladding thickness between the core and the flat surface of the D-shaped fiber (neck), and the length of the D-shaped zone over the reflected power and the FWHM were assessed. Reflected peak powers in the range from −2 dB to −10 dB can be easily achieved with FWHM below 100 pm. In the second place, the sensitivity to the SRI, the FWHM, and the FOM were analyzed for variations of the SRI in the 1.33–1.4 range, the neck, and the thin-film thickness. The best sensitivities theoretically achieved for this device are next to 40 nm/RIU, while the best FOM has a value of 114 RIU−1.

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