The effects of natural convection and conduction in a zone-melting-recrystallization chamber

Zone-melting recrystallization (ZMR) with a graphite strip heater is used to improve the material quality of thin film structures for microelectronic applications. The process takes place in a sealed chamber filled with an inert gas such as argon or helium. The effect of natural convection and conduction at the interface between the gas and film structure was studied both numerically and experimentally. Numerical simulations of the temperature profile in the film structure, and the flow pattern and temperature field in the gas were developed. Experimental observations in a scaled setup using a liquid medium verified the flow patterns calculated from the numerical model of the gas flow in the chamber. Results indicated that the gas is stagnant in the region below the strip heater; consequently, conduction from the strip heater to the wafer is prevalent. Outside the stagnant region, natural convection cools the film structure. These two effects combine to create a steeper thermal gradient across the entire wafer which can increase the thermal stresses in the film. The magnitude of this thermal gradient depends strongly on the thermal diffusivity of the gas. The configuration of the strip heater may significantly affect the amount of heat conduction in the stagnant region.

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Preliminary study of inert gas flow analysis on thermal systems with natural convection conditions

Journal of Physics Conference Series ◽

10.1088/1742-6596/1481/1/012020 ◽

2020 ◽

Vol 1481 ◽

pp. 012020

Author(s):

R Anshari ◽

Mairizwan ◽

A Asrizal ◽

A Akmam

Keyword(s):

Natural Convection ◽

Gas Flow ◽

Flow Analysis ◽

Inert Gas ◽

Thermal Systems ◽

Preliminary Study

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Solidification Interface Instabilities During Zone Melting Recrystallization Processing of Multilayer thin Film Structures

MRS Proceedings ◽

10.1557/proc-237-615 ◽

1991 ◽

Vol 237 ◽

Author(s):

Sharon M. Yoon ◽

Christopher K. Hess ◽

Ioannis N. Miaoulis

Keyword(s):

Thin Film ◽

Optical Properties ◽

Phase Change ◽

Local Heat ◽

Zone Melting ◽

Film Structure ◽

Silicon On Insulator ◽

Interface Instability ◽

Property Variation ◽

Solidification Interface

ABSTRACTThis paper describes a stability analysis of the solidification interface during graphite-strip zone-melting-recrystallization of Silicon-On-Insulator thin film structures. The study focused on instabilities induced by i) variations in the optical properties due to thickness perturbations in the structure and ii) changes in optical properties during phase change. Reflective and emissive interference effects between multilayers play a significant role in the temperature distributions during processing. The presence of a step perturbation imbedded within the film structure affects local heat absorption and resulting temperature profiles. Such disturbances that trigger instabilities at the solid-liquid interface were investigated numerically. Processing speeds which cause interface instability due to optical property variation during phase change were identified.

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p-Si(100)/InGaN thin film structure and investigation of its physical properties: N2 gas flow effect

Materials Today Proceedings ◽

10.1016/j.matpr.2019.06.675 ◽

2019 ◽

Vol 18 ◽

pp. 1868-1874

Author(s):

Erman Erdoğan ◽

Mutlu Kundakçı ◽

Ahmet Emre Kasapoğlu ◽

Emre Gür

Keyword(s):

Thin Film ◽

Physical Properties ◽

Gas Flow ◽

Film Structure ◽

Flow Effect ◽

Thin Film Structure

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Effect of Various Parameters on the Bead Geometry and Flexural Strength of MIG Welded Joint

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.c8098.019320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 555-559

Keyword(s):

Flexural Strength ◽

Gas Flow ◽

Flow Direction ◽

Inert Gas ◽

Bead Geometry ◽

Arc Current ◽

The Cost ◽

Torch Angle ◽

Work Effect

Metal inert gas welding is the process in which a continuous coil of consumable electrode is used with inert gas shielding. It was extensively being used for Aluminum and Mg Alloys. But due to other alternatives available for, the cost of inter gas prohibited the use of MIG welding of steels. After the introduction of carbondioxide as shielding gas the economical viability in welding of steels was realized. The quality of weld joing and its productivity is influenced by the parameters such as arc current, wire feed rate, voltage, welding speed, torch angle, , nozzle to plate distance, welding position and gas flow direction. In the present work effect of gas flow rate, voltage and current are studied using Taguchi L-9 orthogonal array. The flexural strength, tensile strenght and bead geometry for various trails are computed and the optimum combination is obtained.

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Fission Gas Bubbles in Fractured UO2

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101177 ◽

1968 ◽

Vol 26 ◽

pp. 286-287

Author(s):

O. M. Katz

Keyword(s):

Electron Microscopy ◽

Thermal Gradient ◽

Gas Bubbles ◽

Inert Gas ◽

Thermal Gradients ◽

Fission Gas ◽

Beam Heating ◽

Limited Application ◽

Bubble Characteristics ◽

Electron Beam Heating

The swelling of irradiated UO2 has been attributed to the migration and agglomeration of fission gas bubbles in a thermal gradient. High temperatures and thermal gradients obtained by electron beam heating simulate reactor behavior and lead to the postulation of swelling mechanisms. Although electron microscopy studies have been reported on UO2, two experimental procedures have limited application of the results: irradiation was achieved either with a stream of inert gas ions without fission or at depletions less than 2 x 1020 fissions/cm3 (∼3/4 at % burnup). This study was not limited either of these conditions and reports on the bubble characteristics observed by transmission and fractographic electron microscopy in high density (96% theoretical) UO2 irradiated between 3.5 and 31.3 x 1020 fissions/cm3 at temperatures below l600°F. Preliminary results from replicas of the as-polished and etched surfaces of these samples were published.

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The effect of an aluminum heat-sink layer on the laser-induced amorphization of SiOx/TeGeSn/SiOx phase-change recording films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154846 ◽

1989 ◽

Vol 47 ◽

pp. 574-575

Author(s):

Matthew R. Libera ◽

Martin Chen

Keyword(s):

Thin Film ◽

Phase Change ◽

Heat Sink ◽

Multilayer Film ◽

Glassy Phase ◽

Film Structure ◽

Glass Forming ◽

Active Storage ◽

Dielectric Layers ◽

Amorphous States

Phase-change erasable optical storage is based on the ability to switch a micron-sized region of a thin film between the crystalline and amorphous states using a diffraction-limited laser as a heat source. A bit of information can be represented as an amorphous spot on a crystalline background, and the two states can be optically identified by their different reflectivities. In a typical multilayer thin-film structure the active (storage) layer is sandwiched between one or more dielectric layers. The dielectric layers provide physical containment and act as a heat sink. A viable phase-change medium must be able to quench to the glassy phase after melting, and this requires proper tailoring of the thermal properties of the multilayer film. The present research studies one particular multilayer structure and shows the effect of an additional aluminum layer on the glass-forming ability.

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