Numerical Model for Multilayer Thin Films Irradiated by a Moving Laser Source

A two-dimensional transient analysis of the conjugate optical-thermal fields induced in a multilayer thin film structure on a glass substrate by a moving Gaussian laser source is carried out numerically. The workpiece is considered semi-infinite along the motion direction and its optical and thermophysical properties are assumed temperature dependent. The COMSOL Multiphysics 3.3 code has been used to solve the combined thermal and electromagnetic problem. The optical field is considered locally one dimensional and Maxwell equations are solved in order to evaluate the absorption in thin film. Results, in terms of transient temperature profiles and fields, are presented for different Peclet numbers and starting point of the heat source with respect to the workpiece boundary along the motion direction.

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Numerical Investigation on Transient Conjugate Optical-Thermal Fields in Thin Films Irradiated by Moving Sources for Front Treatments

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.1439 ◽

2010 ◽

Vol 297-301 ◽

pp. 1439-1444

Author(s):

Nicola Bianco ◽

Oronzio Manca ◽

Daniele Ricci

Keyword(s):

Thin Film ◽

Maxwell Equations ◽

Film Structure ◽

Laser Source ◽

Transient Temperature ◽

Temperature Profiles ◽

Temperature Dependent ◽

Motion Direction ◽

One Dimensional ◽

Thermal Fields

In this paper a numerical analysis on two-dimensional transient of the combined optical-thermal fields caused by a moving Gaussian laser source in a multilayer thin film structure on a glass substrate is carried out. The workpiece is considered semi-infinite along the motion direction and its optical and thermophysical properties are assumed temperature dependent. The COMSOL Multiphysics 3.4 code has been used to solve the combined thermal and electromagnetic problem. In this way, the optical field is considered locally one-dimensional and Maxwell equations are solved in order to evaluate the absorption in thin film. Results, in terms of transient temperature profiles and fields, are presented for different Peclet numbers and thin film thicknesses.

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Microscale Radiation Effects in Multilayer Thin-Film Structures During Rapid Thermal Processing

MRS Proceedings ◽

10.1557/proc-303-217 ◽

1993 ◽

Vol 303 ◽

Cited By ~ 3

Author(s):

Peter Y. Wong ◽

Christopher K. Hess ◽

Ioannis N. Miaoulis

Keyword(s):

Thin Film ◽

Numerical Model ◽

Thermal Processing ◽

Radiation Effects ◽

Rapid Thermal Processing ◽

Chemical Vapor ◽

Film Structure ◽

Transient Temperature ◽

Multilayered Structures ◽

Temperature Distributions

ABSTRACTThe individual film thicknesses of multilayered structures processed by rapid thermal processing are of the same order as the wavelengths of the incident radiation. This induces optical interference effects which are responsible for the strong dependency of surface reflectivity, emissivity, and temperature distributions on the geometry of the layering structures, presence of patterns, and thickness of the films. A two-dimensional, finitedifference numerical model has been developed to investigate this microscale radiation phenomena and identify the critical processing parameters which affect rapid thermal processing of multilayer thin films. The uniformity of temperature distributions throughout the wafer during rapid thermal processing is directly affected by incident heater configurations, ramping conditions, wafer-edge effects, and thin-film layering structure. Results from the numerical model for various film structures are presented for chemical vapor deposition of polycrystalline silicon over oxide films on substrate. A novel technique using an edge-enhanced wafer which has a different film structure near its edge is presented as a control over the transient temperature distribution.

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Transient Heat Conduction in Solids Irradiated by a Moving Heat Source

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.283-286.358 ◽

2009 ◽

Vol 283-286 ◽

pp. 358-363 ◽

Cited By ~ 7

Author(s):

Nicola Bianco ◽

Oronzio Manca ◽

Sergio Nardini ◽

Salvatore Tamburino

Keyword(s):

Three Dimensional ◽

Transient Heat Conduction ◽

Laser Source ◽

Comsol Multiphysics ◽

Work Piece ◽

Temperature Profiles ◽

Moving Heat Source ◽

Gaussian Laser Beam ◽

Motion Direction ◽

Thermal Fields

Transient three-dimensional temperature distribution in a solid irradiated by a moving Gaussian laser beam was investigated numerically by means of COMSOL Multiphysics 3.3. The investigated work-piece are simply brick-type solids. A laser source is considered moving with constant velocity along the motion direction. The solid dimension along the motion direction is assumed as semi-infinite while width and thickness are considered finite. Several different grid distributions are tested to ensure that the calculated results are grid independent. Typical parameters involved in the processes for any particular application should be evaluated, in order to optimize the material processing and forecast the solid behavior. The results are presented in terms of temperature profiles and thermal fields are given for some Biot and Peclet numbers.

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Effect of Impinging Jet on Heat Conduction in Workpieces Irradiated by a Moving Heat Source

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.312-315.924 ◽

2011 ◽

Vol 312-315 ◽

pp. 924-928 ◽

Cited By ~ 1

Author(s):

N. Bianco ◽

Oronzio Manca ◽

Sergio Nardini ◽

Salvatore Tamburrino

Keyword(s):

Radiative Heat ◽

Three Dimensional ◽

Impinging Jet ◽

Laser Source ◽

Comsol Multiphysics ◽

Finite Width ◽

Moving Heat Source ◽

Temperature Dependent ◽

Motion Direction ◽

Biot Numbers

A three dimensional conductive field is analyzed and solved by means of the COMSOL Multiphysics code. The investigated work-pieces are made up of a simple brick-type solid. A laser source with combined donut-Gaussian distributions is considered moving with a constant velocity along motion direction. The solid dimension along the motion direction is assumed to be infinite or semi-infinite, while finite width (2ly) and thickness (s) are considered. Thermal properties are considered temperature dependent and the materials are considered isotropic. Surface heat losses toward the ambient are taken into account. Several convective heat flux values on the upper surface, with corresponding Biot numbers, and Peclet numbers are considered with negligible radiative heat losses.Results are presented in terms of profile temperatures to evaluate the effect of impinging jet.

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Effect of Solid Thickness on Transient Heat Conduction in Workpieces Irradiated by a Moving Heat Source

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.1445 ◽

2010 ◽

Vol 297-301 ◽

pp. 1445-1450 ◽

Cited By ~ 5

Author(s):

Nicola Bianco ◽

Oronzio Manca ◽

Sergio Nardini ◽

Salvatore Tamburrino

Keyword(s):

Three Dimensional ◽

Transient Heat Conduction ◽

Surface Heat ◽

Laser Source ◽

Comsol Multiphysics ◽

Finite Width ◽

Moving Heat Source ◽

Temperature Dependent ◽

Motion Direction ◽

Gaussian Distributions

In this paper a three dimensional conductive field is analyzed and solved by means of the COMSOL Multiphysics code. The investigated work-pieces are made up of a simple brick-type solid. A laser source with combined donut-Gaussian distributions is considered moving with a constant velocity along motion direction. The solid dimension along the motion direction is assumed to be infinite or semi-infinite, while finite width (2ly) and thickness (s) are considered. Thermal properties are considered temperature dependent and the materials are considered isotropic. Surface heat losses toward the ambient are taken into account. Results are presented in terms of profile temperature to evaluate the effect of solid thickness.

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Effects of High Reynolds Number Impinging Jet on the Heat Conduction in Work-Pieces Irradiated by a Moving Heat Source

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.354.189 ◽

2014 ◽

Vol 354 ◽

pp. 189-194

Author(s):

Oronzio Manca ◽

Sergio Nardini ◽

D. Ricci ◽

S. Tamburrino

Keyword(s):

Three Dimensional ◽

Impinging Jet ◽

Reynolds Numbers ◽

Heat Losses ◽

Laser Source ◽

Finite Width ◽

Temperature Dependent ◽

Motion Direction ◽

Commercial Code ◽

High Reynolds

A three dimensional conductive field is analyzed and solved numerically by means of a commercial code. The investigated work-pieces are made up of a simple brick-type solid. A laser source with combined donut-Gaussian distributions is considered moving with a constant velocity along motion direction. The solid dimension along the motion direction is assumed to be infinite or semi-infinite, while finite width (2ly) and thickness (s) are considered. Thermal properties are considered temperature dependent and the materials are considered isotropic. Surface heat losses toward the ambient are taken into account. Several Reynolds numbers of the impinging jet, Biot and Peclet numbers are considered with negligible radiative heat losses. Results are presented in terms of temperatures field and profile to evaluate the effect of impinging jet.

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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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