Numerical prediction of etched profile in pyrolytic laser etching

T. S. Wee, Y. F. Lu, W. K. Chim

Research output: Contribution to journalConference article

Abstract

A quasi-static two-dimensional heat conduction analysis is used to deduce the geometrical profile of a cavity pyrolytically etched on an isotropic silicon substrate by a stationary CW Ar+ laser with a Gaussian intensity profile. Starting with a substrate having a flat surface, the analysis progressively removes regions of the substrate to model the actual etching action. The finite element method is used to solve the non-linear problem iteratively. Multiple reflections of the laser beam in the etched cavity are also modeled assuming that the substrate surface is perfectly diffused. Laser etching experiments performed on a silicon substrate in a CCl4 gas ambient are used to verify the numerical routine. Comparison with the numerical results indicates that the desorption of SiCl2 radicals is probably responsible for the final etched profile obtained. Deposition of the residue from the chemical etching was also observed in the etched cavity. The re-deposition was found to proceed in different manners for stationary and scanning beams. These differing actions of re-deposition are explained in the context of the different temperature distributions induced in the two cases.

Original languageEnglish (US)
Pages (from-to)211-220
Number of pages10
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume3184
DOIs
StatePublished - Dec 1 1997
EventMicroelectronic Packaging and Laser Processing - Singapore, Singapore
Duration: Jun 25 1997Jun 25 1997

Fingerprint

Etching
Substrate
etching
Laser
Lasers
Prediction
Substrates
profiles
predictions
Cavity
lasers
Silicon
cavities
Continuous wave lasers
Desorption
silicon
Temperature Distribution
Heat Conduction
Heat conduction
Laser Beam

Keywords

  • Carbon tetrachloride
  • Diffused reflection
  • Finite element method
  • Heat conduction analysis
  • Laser etched profile
  • Laser induced temperature profile
  • Numerical laser etching model
  • Pyrolytic laser etching
  • Silicon

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Numerical prediction of etched profile in pyrolytic laser etching. / Wee, T. S.; Lu, Y. F.; Chim, W. K.

In: Proceedings of SPIE - The International Society for Optical Engineering, Vol. 3184, 01.12.1997, p. 211-220.

Research output: Contribution to journalConference article

@article{2cab5bd2ef5f4e93960b312176e3a1cb,
title = "Numerical prediction of etched profile in pyrolytic laser etching",
abstract = "A quasi-static two-dimensional heat conduction analysis is used to deduce the geometrical profile of a cavity pyrolytically etched on an isotropic silicon substrate by a stationary CW Ar+ laser with a Gaussian intensity profile. Starting with a substrate having a flat surface, the analysis progressively removes regions of the substrate to model the actual etching action. The finite element method is used to solve the non-linear problem iteratively. Multiple reflections of the laser beam in the etched cavity are also modeled assuming that the substrate surface is perfectly diffused. Laser etching experiments performed on a silicon substrate in a CCl4 gas ambient are used to verify the numerical routine. Comparison with the numerical results indicates that the desorption of SiCl2 radicals is probably responsible for the final etched profile obtained. Deposition of the residue from the chemical etching was also observed in the etched cavity. The re-deposition was found to proceed in different manners for stationary and scanning beams. These differing actions of re-deposition are explained in the context of the different temperature distributions induced in the two cases.",
keywords = "Carbon tetrachloride, Diffused reflection, Finite element method, Heat conduction analysis, Laser etched profile, Laser induced temperature profile, Numerical laser etching model, Pyrolytic laser etching, Silicon",
author = "Wee, {T. S.} and Lu, {Y. F.} and Chim, {W. K.}",
year = "1997",
month = "12",
day = "1",
doi = "10.1117/12.280576",
language = "English (US)",
volume = "3184",
pages = "211--220",
journal = "Proceedings of SPIE - The International Society for Optical Engineering",
issn = "0277-786X",
publisher = "SPIE",

}

TY - JOUR

T1 - Numerical prediction of etched profile in pyrolytic laser etching

AU - Wee, T. S.

AU - Lu, Y. F.

AU - Chim, W. K.

PY - 1997/12/1

Y1 - 1997/12/1

N2 - A quasi-static two-dimensional heat conduction analysis is used to deduce the geometrical profile of a cavity pyrolytically etched on an isotropic silicon substrate by a stationary CW Ar+ laser with a Gaussian intensity profile. Starting with a substrate having a flat surface, the analysis progressively removes regions of the substrate to model the actual etching action. The finite element method is used to solve the non-linear problem iteratively. Multiple reflections of the laser beam in the etched cavity are also modeled assuming that the substrate surface is perfectly diffused. Laser etching experiments performed on a silicon substrate in a CCl4 gas ambient are used to verify the numerical routine. Comparison with the numerical results indicates that the desorption of SiCl2 radicals is probably responsible for the final etched profile obtained. Deposition of the residue from the chemical etching was also observed in the etched cavity. The re-deposition was found to proceed in different manners for stationary and scanning beams. These differing actions of re-deposition are explained in the context of the different temperature distributions induced in the two cases.

AB - A quasi-static two-dimensional heat conduction analysis is used to deduce the geometrical profile of a cavity pyrolytically etched on an isotropic silicon substrate by a stationary CW Ar+ laser with a Gaussian intensity profile. Starting with a substrate having a flat surface, the analysis progressively removes regions of the substrate to model the actual etching action. The finite element method is used to solve the non-linear problem iteratively. Multiple reflections of the laser beam in the etched cavity are also modeled assuming that the substrate surface is perfectly diffused. Laser etching experiments performed on a silicon substrate in a CCl4 gas ambient are used to verify the numerical routine. Comparison with the numerical results indicates that the desorption of SiCl2 radicals is probably responsible for the final etched profile obtained. Deposition of the residue from the chemical etching was also observed in the etched cavity. The re-deposition was found to proceed in different manners for stationary and scanning beams. These differing actions of re-deposition are explained in the context of the different temperature distributions induced in the two cases.

KW - Carbon tetrachloride

KW - Diffused reflection

KW - Finite element method

KW - Heat conduction analysis

KW - Laser etched profile

KW - Laser induced temperature profile

KW - Numerical laser etching model

KW - Pyrolytic laser etching

KW - Silicon

UR - http://www.scopus.com/inward/record.url?scp=57649129507&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=57649129507&partnerID=8YFLogxK

U2 - 10.1117/12.280576

DO - 10.1117/12.280576

M3 - Conference article

AN - SCOPUS:57649129507

VL - 3184

SP - 211

EP - 220

JO - Proceedings of SPIE - The International Society for Optical Engineering

JF - Proceedings of SPIE - The International Society for Optical Engineering

SN - 0277-786X

ER -