Rational solvent selection strategies to combat striation formation during spin coating of thin films

Research output: Contribution to journalArticle

86 Citations (Scopus)

Abstract

Striation defects in spin-coated thin films are a result of unfavorable capillary forces that develop due to the physical processes commonly involved in the spin-coating technique. Solvent evaporation during spinning causes depletion at the surface of the more volatile solution components while simultaneous viscous out-flow occurs providing the main source of solution thickness reduction during any typical spinning run. The composition changes in the surface layer can either stabilize or destabilize the surface with respect to convective motions within the coating solution. Destabilization (and therefore possible striation formation) happens when the surface composition changes so that a larger surface tension will develop. Thus, a careful cross-referencing of solvent volatility with surface tension effects can help establish solution conditions that will prevent this instability from arising. A plot of solvent vapor pressure (Pv) versus solvent surface tension (σ) is introduced and utilized to help discuss the impact of solvent choice when making coatings via spin coating. One important result is that when desiring to deposit a coating having a surface tension of σsolid, then it is favorable to use a fully miscible solvent that has a higher surface tension (i.e., σliquid > σsolid). More complicated solution mixtures were also examined, including dual-solvent systems and water-containing systems.

Original languageEnglish
Pages (from-to)1145-1154
Number of pages10
JournalJournal of Materials Research
Volume16
Issue number4
Publication statusPublished - Apr 2001

Fingerprint

combat
striation
Spin coating
coating
Thin films
Surface tension
interfacial tension
thin films
Coatings
metal spinning
coatings
Coating techniques
volatility
destabilization
Vapor pressure
Surface structure
vapor pressure
surface layers
Evaporation
depletion

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Rational solvent selection strategies to combat striation formation during spin coating of thin films. / Birnie, Dunbar P.

In: Journal of Materials Research, Vol. 16, No. 4, 04.2001, p. 1145-1154.

Research output: Contribution to journalArticle

@article{f9b02ed3c8934ca181a5ed8341424abd,
title = "Rational solvent selection strategies to combat striation formation during spin coating of thin films",
abstract = "Striation defects in spin-coated thin films are a result of unfavorable capillary forces that develop due to the physical processes commonly involved in the spin-coating technique. Solvent evaporation during spinning causes depletion at the surface of the more volatile solution components while simultaneous viscous out-flow occurs providing the main source of solution thickness reduction during any typical spinning run. The composition changes in the surface layer can either stabilize or destabilize the surface with respect to convective motions within the coating solution. Destabilization (and therefore possible striation formation) happens when the surface composition changes so that a larger surface tension will develop. Thus, a careful cross-referencing of solvent volatility with surface tension effects can help establish solution conditions that will prevent this instability from arising. A plot of solvent vapor pressure (Pv) versus solvent surface tension (σ) is introduced and utilized to help discuss the impact of solvent choice when making coatings via spin coating. One important result is that when desiring to deposit a coating having a surface tension of σsolid, then it is favorable to use a fully miscible solvent that has a higher surface tension (i.e., σliquid > σsolid). More complicated solution mixtures were also examined, including dual-solvent systems and water-containing systems.",
author = "Birnie, {Dunbar P}",
year = "2001",
month = "4",
language = "English",
volume = "16",
pages = "1145--1154",
journal = "Journal of Materials Research",
issn = "0884-2914",
publisher = "Materials Research Society",
number = "4",

}

TY - JOUR

T1 - Rational solvent selection strategies to combat striation formation during spin coating of thin films

AU - Birnie, Dunbar P

PY - 2001/4

Y1 - 2001/4

N2 - Striation defects in spin-coated thin films are a result of unfavorable capillary forces that develop due to the physical processes commonly involved in the spin-coating technique. Solvent evaporation during spinning causes depletion at the surface of the more volatile solution components while simultaneous viscous out-flow occurs providing the main source of solution thickness reduction during any typical spinning run. The composition changes in the surface layer can either stabilize or destabilize the surface with respect to convective motions within the coating solution. Destabilization (and therefore possible striation formation) happens when the surface composition changes so that a larger surface tension will develop. Thus, a careful cross-referencing of solvent volatility with surface tension effects can help establish solution conditions that will prevent this instability from arising. A plot of solvent vapor pressure (Pv) versus solvent surface tension (σ) is introduced and utilized to help discuss the impact of solvent choice when making coatings via spin coating. One important result is that when desiring to deposit a coating having a surface tension of σsolid, then it is favorable to use a fully miscible solvent that has a higher surface tension (i.e., σliquid > σsolid). More complicated solution mixtures were also examined, including dual-solvent systems and water-containing systems.

AB - Striation defects in spin-coated thin films are a result of unfavorable capillary forces that develop due to the physical processes commonly involved in the spin-coating technique. Solvent evaporation during spinning causes depletion at the surface of the more volatile solution components while simultaneous viscous out-flow occurs providing the main source of solution thickness reduction during any typical spinning run. The composition changes in the surface layer can either stabilize or destabilize the surface with respect to convective motions within the coating solution. Destabilization (and therefore possible striation formation) happens when the surface composition changes so that a larger surface tension will develop. Thus, a careful cross-referencing of solvent volatility with surface tension effects can help establish solution conditions that will prevent this instability from arising. A plot of solvent vapor pressure (Pv) versus solvent surface tension (σ) is introduced and utilized to help discuss the impact of solvent choice when making coatings via spin coating. One important result is that when desiring to deposit a coating having a surface tension of σsolid, then it is favorable to use a fully miscible solvent that has a higher surface tension (i.e., σliquid > σsolid). More complicated solution mixtures were also examined, including dual-solvent systems and water-containing systems.

UR - http://www.scopus.com/inward/record.url?scp=0035322557&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0035322557&partnerID=8YFLogxK

M3 - Article

VL - 16

SP - 1145

EP - 1154

JO - Journal of Materials Research

JF - Journal of Materials Research

SN - 0884-2914

IS - 4

ER -