Abstract
Using color video observation in conjunction with careful thickness calibration with laser interferometry it is possible to map the thickness profile evolution with time for fluid flowing radially outward on a rotating silicon wafer during spin coating. During the latest stages of a transparent fluid thinning on a spinning substrate, the fluid reaches thickness values such that interference effects cause the film to display distinct colors that correlate directly to thickness. These colors cycle through the visible spectrum in a predictable and meaningful way. The present work demonstrates that these colors can be easily captured using standard video equipment and that the corresponding thickness values can be calibrated using simultaneous normal-incidence laser interferometry at the center of the substrate. The combination of these two techniques allows for observation of the spinning wafer to understand fluid thickness profile evolution without being forced to know the exact illumination conditions or refractive index dispersion relationship for the fluid being examined. This technique provides meaningful time-resolved thickness profiles for fluids in the later stage of spin deposition and has potentially wider application in engineering process control and coating characterization.
| Original language | English |
|---|---|
| Pages (from-to) | 533-537 |
| Number of pages | 5 |
| Journal | Optics and Lasers in Engineering |
| Volume | 48 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2010 |
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Keywords
- Colorimetry
- Interferometry
- Spin coating
- Thickness monitoring
- Thin films
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
- Atomic and Molecular Physics, and Optics
- Mechanical Engineering
Cite this
Laser interferometric calibration for real-time video color interpretation of thin fluid layers during spin coating. / Birnie, Dunbar P.; Haas, Dylan E.; Hernandez, Carissa M.
In: Optics and Lasers in Engineering, Vol. 48, No. 5, 05.2010, p. 533-537.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Laser interferometric calibration for real-time video color interpretation of thin fluid layers during spin coating
AU - Birnie, Dunbar P.
AU - Haas, Dylan E.
AU - Hernandez, Carissa M.
PY - 2010/5
Y1 - 2010/5
N2 - Using color video observation in conjunction with careful thickness calibration with laser interferometry it is possible to map the thickness profile evolution with time for fluid flowing radially outward on a rotating silicon wafer during spin coating. During the latest stages of a transparent fluid thinning on a spinning substrate, the fluid reaches thickness values such that interference effects cause the film to display distinct colors that correlate directly to thickness. These colors cycle through the visible spectrum in a predictable and meaningful way. The present work demonstrates that these colors can be easily captured using standard video equipment and that the corresponding thickness values can be calibrated using simultaneous normal-incidence laser interferometry at the center of the substrate. The combination of these two techniques allows for observation of the spinning wafer to understand fluid thickness profile evolution without being forced to know the exact illumination conditions or refractive index dispersion relationship for the fluid being examined. This technique provides meaningful time-resolved thickness profiles for fluids in the later stage of spin deposition and has potentially wider application in engineering process control and coating characterization.
AB - Using color video observation in conjunction with careful thickness calibration with laser interferometry it is possible to map the thickness profile evolution with time for fluid flowing radially outward on a rotating silicon wafer during spin coating. During the latest stages of a transparent fluid thinning on a spinning substrate, the fluid reaches thickness values such that interference effects cause the film to display distinct colors that correlate directly to thickness. These colors cycle through the visible spectrum in a predictable and meaningful way. The present work demonstrates that these colors can be easily captured using standard video equipment and that the corresponding thickness values can be calibrated using simultaneous normal-incidence laser interferometry at the center of the substrate. The combination of these two techniques allows for observation of the spinning wafer to understand fluid thickness profile evolution without being forced to know the exact illumination conditions or refractive index dispersion relationship for the fluid being examined. This technique provides meaningful time-resolved thickness profiles for fluids in the later stage of spin deposition and has potentially wider application in engineering process control and coating characterization.
KW - Colorimetry
KW - Interferometry
KW - Spin coating
KW - Thickness monitoring
KW - Thin films
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U2 - 10.1016/j.optlaseng.2009.12.021
DO - 10.1016/j.optlaseng.2009.12.021
M3 - Article
VL - 48
SP - 533
EP - 537
JO - Optics and Lasers in Engineering
JF - Optics and Lasers in Engineering
SN - 0143-8166
IS - 5
ER -