Specific Process Knowledge/Characterization/Optical characterization: Difference between revisions
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[[image:Ellipsometer.jpg|275x275px|right|thumb|Ellipsometer: positioned in cleanroom 2]] | [[image:Ellipsometer.jpg|275x275px|right|thumb|Ellipsometer: positioned in cleanroom 2]] | ||
This ellipsometer is a VASE (Variable Angle Spectroscopic Ellipsometry) ellipsometer from J.A. Woollam Co., Inc. | |||
Ellipsometry is a very sensitive characterization technique which can be used to determine thin film layer thicknesses and/or optical constants. It sends in polarized light on the surface at different angles and measures the change in polarization state of the reflected light. | |||
It is especially good for thin films in the thickness range of a few nanometers to a few microns. The layer should be transparent to light in the usable wavelength range for the thickness to be determined. Large roughness (>40nm) and features within the field of view can cause the measurement to fail. | |||
Ellipsometry is an indirect measurement so a model has to be fit to the data in order to obtain the film thickness and optical constants. | |||
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