Optical Density

Optical Density (OD) scanning is a specialized technique used to measure ultra-thin films with thicknesses below 1 μm. It employs a highly stable optical measurement system to estimate a material’s absorption coefficient and absorption thickness. This method is non-contact and non-invasive, making it suitable for high-resolution imaging analysis.

OD optical density scanning is one of the few techniques capable of achieving nanometer-level resolution in thin film thickness measurement. It is particularly well-suited for applications in semiconductor thin-film processing, precision optical coatings, and quality inspection and process control of ultra-thin photoresists. As such, it is considered one of the key technologies in modern precision metrology.

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