Overlay

Overlay is a process to align the upper layer with the lower layer. The overlay error is defined as the deviation between these two layers. Overlay error measurement is an imaging process of calculating the deviation on two different overlay marks which mostly are generated by different processes and composed of different materials.

For Overlay measurement, Box-in-Box, Frame-in-Frame, L-Bars, Circle-in-Circle, Cross-in-Cross or customized structures are supported.

Critical Dimension

Optical measurement is a non-contact, non-destructive measurement technique and it is precise and fast. The structure width can be calculated by extracting intensity information from images. The intensity images should be processed to prevent it from interference by noise or deformation.

TZTEK’s metrology system provides the function to eliminate such interference. For structure width which is less than 0.7 μm, UV light can be applied.

Film Thickness

The system is designed to measure thickness of transparent or semitransparent dielectric film(resist) up to three layers. The automatic calibration function is integrated.