Sensitivity and Non-linearity of Shipley AZ-1375 Photoresist at 441·6 and 457·9 nm

The characteristic curves for Shipley AZ-1375 photoresist at 441·6 and 457·9 nm are experimentally determined. The relative sensitivities at these wavelengths are also determined. Some important effects which lead to non-linearities at large etch depths are discussed. Absorption of light in the photoresist is identified as contributing most to non-linearities with 441·6 nm illumination, whereas the tendency of the photoresist to saturate at large exposures is the greatest contributor to non-linearities at 457·9 nm.