Reasons: the thickness of spin-coated photoresist is related to the wavelength of exposure light source (different exposure wavelengths correspond to different photoresist types and resolutions): I line is the thickest, about 0.7 ~ 3 microns; The thickness of KrF is about 0.4 ~ 0.9 micron; The thickness of ArF is about 0.2 ~ 0.5 μ m.

Yellow light irradiation avoids the possibility of acid or crosslinking after illumination.

The key parameters to determine the thickness of photoresist coating are: the viscosity of photoresist, the lower the viscosity, the thinner the photoresist thickness; Rotation speed, the faster the speed, the thinner the thickness.

Extended data

1. excimer lithography, as the mainstream lithography technology at present, mainly includes: 248nmKrF excimer laser technology with the characteristic size of 0. 1μm; 193nmArF excimer laser technology, feature size 90nm 193nmArF immersion technology (193i), feature size 65nm.

2. The process of photoresist is complex and varied. According to its chemical reaction mechanism and development principle, it can be divided into negative glue and positive glue. It is negative glue that forms insoluble matter after illumination; On the contrary, it is insoluble in some solvents. It is a positive adhesive and becomes soluble after illumination.

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