Soft-Baking
Soft-baking is the step during which almost all of the solvents are separate from the photo resist coating. Soft-baking plays a very critical role in photo-imaging. The photo resist coatings become photosensitive, or imageable, only after soft baking. Oversoft-baking will degrade the photosensitivity of resists by either decreasing the developer solubility or actually destroying a portion of the sensitizer.