Specific Process Knowledge/Lithography/Coaters: Difference between revisions

After spin coating, the solvent in the resist must be evaporated in a baking step, in order to solidify the resist. This softbake can be carried out as a contact bake or a proximity bake. In a contact bake, the wafer is held in close contact to the hotplate surface, either in direct contact or by resting on shallow bumps (150 µm above the hotplate in the Gamma tools). In a proximity bake, the wafer is first moved into proximity, e.g. 1mm, of the hotplate surface, then held there (on the lift pins) for the duration of the bake.