Cee® Apogee™ 300 Bake Plate Manual
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4.5. Bake Methods
Another important factor is the method of bake. Cee® hotplates allow for three distinct bake
methods; proximity, soft contact, and hard contact.
In a hard contact bake the substrate is held onto the hotplate surface by the application of vacuum
to the underside of the substrate. Small holes are machined into the hotplate surface in a pattern
which optimizes vacuum distribution without the formation of cold spots or warping of the
substrate. This method is usually preferred for silicon and other flat substrates where back side
contact is not a problem.
Soft contact baking uses gravity alone to hold the substrate onto the hotplate. This method
generally offers less uniformity since the substrate-hotplate thermal interface is not as efficient.
Proximity baking is accomplished by forcing nitrogen through ports in the hotplate surface. This
forces the substrate to float at a distance
