The method and the device mentioned above are used in connection with photolithography methods by which microstructured components, for example semiconductor chips or microelectromechanical systems (MEMSs), can be produced. A first step of production methods of this type involves coating a substrate (“wafer”) with a photoresist (“resist”). The photoresist is subsequently exposed, for example through a mask, changing to a curtain extent the physical and/or chemical properties of the photoresist. The photoresist can subsequently be removed in part.
Before the photoresist is removed in part, it has to be cured. This may take place in several steps, for example in a pre-curing (“softbake”) before the photoresist is exposed and a subsequent actual curing.
For curing, the substrate coated with the photoresist may be arranged on a heated receptacle (“hotplate”), in such a way that a greater or lesser part of the solvent contained in the photoresist is evaporated under the effect of the supplied heat.
However, it has been found that the photoresist has a different thickness after being cured (in part or in full) even if it was spread uniformly on the substrate during coating. This has a disadvantageous effect on the microstructures subsequently to be produced.
The object of the invention is to provide a method and a device by means of which the photoresist can be cured on the substrate in such a way that it has as uniform a thickness as possible.
USPTO Backgrounds
USPTO Backgrounds