Method for applying a photoresist layer to a substrate having a preexisting topology
AssigneeSandia National Laboratories
InventorsAlfredo M. Morales, Marcela Gonzales
Life of this patent
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Abstract
The present invention describes a method for preventing a photoresist layer from delaminating, peeling, away from the surface of a substrate that already contains an etched three dimensional structure such as a hole or a trench. The process comprises establishing a saturated vapor phase of the solvent media used to formulate the photoresist layer, above the surface of the coated substrate as the applied photoresist is heated in order to “cure” or drive off the retained solvent constituent within the layer. By controlling the rate and manner in which solvent is removed from the photoresist layer the layer is stabilized and kept from differentially shrinking and peeling away from the substrate.
Claims10
A method for preventing a photoresist layer from peeling off a substrate surface having a preexisting structure, comprising the step of:
- providing a substrate surface having a 3-dimensional structure covering at least portion of said surface;
- coating said substrate surface with a liquid photoresist thereby providing a coated substrate, said photoresist comprising a solvent component;
- partially drying said liquid photoresist to provide an uncured photoresist layer, wherein said uncured photoresist layer retains at least a portion of said solvent component;
- establishing a first atmosphere above said coated substrate wherein said first atmosphere comprises a carrier gas saturated with a vapor phase of said solvent component, and wherein some of said solvent component vapor phase condenses onto said uncured photoresist layer;
- heating said coated substrate to a first temperature chosen to cause said solvent portion of said uncured photoresist layer to evaporate at a rate which would remove all or nearly all of said solvent portion from said uncured photoresist layer within about 15 minutes;
- maintaining said first temperature and first atmosphere for about 5 minutes;
- displacing said first atmosphere with a second atmosphere comprising only said carrier gas
- maintaining said first temperature for about an additional 15 minutes;
- and
- cooling said coated substrate to a second temperature equal to about room temperature while maintaining said second atmosphere, to provide a fully adherent photoresist layer coating said substrate surface.
Dependencies are inferred from the claim text.