Process baseline of HMDS
Appropriate equipment is required for the processing of HMDS.
The pre-treatment should be performed immediately prior to resist coating. Generally, hot plates with integrated HMDS-evaporation are used in the production. If this option is not available, the substrate is placed in a desiccator where HMDS evaporates at room temperature or at temperatures up to 160 °C max. HMDS is under these
conditions deposited as monomolecular layer (approx. 5 nm) on the substrate surface.
The treated substrate can be coated with resist immediately after HMDS-deposition without subsequent tempering, or stored in a closed container for a couple of days.
The storage stability may be limited due to an uptake of water from the atmosphere. Storage in open containers should thus be avoided.