Resist Strip

The photoresist is treated by an implantation process beforehand. Several million foreign atoms adhere to the molecular structure of the photoresist. This creates a strong crust that is difficult to remove.

Positive photoresist forms a horizontally linked structure. Light-exposed areas are removed to pattern the surface. Consequently, it is the easiest type of photoresist to remove

Negative photoresist forms a stable type of resist due to its vertical and horizontal crosslinked structure. Non-light-exposed areas are removed to pattern the surface.

Occasionally, the patterning of photoresist isn’t perfect. Consequently, the photoresist has to be removed and reapplied.

The photoresist stripping process uses ozone, promoting sustainability. It combines DI water with ozone gas to remove photoresist effectively. Two steps ensure efficient removal.

This type of photoresist is treated either by a long and hot bake to harden it for critical downstream processes. Due to its treatment, it’s hard to remove.