Photomask transparent substrate protection during removal of opaque photomask defects

A photomask repaired by performing a method comprising:

• coating with photoresist a photomask including a transparent substrate on which an opaque defect is isolated, the photomask also including desired opaque parts;
• backside-exposing the photomask with a light source to expose parts of the photoresist unblocked by the opaque defect and the desired opaque parts from a backside of the photomask;
• removing other parts of the photoresist blocked by the opaque defect and the desired opaque parts from the backside of the photomask, such that the opaque defect and the desired opaque parts are exposed;
• and,
• removing the opaque defect on the transparent substrate of the photomask using a focused ion beam (FIB), the parts of the photoresist unblocked by the opaque defect and the desired opaque parts from the backside of the photomask protecting the transparent substrate from riverbed effects and gallium staining.

A semiconductor device fabricated at least in part by using a photomask repaired by performing a method comprising:

• coating with negative photoresist a photomask including transparent regions, desired opaque regions, and undesired opaque regions;
• backside-exposing the photomask with a light source to expose parts of the negative photoresist unblocked by the desired and the undesired opaque regions;
• developing the negative photoresist to remove other parts of the negative photoresist blocked by the desired and the undesired opaque regions from the backside of the photomask to expose the desired and the undesired opaque regions;
• removing the undesired opaque regions using a focused ion beam (FIB), the parts of the negative photoresist unblocked by the desired and the undesired opaque regions from the backside of the photomask protecting the transparent regions of the photomask from riverbed effects and gallium staining.