One of the key challenges of photomask manufacture is to achieve defect-free masks. Clean and repair has been applied
to manage defects and particles on the mask imported during manufacturing processes. Since photomask patterns
become smaller and more complicated as integrated circuit (IC) scaling to 28 nm node and below, the increasingly
importance of mask quality compels us continuously research on more effective defect treatment solutions, to achieve
mask yield enhancement and on-schedule delivery.
In this paper, we would like to introduce new approaches of defect management with dry treatment assistance, according
to particular defect types. One is using plasma etching gases of Cl2/O2 to change the properties of glue compounds
adhering to the mask surface, and make them removed by conventional cleaning. Another is the application of O2
plasma dry treatment for the benefit of alleviation on scan damage phenomenon, which comes from contamination on the
scan area due to excessive repair cycles.