A photomask for use in a lithographic process and a method of making a photomask
are disclosed. A mask blank including a substrate, a sacrificial conductive layer
disposed over the substrate and a radiation shielding layer disposed over the sacrificial
conductive layer can be provided. Structures are then formed from the radiation
shielding layer to define a pattern. Measurement of parameters associated with
the structures are made with a measurement tool and, during the measuring, the
sacrificial conductive layer provides a conductive plane to dissipate charge transferred
to the mask by the measurement tool.