Methods and devices for evaluating beam blur in subfields projection-exposed by a charged-particle-beam microlithography apparatus

In an imaging-performance measurement system of a charged-particle-beam (CPB) microlithography apparatus, a device for determining beam blur in a subfield of a pattern transfer-exposed by the CPB microlithography apparatus, the device comprising:

• a plate disposed on a wafer stage of the CPB-microlithography apparatus;
• and
• multiple knife-edge reference marks defined by the plate and separated from corresponding beamlets by a relative distance, the relative distance progressively increasing for each successive reference mark defined by the plate.

In an imaging-performance measurement system of a charged-particle-beam (CPB) microlithography apparatus, a device for determining beam blur in a subfield of a pattern transfer-exposed by the CPB microlithography apparatus, the device comprising:

• a reticle stage for holding a reticle comprising multiple subfields, the reticle stage defining an object plane in which multiple measurement marks are defined, each measurement mark being configured to form a respective beamlet from a charged particle beam incident on the object plane;
• and
• a plate disposed on a wafer stage of the CPB-microlithography apparatus, the plate defining multiple knife-edge reference marks separated from the object plane by a relative distance, the relative distance progressively increasing for each successive reference mark defined by the plate.