Mark position measurement apparatus, charged particle beam writing apparatus, and mark position measurement method

A mark position measurement method comprising:

• irradiating, using a sensor including an irradiator and a photoreceiver, while moving a target object, with a plurality of marks formed thereon, placed on a stage, the target object with a laser beam by the irradiator, receiving by the photoreceiver a reflected light from the target object irradiated with the laser beam, and outputting a height position distribution of a surface of the target object;
• calculating, for each mark of the plurality of marks, a position of a mark candidate signal acquired in a scanned region, by using the height position distribution of the surface of the target object, which is for the each mark and obtained by the sensor by scanning the laser beam over the plurality of marks in a manner intersected with a mark of plurality of marks;
• generating a plurality of combinations by combining mark candidate signals selected one by one from the plurality of marks in a case where a plurality of mark candidate signals are acquired in a scanning direction with respect to at least one of the plurality of marks;
• and
• selecting a combination of mark candidate signals, which are mark signals of the plurality of marks, from the plurality of combinations, by comparing, with a predetermined reference value, relative position information regarding mark candidate signals in a same combination in the plurality of combinations, and outputting, as a position of a mark signal, a position of each mark candidate signal configuring the combination selected.