Method of generation of charged particle beam exposure data and charged particle beam exposure method using a block mask

A charged particle beam exposure method, in which a charged particle beam is passed through a rectangular first transmission aperture to form a first transmission beam, the first transmission beam is passed through a block mask having a plurality of discrete patterns to form a second transmission beam, and the second transmission beam irradiates an object for exposure, comprising the steps of:

• irradiating said block mask with said first transmission beam according to data for the irradiation position on said block mask by said first transmission beam, such that a Y-direction or X-direction edge of said first transmission beam is positioned in an X-direction or Y-direction common isolation area of said plurality of discrete patterns of the block mask;
• and
• scanning said first transmission beam over said plurality of discrete patterns of the block mask while irradiating a beam intensity sensor which measures the beam intensity with said second transmission beam, and performing calibration such that said irradiation position data is set to the scanning position at which the change in the intensity detected by said beam intensity sensor is substantially zero.