Method of providing changed particle beam exposure in which representative aligning marks on an object are detected to calculate an actual position to perform exposure

A method of providing charged particle beam exposure onto an object having a plurality of chip areas, with a plurality of aligning marks formed in correspondence to each of said chip areas, said method comprising the steps of:

• mounting said object on a mobile stage;
• irradiating a charged particle beam on said object based upon positions of said aligning marks;
• detecting first positions, each of which is a position of a corresponding said aligning mark among different said chip areas, and second positions which are positions of said plurality of aligning marks for each of a plurality of said chip areas;
• determining a first approximate relationship between any actual position of all said aligning marks corresponding to said first positions and a corresponding design position based upon a relationship between said first positions detected and corresponding design positions;
• determining, for each of said chip areas related to said second positions, a second approximate relationship between any actual position within said chip area and a corresponding design position based upon a relationship between said second positions detected and corresponding design positions;
• determining a generalized second approximate relationship between any actual position within any one of said chip areas and a corresponding design position based upon said second approximate relationship for each of said chip areas related to said second positions;
• calculatoing an actual position within one of said chip areas in correspondence to a design position, based upon said first approximate relationship and said generalized second approximate relationship;
• and
• performing exposure based upon said calculated actual position.