Patent ID: 7439525

Claim:
A method for measuring a stage phase in a charged particle beam exposure apparatus, comprising: measuring a rotation angle of a pattern of a charged particle beam shaped through a mask placed on a mask stage of the charged particle beam exposure apparatus and then irradiated on a surface of a specimen through an objective optical system; correcting rotation of the pattern by rotating the mask corresponding to the measured rotation angle; measuring a first stage position of the mask stage in accordance with a mask stage coordinate system after correcting the rotation with an opening portion of the mask being situated in a first opening position; irradiating a first charged particle beam to a first irradiation position on the surface of the specimen through the opening portion of the mask, the first charged particle beam being shaped through the opening portion and then passing through an objective lens system; measuring the first irradiation position in accordance with a specimen stage coordinate system; moving the mask stage to a second stage position to situate the opening portion in a second opening position different from the first opening position; measuring the second stage position of the mask stage in accordance with the mask stage coordinate system; irradiating a second charged particle beam to a second irradiation position on the surface of the specimen through the opening of the mask moved together with the mask stage, the second charged particle beam shaped through the opening portion situated in the second opening position and then passing through the objective lens system; measuring the second irradiation position in accordance with a specimen stage coordinate system; and calculating a phase difference between the specimen stage coordinate system and the mask stage coordinate system from the first and second stage positions and the first and second irradiation positions.