Patent ID: 6888149

Claim:
A method for correcting a beam irradiation position during processing in a focused ion beam apparatus, the method comprising: a first step of forming a linear line pattern on a sample by linearly irradiating a focused ion beam on a sample at a location removed from a processing region to be processed by irradiation of the focused ion beam; a second step of measuring a position of the linear line pattern in a direction perpendicular to the linear line pattern before processing; a third step of measuring at least once a position of the linear line pattern in a direction perpendicular to the linear line pattern; a fourth step of detecting a drift of the position of the linear line pattern measured by the third step in the direction perpendicular to the linear line pattern with respect to the position measured by the second step or the previously measured position; and a fifth step of correcting the beam irradiation position of the focused ion beam based on the drift detected in the fourth step and processing the processing region.