Focused ion beam apparatus

A method for correcting a beam irradiation position in a focused ion beam apparatus, the method comprising the steps of:

• defining on a sample at least one processing region for conducting fine processing by irradiating a focused ion beam;
• forming a first linear line pattern on the sample by linearly irradiating a focused ion beam on the sample at a location that does not overlap a position of the at least one processing region;
• measuring first brightness changing positions along the first linear line pattern from one side of the first linear line pattern in one direction perpendicular to of the first linear line pattern, and second brightness changing positions along the first linear line pattern from another side of the first linear line pattern in another direction perpendicular to of the first linear line pattern;
• obtaining a first average position of the first and second brightness changing positions measured in one direction perpendicular to the first linear line pattern as a position of the first linear line pattern in a direction perpendicular to the first linear line pattern before processing;
• obtaining at least once the first average position in a direction perpendicular to the first linear line pattern during processing of the processing region;
• detecting a drift in the first average position of the focused ion beam in the direction perpendicular to the first linear line pattern compared to the first average position obtained previously;
• and
• correcting the beam irradiation position of the focused ion beam with respect to at least one processing region based on the drift detected when processing the processing region.

A focused ion beam apparatus, comprising:

• an ion beam source that generates an ion beam;
• an ion lens that focuses the ion beam into a focused ion beam;
• a scanning device that scans the focused ion beam on a specified processing region on a sample surface;
• a component that defines on the sample at least one processing region for conducting a fine processing by irradiating the focused ion beam;
• a component that forms a linear line pattern on the sample by linearly irradiating a focused ion beam on the sample at a location that does not overlap the least one processing region;
• a component that measures first brightness changing positions along the linear line pattern from one side of the linear line pattern in one direction perpendicular to the linear line pattern, and second brightness changing positions along the linear line pattern from another side of the linear line pattern in another direction perpendicular to the linear line pattern;
• a component that obtains an average position of the first and second brightness changing positions measured;
• a component that obtains the average position before or in the process;
• a component that detects a drift in the beam irradiation position of the focused ion beam in the direction perpendicular to the linear line pattern based on a drift of the average position;
• and
• a component that corrects the beam irradiation position of the focused ion bean based on the drift detected with respect to at least one processing region.