Patent Number: 
Section: claims

1. A method of forming an image of a sample based on a secondary signal caused by scanning the sample with a charged particle beam, comprising:performing a first scan and a second scan of the sample, the second scan having a faster scan speed than the first scan;obtaining a plurality of images based on the first and second scans;calculating a relative displacement between the plurality of images; andreproducing one image by the first scan based on a result of the calculation. 2. A method of forming an image of a sample according to claim 1, wherein the relative displacement is calculated using pixels of a portion of images obtained by the first and second scans. 3. A method of forming an image of a sample according to claim 1, wherein the first scan is performed prior to the second scan, 4. A charged particle beam apparatus for obtaining an image of a sample, comprising:a charged particle beam source that emits a charged particle beam;a deflector that scans the charged particle beam on the sample;a detector that detects a secondary signal caused by the scan;an image processor that calculates relative deformation or displacement between images obtained by performing first and second scans, the second scan having a faster scan speed than the first scan, and reproducing one image by the first scan based on a result of the calculation. 5. A charged particle beam apparatus for obtaining an image of a sample according to claim 4, wherein said image processor calculates the relative deformation of displacement using pixels of a portion of an image obtained by the first and second scans. 6. A charged particle beam apparatus for obtaining an image of a sample according to claim 4, wherein said first scan is performed prior to said second scan.