Patent ID: 9287087
Filing Date: 2016-03-15
CPC Classification: H01J

Claim Text:
1. A sample observation method for observing an observation surface of a sample by irradiation of a charged particle beam, the method comprising: placing a sample stage at a first tilt angle with respect to the charged particle beam, and irradiating the observation surface with the charged particle beam to acquire a first charged particle image; tilting the sample stage to a second tilt angle different from the first tilt angle about a first sample stage axis, and irradiating the observation surface with the charged particle beam to acquire a second charged particle image; comparing an area of the observation surface in the first charge particle image with an area of the observation surface in the second charged particle image; calculating, as a result of the comparison, a tilt angle as an optimum tilt angle of the sample stage at which the area of the observation surface in the charged particle image is the largest among first charged particle image and the second charged particle image; tilting the sample stage to the calculated optimum tilt angle; and irradiating the observation surface with the charged particle beam to observe the observation surface.