Charged particle beam device and optical examination device

A charged particle beam device comprising:

• a stage movable in at least a height direction;
• a projection optical system that projects a first pattern on one side and a second pattern on another side across at least a part of a scanning area of a charged particle beam on a wafer placed on the stage, the first pattern and the second pattern being projected from an oblique direction with respect to a surface of the wafer;
• and
• a detection optical system that detects a light emitted from the projection optical system and reflected by the surface of the wafer,
• wherein, on the wafer, the second pattern is projected to an area on the wafer closer to the projection optical system compared with the first pattern, and the first pattern is projected on one side and the second pattern is projected on another side across a projection of an optical axis of the projection optical system on the surface of the wafer,
• wherein the projection optical system further comprises a plurality of first slits that projects the first pattern via a first slit group, and a plurality of second slits that projects the second pattern via a second slit group, and
• the plurality of first slits are disposed at a first side with respect to the optical axis of the projection optical system, and the plurality of the second slits are disposed at a second side with respect to the optical axis of the projection optical system.

An optical inspection device comprising:

• a stage movable in at least a height direction;
• a projection optical system that projects a first pattern on one side and a second pattern on another side across a field of view on a wafer placed on the stage, the first pattern and the second pattern being projected from an oblique direction with respect to a surface of the wafer;
• and
• an imaging device that obtains images of the first pattern and the second pattern,
• wherein at least one of the images of the first pattern and the second pattern is chosen to adjust a height the stage,
• wherein the projection optical system further comprises a plurality of first slits that projects the first pattern via a first slit group, and a plurality of second slits that projects the second pattern via a second slit group, and
• the plurality of first slits are disposed at a first side with respect to an optical axis of the projection optical system, and the plurality of the second slits are disposed at a second side with respect to the optical axis of the projection optical system.