| 摘要 |
PURPOSE:To magnify the field of observation in making the largest scanning point separate from an axial center, by forming a crossover intermediate image in space between a second scanning coil and an objective lens, while making the image incident into the objective lens in a state of parallelism with an electron beam as an axis. CONSTITUTION:Selecting a minimal magnification with a magnification setter 15, the magnification of a condenser lens 2 is set to be small while that of an objective lens is set to be large and furthermore, a channel selector 12 is turned to a contact (b) side and a stop 6 is removed from an electron beam channel. Then, a crossover intermediate image is formed in a point A' between a second scanning coil 4 and the objective lens 5, while an electron beam is deflected toward outside an axis with a first scanning coil 3, then turned back in parallel with the axis with the second scanning coil 4 and a crossover image is formed at a point C' on a sample 7. Accordingly, the nearer the point A' to the objective lens 5 side the farther the maximum scanning point from the axial center, so that the field of observation can be sharply magnified. |
