A semiconductor wafer inspection tool and a semiconductor wafer inspection
method capable of conducting an inspection under appropriate conditions
in any one of an NVC (Negative Voltage Contrast) mode and a PVC (Positive
Voltage Contrast) mode is provided. Primary electrons 2 are irradiated
onto a wafer to be inspected 6 and the irradiation position thereof is
scanned in an XY direction. Secondary electrons (or reflected electrons)
10 from the wafer to be inspected 6 are controlled by a charge control
electrode 5 and detected by a sensor 11. An image processor converts a
detection signal from the sensor 11 to a detected image, compares the
detected image with a predetermined reference image, judges defects, an
overall control section 14 selects inspection conditions from recipe
information for each wafer to be inspected 6 and sets a voltage to be
applied to the charge control electrode 5. A Z stage 8 sets the distance
between the wafer to be inspected 6 and the charge control electrode 5
according to this voltage.