Apparatus and method for inspecting sample surface

1. A method for inspecting a sample surface with a projection type electron beam inspection apparatus, the method characterized in comprising the steps of:

forming such an irradiation area on the sample surface by an electron beam generated from an electron gun that has approximately a circular or elliptical shape of a size larger than a pattern on the sample surface;

irradiating the electron beam substantially onto a center of the pattern on the sample surface; and

forming an image on an electron detection plane of a detector from secondary electrons emanating from the sample surface in response to the irradiation of the electron beam for inspecting the sample surface.

2. A method for inspecting a sample surface in accordance with claim 1 , characterized in that the detector is an EB-CCD.

3. A method for inspecting a sample surface in accordance with claim 1 or 2 , characterized in that the irradiation of the electron beam onto the sample surface is carried out by deflecting the electron beam by controlling of a voltage of a blanking electrode disposed in the middle of a path of the electron beam,

wherein the method comprises:

calculating an amount of charges, i.e., dose amount, irradiated on the sample surface, by using a blanking signal obtained by the controlling of the voltage of the blanking electrode;

calculating a variation in potential of the sample surface from a predetermined physical constant depending on the dose amount and the structure of the sample; and

adjusting a retarding voltage (RTD) to cancel out the variation in potential.

4. A method for inspecting a sample surface in accordance with claim 3 , characterized in that an irradiation point of the electron beam is shifted from the center of the pattern on the sample surface to a direction substantially opposite to the deflecting direction of the electron beam so as to eliminate a bias in a charged condition of the sample surface.