Patent ID: 7608821
Filing Date: 2009-10-27
Classification: H01J

Abstract:
1. A substrate inspection apparatus comprising: an electron gun which generates an electron beam to irradiate the electron beam to a substrate; an electron detection unit which detects at least one of a secondary electron, a reflection electron and a back scattering electron generated from a surface of the substrate by the irradiation of the electron beam to output signals constituting an image showing a state of the substrate surface; and a uniform surface potential creating unit which generates ions, and irradiates the ions to the substrate prior to the irradiation of the electron beam to create a uniform surface potential of the substrate: wherein the uniform surface potential creating unit is configured to form a first electric field to guide the ions to the substrate until the surface potential of the substrate becomes a first potential having a preset value and is configured to form a second electric field whose direction is opposite to that of the first electric field to turn back the irradiated ions from the substrate in replacement of the first electric field, when an absolute value of the surface potential of the substrate becomes congruent with or exceeds an absolute value of the first potential.