Patent ID: 7465922

Claim:
An electron beam apparatus for inspecting or reviewing a manufactured substrate, the apparatus comprising: a cathode at a cathode voltage; an extraction electrode at an extraction voltage, wherein the extraction voltage is positive relative to the cathode voltage, such that electrons are emitted from the cathode; a lens electrode at a lens voltage, wherein the lens voltage is positive relative to the extraction voltage, such that electrons are accelerated from the extraction electrode to the lens electrode while the electrons are condensed to form an electron beam, further wherein the lens electrode includes a base section, a focusing-field generation section, and a connecting section which connects the base section and the focusing-field generation section; and an anode with an opening through which the electron beam is transmitted, wherein the anode includes a base section and a field generation section, further wherein the field generation section of the anode is configured with an elongated dimension which lies parallel to the connecting section of the lens electrode; deflectors configured to controllably deflect the electron beam to scan the electron beam over an area of the substrate; electron lenses configured to focus the electron beam onto a spot on a surface of the substrate; and a detector configured to detect secondary electrons from the substrate so as to form an image of the scanned area.