Apparatus of electron beam comprising pinnacle limiting plate and method of reducing electron-electron interaction

A method of reducing electron-electron interaction of an electron beam in an apparatus of electron beam, comprising:

• providing an apparatus of electron beam comprising an electron gun 18, an electron optical column 20 below the electron gun 18, and a sample chamber 21 below the column 20, wherein the electron gun 18 comprises a bottom (or lowest) anode 19 and a top (or highest) condenser 24, and wherein the sample chamber 21 has a sample space 22 for placing a specimen under examination or a lithographical workpiece;
• placing a pinnacle limiting plate 23 between the bottom anode 19 and the top condenser 24, wherein the pinnacle limiting plate 23 has at least one current-limiting aperture (230);
• and
• passing an electron beam through the at least one current-limiting aperture 230, wherein a current (ampere) of the electron beam that has passed through the at least one current-limiting aperture 230 remains the same after the electron beam travels through the top condenser 24 and the electron optical column 20 and arrives at the sample space 22.