Focusing apparatus and lithography system using the same

A lithography system comprising:

• a vacuum chamber surrounding a space into which a wafer is located;
• an electron-beam emitter arranged in the vacuum chamber to face the wafer and to be spaced apart from the wafer by a given interval and emitting an electron beam toward the wafer;
• and
• an electromagnetic focusing apparatus controlling a path of an electron beam generated from the electron-beam emitter,
• the electromagnetic focusing apparatus including:
• a magnetic field generator forming a magnetic field in the vacuum chamber, a portion of the magnetic field generator arranged partially within a boundary of the vacuum chamber,
• wherein a uniformity of the magnetic field in the vacuum chamber may be adjusted through movement of the portion of the magnetic field generator with respect to the vacuum chamber.