Embodiments of the present disclosure are directed to methods and apparatus, as well as a method for forming such a device for carrying out ion etching on the semiconductor substrate. In some embodiments, the electrode assembly may be manufactured, the electrode assembly comprises a plurality of electrodes with different purposes, and each of the electrode in a stable manner is mechanically fixed to the next electrode. After the electrodes are secured together may be apertures are formed in the electrodes respectively, to thereby ensure that the fine alignment between the electrodes that are neighboring apertures. In some cases, the electrodes are formed from doped silicon degenerate (縮 退), the electrode assembly is held together by electrostatic bonding. Other electrode material and fixing methods may also be used. The electrode assembly may comprise, hollow cathode emitter electrodes in a truncated conical shape or other non-cylindrical aperture may have an aperture shape in some cases. The chamber liner and / or a reflector can also be present in some cases.