In the field of semiconductor technology, the ion implantation technique generally refers to a technique for performing ion doping on a region near the surface of a semiconductor material. The primary aim of the ion implantation technique is to change the carrier concentration or conduction type of the semiconductor material. The ion implantation apparatus has been widely applied to an ion doping process. Due to its ability to satisfy needs for a shallow junction, low temperature, and accurate control, the ion implantation apparatus has become a key apparatus in the semiconductor fabricating process.
In the ion implantation process, the ion beam generated by an ion source has to go through a plurality of electrodes with a certain aperture ratio to accelerate the ions. The aperture ratio of an electrode refers to a ratio between an area of penetration portions in the electrode and the total area of the electrode. As can be seen, the aperture ratio of the electrode not only determines the utilization efficiency of doped ions, but also affects the density of the ion beam. Accordingly, there is a need for increasing the aperture ratio of electrodes to improve ion implantation efficiency.