![]() In order to maximize transmission of the accelerated ion beam through the tandem accelerator, the ion beam must be transported through the stripper which is located at the nominal center of the tandem accelerator. The protons emerge from the tandem accelerator with twice the energy of the high positive voltage applied to the tandem accelerator. ![]() The resulting positive hydrogen ion (proton) is again accelerated as it passes to ground potential from the high positive potential. The electrons on the negative hydrogen ions are then stripped from the negative ion by passage through a charge exchange region, the stripper. In a typical tandem acceleration process, an electrostatic accelerator accelerates negative hydrogen ions generated in an ion source from ground potential up to a positive high-voltage terminal. Often tandem acceleration is applied to hydrogen ions in order to generate high energy ions sufficient for deep implants into a substrate. Conversely, certain devices fabricated for use in power applications, for example, require deeper impurity implantation necessitating a high energy hydrogen ion beam.įor these high energy implantation applications, typically 750 kV or greater, tandem acceleration is often used to generate ions having the required energy. For example, certain devices require shallow transistor junctions necessitating low energy ion beams for implantation. The depth of implantation is determined by the energy of the ions directed toward the substrate. ![]() Depending on the type of device being fabricated using ion implantation, the impurity ions may need to be implanted at various depths within the crystalline lattice. The energetic ions in the beam penetrate into the sub-surface of the substrate material and are embedded into the crystalline lattice to form a region of desired conductivity or material property. A desired impurity material is ionized in an ion source, the ions are accelerated to form an ion beam of prescribed energy, and the ion beam is directed at the surface of the substrate. Ion implantation is a standard technique for introducing property-altering impurities into substrates. More particularly, the present invention relates to a hybrid electrostatic lens for use in high energy ion implantation systems. 30, 2012, and entitled “Hybrid Electrostatic Lens for Improved Beam Transmission.” FIELDĮmbodiments of the invention relate to the field of ion implantation for forming semiconductor structures. This application claims priority to the commonly-owned U.S.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |