High mass resolution low aberration analyzer magnet for ribbon beams and the system for ribbon beam ion implanter

摘要

The present invention provides a mass analyzing magnet which can bend a very wide charged particle ribbon beams through angles between 90 to 200 degrees. The shorter dimension of the ribbon beam is aligned with the magnetic field. The magnet can focus the longer dimension of the ribbon beam through a resolving slot inside the magnet for mass or momentum analysis. The magnet pole is shaped to increase the mass resolving power and to provide the focusing force in the direction of the shorter dimension of the ribbon beam. This magnet can achieve high mass resolving power with very small system aberrations for very wide ribbon beam. This feature is of significant value, for example, in the ion implantation industry. The ribbon beam width can be 300 mm, 450 mm and even 1000 mm. Integrated with the present invention, the ion implanter systems can be built to provide mass analyzed ribbon beams for various applications. The system will have much lower cost and much better ribbon beam quality than the ion implanters which are using conventional mass analyzing magnet.