Method and apparatus for improved ion bunching in an ion implantation system

Abstract

An ion buncher stage for a linear accelerator system is disclosed for bunching ions in an ion implantation system. The ion buncher stage may be employed upstream of one or more linear accelerator stages such that the loss of ions in the linear accelerator system is reduced. The invention further includes an asymmetrical double gap buncher stage, as well as a slit buncher stage for further improvement of ion implantation efficiency. Also disclosed are methods for accelerating ions in an ion implanter linear accelerator.

Description

technical field [0001] This invention relates generally to ion implantation systems and, more particularly, to methods and apparatus for improving ion clustering in ion implantation systems. Background technique [0002] In the manufacture of semiconductor devices, ion implantation is used to incorporate impurities into semiconductors. A high energy (HE) ion implanter is described in US Patent 4,667,111, assigned to the assignee of the present invention, and incorporated herein by reference in its entirety. This high-energy ion implanter is used for deep implantation of substrates to produce, for example, some inverted wells. For such deep implants, an implant energy of 1.5 MeV (million electron volts) is typical. Typical implant energies for this type of injector are at least between 300KeV and 700KeV, although lower energies can be used. Certain high-energy ion implanters can deliver ion beams with energies up to 5 MeV. [0003] Referring to FIG. 1 , a typical high ene...

AI Technical Summary

Problems solved by technology

In conventional systems, perhaps around 80% of the ions generated by the ion source are lost (e.g., do not reach the workpiece), thus taking more time to complete the required implant

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