Slit double gap buncher and method for improved ion bunching in an ion implantation system

A linear accelerator system for accelerating ions traveling along a path from an entrance end to an exit end in an ion implantation system, the linear accelerator system comprising:

• at least one accelerating module having at least one energizable electrode operatively associated with an accelerator energy source and adapted to create a first alternating electric field to accelerate the ions from a first energy to a second energy;
• and
• an ion buncher for grouping ions along a path between the entrance end and the at least one accelerating module, the ion buncher comprising:
• a first grounded electrode with an elongated slit aperture, forming an entrance aperture for an ion beam with an elongated slit shaped transverse profile;
• a second grounded electrode, with either a slit aperture or circular aperture, located along the ion beam path toward the accelerating module;
• and
• an energizable electrode with an elongated slit aperture located between the first and second grounded electrodes and defining gaps therebetween, and operatively associated with an energy source and adapted to create a modulating electric field in the gaps between the elongated slit aperture energizable electrode and the first and second grounded electrodes, respectively, to provide bunched ions to the at least one accelerating module.

An ion implanter, comprising:

• an ion source adapted to direct charged ions having an initial energy along a path;
• a linear accelerator system having an entrance end and an exit end, comprising:
• at least one accelerating module having at least one energizable electrode operatively associated with an accelerating energy source and adapted to create a first alternating electric field to accelerate the ions from a first energy to a second energy;
• and
• an ion buncher for grouping ions along a path between the entrance end and the at least one accelerating module in the linear accelerator system, the ion buncher comprising:
• a first grounded electrode with an elongated slit aperture, forming an entrance aperture for an ion beam with an elongated slit shaped transverse profile;
• a second grounded electrode, with either a slit aperture or circular aperture, located along the ion beam path toward the accelerating module;
• and
• an energizable electrode with an elongated slit aperture located between the first and second grounded electrodes and defining gaps therebetween, and operatively associated with an energy source and adapted to create a modulating electric field in the gaps between the energizable electrode and the first and second grounded electrodes, respectively, to provide bunched ions to the accelerating module;
• an end station adapted to position a workpiece so that charged ions accelerated to the second energy impact the workpiece;
• and
• a controller coupled to the energy sources and adapted to control the relative amplitude and phase of the electric fields in the linear accelerator system.