Magnetic field fluctuation for beam smoothing

A system for implanting ions in a work piece, the system comprising:

• an ion beam source for providing an ion beam;
• a mass analyzing magnet configured to receive the ion beam and direct the ion beam along an ion beam path toward a work piece;
• a plurality of separately driven electromagnets configured to adjust an ion beam profile of the ion beam;
• and
• one or more separately driven auxiliary electromagnets configured to generate a fluctuating magnetic field;
• wherein the fluctuating magnetic field causes the ion beam profile shape to change continuously to smooth a time-averaged ion beam profile of the ion beam.

A non-transitory computer-readable storage medium containing computer executable instructions for implanting a work piece with ions using an ion implantation tool, the ion implantation tool having an ion beam source, a mass analyzing magnet, a plurality of separately driven electromagnets, and one or more separately driven auxiliary electromagnets, the computer executable instructions comprising instructions for:

• causing the ion beam source to generate a beam of ions;
• causing the plurality of separately driven electromagnets to be driven to generate a magnetic field to shape an ion beam profile of the ion beam;
• causing the one or more separately driven auxiliary electromagnets to be driven with a periodic signal to generate a fluctuating magnetic field,
• wherein the fluctuating magnetic field causes the ion beam profile shape to change continuously to smooth a time-averaged ion beam profile of the ion beam;
• and
• causing the mass analyzing magnet to guide the ion beam along an ion beam path toward a work piece to implant ions on the work piece.

A method of shaping an ion beam, the method comprising:

• subjecting an ion beam to a magnetic field generated by a set of multipole magnets to shape an ion beam profile of the ion beam, wherein each multipole magnet of the set of multipole magnets comprises:
• a laminated core;
• a plurality of separately driven electromagnets wrapped around the laminated core;
• and
• one or more separately driven auxiliary electromagnets wrapped around the laminated core and positioned on an end of the multipole magnet;
• generating a plurality of direct current (DC) drive signals to drive the plurality of electromagnets of each of the set of multipole magnets to generate a quadrupole magnetic field;
• and
• generating one or more periodic drive signals to drive the one or more auxiliary electromagnets of each of the set of multipole magnets to generate a fluctuating magnetic field;
• wherein the fluctuating magnetic field causes the ion beam profile shape to change continuously to smooth a time-averaged ion beam profile of the ion beam.

A system for shaping an ion beam, the system comprising:

• a set of multipole magnets, each multipole magnet of the set of multipole magnets comprising:
• a laminated core;
• a plurality of separately driven electromagnets wrapped around the laminated core;
• and
• one or more separately driven auxiliary electromagnets wrapped around the laminated core and positioned on an end of the multipole magnet;
• and
• a controller for driving the set of multipole magnets;
• wherein the controller is configured to generate:
• a plurality of direct current (DC) drive signals to drive the plurality of electromagnets of each of the set of multipole magnets to generate a quadrupole magnetic field for adjusting an ion beam profile of an ion beam;
• and
• one or more periodic drive signals to drive the one or more auxiliary electromagnets of each of the set of multipole magnets to generate a fluctuating magnetic field;
• wherein the fluctuating magnetic field causes the ion beam profile shape to change continuously to smooth a time-averaged ion beam profile of the ion beam.