Apparatus and method for controlling erosion profile in hollow cathode magnetron sputter source

A hollow cathode magnetron sputter source comprising:

• a cathode target having a sidewall portion and a closed end portion, the sidewall and closed end portions of the target forming a cavity;
• a main magnet positioned adjacent the sidewall portion of the target outside of the cavity, the main magnet producing a main magnetic field having field lines that extend into the cavity;
• and
• a magnet array positioned adjacent the closed end of the target outside of the cavity, the magnet array comprising a plurality of electromagnets, at least one of the magnets in the array producing a magnetic field which aids the main magnetic field, at least one other magnet in the array producing a magnetic field which bucks the main magnetic field.

A method of operating a hollow cathode magnetron sputter source, the sputter source comprising a cathode target having a sidewall portion and a closed end portion and forming a cavity, and a main magnet positioned adjacent the sidewall portion outside of the cavity and producing a main magnetic field that extends into the cavity, the method comprising:

• providing first and second magnet arrays adjacent the closed end portion of the target and outside of the cavity, a first magnetic field produced by the first magnet array aiding the main magnetic field, a second magnetic field produced by the second magnet array bucking the main magnet field;
• reducing the pressure in the sputter source;
• introducing an inert gas into the sputter source;
• applying a negative voltage to the target so as to create a plasma in the cavity;
• and
• rotating the magnet arrays.

A method of operating a hollow cathode magnetron sputter source, the sputter source comprising a cathode target having a sidewall portion and a closed end portion and forming a cavity, and a main magnet positioned adjacent the sidewall portion outside of the cavity and producing a main magnetic field that extends into the cavity, the method comprising:

• providing a plurality of electromagnets adjacent the closed end portion of the target and outside of the cavity;
• reducing the pressure in the sputter source;
• introducing an inert gas into the sputter source;
• applying a negative voltage to the target so as to create a plasma in the cavity;
• and
• turning the electromagnets on and off in sequence to create first and second virtual rotating magnet arrays, the magnetic field produced by the first virtual rotating magnet array aiding the main magnetic field and the magnetic field produced by the second virtual rotating magnet array bucking the main magnetic field.