Scanned beam dose rate measurement for ion beam optimization

A method of measuring and optimizing dose rate variation in an ion implantation system including an ion source from which a spot beam is extracted, a scanner which scans the spot beam in a first direction to create a scanned beam directed at a movable workpiece holder adapted to support a semiconductor workpiece, a movable beam profiler having a profiler head movable in the first direction, and beam shaping components adapted to change a shape of the spot beam and a shape of the scanned beam, the method comprising:

• generating the scanned beam according to a beam recipe provided to the ion implantation system;
• moving the profiler head across the scanned beam, the profiler head including a current sensing array comprising at least one current sensing device adapted to measure a dose rate of the scanned beam for generating a scanned beam profile of the scanned beam;
• identifying peak current values across the scanned beam profile and deriving a first dose rate profile therefrom;
• comparing at least one metric associated with the first dose rate profile to at least one corresponding dose rate variation target to determine whether the first dose rate profile is sufficiently uniform;
• and
• if the first dose rate profile is not sufficiently uniform, adjusting settings of the beam shaping components so that the scanned beam has a second dose rate profile that is more uniform than the first dose rate profile.