Dosimetry cup charge collection in plasma immersion ion implantation

摘要

Method and apparatus for causing ions to impact a workpiece implantation surface (14a). A process chamber (12) defines a chamber interior (42) into which one or more workpieces (14) can be inserted for ion treatment. An energy source (40) sets up an ion plasma within the process chamber (12). A support (30) positions one or more workpieces (14) within an interior region (42) of the process chamber (12) so that an implantation surface (14a) of the one or more workpieces (14) is positioned within the ion plasma. A pulse generator (50) in electrical communication with the workpiece support (30) applies electrical pulses for attracting ions to the support (30). One or more dosimetry cups (60) including an electrically biased ion collecting surface (69) are disposed around the workpiece support (30) to measure implantation current. An implantation controller (185) monitors signals from the one or more dosimetry cups (60) to control ion implantation of the workpiece (14).