Extraction electrode system for high current ion implanter

A variable aperture electrode apparatus, comprising:

• an ion source comprising an extraction electrode, wherein the extraction electrode generally defines an extraction aperture in an outside wall of the ion source, and wherein the extraction electrode is configured to extract ions from the ion source, therein defining an ion beam;
• a suppression electrode positioned downstream of the extraction electrode, wherein the suppression electrode comprises first and second suppression electrode plate disk halves defining a variable suppression aperture therebetween, and wherein a gap is defined along a path of the ion beam between the extraction aperture and suppression aperture;
• a ground electrode positioned downstream of the suppression electrode by a predetermined distance alone the ath of the ion beam wherein the round electrode comprises first and second ground electrode plate disk halves defining a variable ground aperture therebetween, wherein the first suppression electrode plate disk half and first ground electrode plate disk half are generally fixed with respect to one another and are operably coupled to a first support leg, and wherein the second suppression electrode plate disk half and second ground electrode plate disk half are generally fixed with respect to one another and are operably coupled to a second support leg;
• and
• a moving mechanism configured to concurrently translate the suppression electrode and ground electrode along the path of the ion beam along a first axis, wherein the gap between the extraction aperture and suppression aperture is variable based on the translation along the first axis, and wherein the moving mechanism is further configured to translate the first and second suppression electrode plate disk halves with respect to one another and to translate the first and second ground electrode plate disk halves with respect to one another, wherein the translation of the first and second suppression electrode plate disk halves and first and second ground electrode disk plate halves is parallel to a second axis generally perpendicular to the first axis, wherein the moving mechanism is configured to linearly translate the first support leg and second support leg in unison along the first axis, and wherein the moving mechanism is further configured to linearly translate the first support leg and second support leg in opposite directions generally parallel to the second axis, and wherein the first support leg is slidingly coupled to a first support leg track, and wherein the second support leg is slidingly coupled to a second support leg track, wherein the first support leg track and second support leg track are inclined at opposite angular slopes to the first axis, wherein the translation of the first support leg and second support leg along the first axis further translates the first suppression electrode plate disk half and first ground electrode plate disk half with respect to the second suppression electrode plate disk half and second ground electrode plate disk half generally parallel to the second axis.

An ion implantation system, comprising:

• an ion source comprising an arc chamber, wherein the ion source further comprises an extraction electrode generally defining an extraction aperture in an outside wall of the arc chamber, and wherein the extraction electrode is configured to extract ions from the arc chamber, therein defining an ion beam;
• a variable aperture electrode apparatus positioned downstream of the ion source, the variable aperture electrode apparatus comprising:
• a suppression electrode positioned, wherein the suppression electrode comprises first and second suppression electrode plate disk halves defining a variable suppression aperture therebetween, and wherein a gap is defined along a path of the ion beam between the extraction aperture and suppression aperture;
• a ground electrode positioned downstream of the suppression electrode by a predetermined distance along the path of the ion beam, wherein the ground electrode comprises first and second ground electrode plate disk halves defining a variable ground aperture therebetween;
• and
• a moving mechanism configured to concurrently translate the suppression electrode and ground electrode along the path of the ion beam along a first axis, wherein the gap between the extraction aperture and suppression aperture is variable based on the translation along the first axis, and wherein the moving mechanism is further configured to translate the first and second suppression electrode plate disk halves with respect to one another and to translate the first and second ground electrode plate disk halves with respect to one another, wherein the translation of the first and second suppression electrode plate disk halves and first and second ground electrode disk plate halves is parallel to a second axis generally perpendicular to the first axis;
• a beamline assembly positioned downstream of the variable aperture electrode apparatus, wherein the beamline assembly is configured to mass analyze the ion beam;
• and
• an end station positioned downstream of the beamline assembly, wherein the end station is configured to translate a workpiece through the ion beam.

An ion implantation system, comprising:

• an ion source comprising an arc chamber, wherein the ion source further comprises an extraction electrode generally defining an extraction aperture in an outside wall of the arc chamber, and wherein the extraction electrode is configured to extract ions from the arc chamber, therein defining an ion beam;
• a variable aperture electrode apparatus positioned downstream of the ion source, the variable aperture electrode apparatus comprising:
• a suppression electrode positioned, wherein the suppression electrode comprises first and second suppression electrode plate disk halves defining a variable suppression aperture therebetween, and wherein a gap is defined along a path of the ion beam between the extraction aperture and suppression aperture;
• a ground electrode positioned downstream of the suppression electrode by a predetermined distance along the path of the ion beam, wherein the ground electrode comprises first and second ground electrode plate disk halves defining a variable ground aperture therebetween, wherein the first suppression electrode plate disk half and first ground electrode plate disk half are generally fixed with respect to one another and are operably coupled to a first support leg, and wherein the second suppression electrode plate disk half and second ground electrode plate disk half are generally fixed with respect to one another and are operably coupled to a second support leg;
• and
• a moving mechanism configured to concurrently translate the suppression electrode and ground electrode along the path of the ion beam along a first axis, wherein the gap between the extraction aperture and suppression aperture is variable based on the translation along the first axis, and wherein the moving mechanism is further configured to translate the first and second suppression electrode plate disk halves with respect to one another and to translate the first and second ground electrode plate disk halves with respect to one another, wherein the translation of the first and second suppression electrode plate disk halves and first and second ground electrode disk plate halves is parallel to a second axis generally perpendicular to the first axis, and wherein the moving mechanism is configured to linearly translate the first support leg and second support leg in unison along the first axis, and wherein the moving mechanism is further configured to linearly translate the first support leg and second support leg in opposite directions generally parallel to the second axis, wherein the first support leg is slidingly coupled to a first support leg track, and wherein the second support leg is slidingly coupled to a second support leg track, wherein the first support leg track and second support leg track are inclined at opposite angular slopes to the first axis, wherein the translation of the first support leg and second support leg along the first axis further translates the first suppression electrode plate disk half and first ground electrode plate disk half with respect to the second suppression electrode plate disk half and second ground electrode plate disk half generally parallel to the second axis;
• a beamline assembly positioned downstream of the variable aperture electrode apparatus, wherein the beamline assembly is configured to mass analyze the ion beam;
• and
• an end station positioned downstream of the beamline assembly, wherein the end station is configured to translate a workpiece through the ion beam.

A method for controlling ion beam current at an implant location, the method comprising:

• providing an ion source having an extraction electrode in an outside wall of the ion source;
• providing a suppression electrode having a variable suppression aperture downstream of the extraction electrode, wherein a gap between the suppression electrode and the extraction electrode is variable;
• providing a ground electrode having a variable ground aperture downstream of the suppression electrode;
• measuring the ion beam current at the implant location;
• and
• concurrently controlling the gap between the extraction electrode and the suppression electrode, a width of the variable suppression aperture, and a width of the variable ground aperture, based on the measured ion beam current.