Apparatus and method for reduction of particle contamination by bias voltage

An ion implantation system, comprising:

• an ion beam generator configured to generate an ion beam;
• a wafer chuck configured to hold a wafer;
• a Faraday cup configured to receive at least a portion of the ion beam;
• a bias voltage source electrically connected to the Faraday cup, wherein the bias voltage source is configured to apply a bias voltage to the Faraday cup when an ion beam is delivered from the ion beam generator to the wafer and, wherein the bias voltage source is a power supply electrically connected to the Faraday cup;
• a calibration circuit electrically connected to the power supply and a pre-amplifier, wherein the calibration circuit is configured to adjust an amplification level of the pre-amplifier based on the bias voltage;
• and
• a controller electrically connected to the pre-amplifier, wherein the controller is configured to adjust a current of the ion beam based on the amplification level of the pre-amplifier.

An ion implantation system, comprising:

• an ion beam generator configured to generate a ribbon-shaped ion beam;
• a wafer chuck configured to hold a wafer;
• a Faraday cup configured to receive at least a portion of the ion beam;
• a bias voltage source electrically connected to the Faraday cup, wherein the bias voltage source is configured to apply a bias voltage to the Faraday cup when an ion beam is delivered from the ion beam generator to the wafer wherein the bias voltage source is configured to apply the bias voltage based on a desired convergence of the ribbon-shaped ion beam.

A method for reducing particle contamination in an ion implantation system, the ion implantation system including an ion beam generator, a wafer chuck configured to hold a wafer, a Faraday cup, a bias voltage source electrically connected to the Faraday cup, a pre-amplifier electrically connected to the Faraday cup, and a controller electrically connected to the pre-amplifier, the method comprising:

• delivering an ion beam with the ion beam generator to the wafer;
• applying a bias voltage to the Faraday cup with the bias voltage source when an ion beam is delivered from the ion beam generator to the wafer;
• determining a voltage of the Faraday cup with the pre-amplifier;
• and
• adjusting a current of the ion beam with the controller based on the measured voltage of the Faraday cup.

A method for reducing particle contamination in an ion implantation system, the ion implantation system including an ion beam generator, a wafer chuck configured to hold a wafer, a Faraday cup, a bias voltage source electrically connected to the Faraday cup, a calibration circuit electrically connected to the power supply, a pre-amplifier, and a controller electrically connected to the pre-amplifier, wherein the bias voltage source is a power supply electrically connected to the Faraday cup, the method comprising:

• delivering an ion beam with the ion beam generator to the wafer;
• applying a bias voltage to the Faraday cup with the bias voltage source when an ion beam is delivered from the ion beam generator to the wafer;
• adjusting an amplification level of the pre-amplifier with the calibration circuit based on the bias voltage;
• and
• adjusting a current of the ion beam based on the amplification level of the pre-amplifier with the controller.

A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by one or more processors of an ion implantation system, cause the ion implantation system to:

• deliver an ion beam to a wafer held by a wafer chuck of the ion implantation system with an ion beam generator of the ion implantation system;
• apply a bias voltage to a Faraday cup of the ion implantation system with a bias voltage source of the ion implantation system, wherein the bias voltage is applied by the bias voltage source when the ion beam is delivered from the ion beam generator to the wafer;
• measure a voltage of the Faraday cup with a pre-amplifier of the ion implantation system electrically connected to the Faraday cup;
• and
• adjust a current of the ion beam with a controller of the ion implantation system electrically connected to the pre-amplifier, based on the measured voltage of the Faraday cup.

A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by one or more processors of an ion implantation system, cause the ion implantation system to:

• deliver an ion beam to a wafer held by a wafer chuck of the ion implantation system with an ion beam generator of the ion implantation system;
• apply a bias voltage to a Faraday cup of the ion implantation system with a bias voltage source of the ion implantation system, wherein the bias voltage is applied by the bias voltage source when the ion beam is delivered from the ion beam generator to the wafer;
• adjust, based on the bias voltage, an amplification level of a pre-amplifier of the ion implantation system with a calibration circuit of the ion implantation system electrically connected to the power supply and the pre-amplifier;
• and
• adjust a current of the ion beam based on the amplification level of the pre-amplifier with a controller of the ion implantation system electrically connected to the pre-amplifier.