BIPOLAR WAFER CHARGE MONITOR SYSTEM AND ION IMPLANTATION SYSTEM COMPRISING SAME

摘要

A charge monitor having a Langmuir probe is provided, wherein a positive and negative charge rectifier are operably coupled to the probe and configured to pass only a positive and negative charges therethrough, respectively. A positive current integrator is operably coupled to the positive charge rectifier, wherein the positive current integrator is biased via a positive threshold voltage, and wherein the positive current integrator is configured to output a positive dosage based, at least in part, on the positive threshold voltage. A negative current integrator is operably coupled to the negative charge rectifier, wherein the negative current integrator is biased via a negative threshold voltage, and wherein the negative current integrator is configured to output a negative dosage based, at least in part, on the negative threshold voltage. A positive charge counter and a negative charge counter are configured to respectively receive the output from the positive current integrator and negative current integrator in order to provide a respective cumulative positive charge value and cumulative negative charge value associated with the respective positive charge and negative charge.

主权项

1. A charge monitor for an ion implantation system, the charge monitor comprising:
a Langmuir probe; a positive charge rectifier operably coupled to the Langmuir probe and configured to pass only a positive charge therethrough; a positive current integrator operably coupled to the positive charge rectifier, wherein the positive current integrator is biased via a positive threshold voltage, and wherein the positive current integrator is configured to output a positive dosage based, at least in part, on the positive threshold voltage; a positive charge counter configured to receive the output from the positive current integrator and to provide a cumulative positive charge value associated with the positive charge; a negative charge rectifier operably coupled to the Langmuir probe and configured to pass only a negative charge therethrough; a negative current integrator operably coupled to the negative charge rectifier, wherein the negative current integrator is biased via a negative threshold voltage, and wherein the negative current integrator is configured to output a negative dosage based, at least in part, on the negative threshold voltage; and a negative charge counter configured to receive the output from the negative current integrator and to provide a cumulative negative charge value associated with the negative charge.