In-situ electric field detection method and apparatus

An electric field measurement system, comprising:

• a first light source configured to transmit electromagnetic energy at one or more wavelengths;
• a first light sensor configured to receive the electromagnetic energy transmitted at the one or more wavelengths;
• at least one electro-optic sensor, comprising:
• a package comprising a body;
• a first electro-optic crystal disposed within the body;
• and
• at least one optical fiber configured to:
• transmit the electromagnetic energy transmitted from the first light source to a surface of the first electro-optic crystal;
• and
• transmit at least a portion of the electromagnetic energy that was transmitted to the surface of the first electro-optic crystal and subsequently passed through at least a portion of the first electro-optic crystal to the first light sensor,
• wherein the first light sensor is configured to generate a signal that varies based on an attribute of the portion of the electromagnetic energy received by the first light sensor from the at least one optical fiber;
• wherein the attribute is a strength of an electric field over time within a region of a processing chamber;
• and
• a controller, wherein the controller has a processor configured to execute computer-readable instructions that cause the system to:
• apply, by use of a pulsed voltage (PV) waveform generator, a first voltage waveform to a first electrode,
• measure, by use of the at least one electro-optic sensor, the strength of an electric field over time within the region of the processing chamber;
• and
• alter a pulse voltage (PV) waveform generated by the pulse voltage (PV) waveform generator based on the measured electric field strength.

An electric field measurement system, comprising:

• a first light source configured to transmit electromagnetic energy at one or more wavelengths;
• a first light sensor configured to receive the electromagnetic energy transmitted at the one or more wavelengths;
• at least one electro-optic sensor, comprising:
• a package comprising a body;
• a first electro-optic crystal disposed within the body;
• and
• at least one optical fiber configured to:
• transmit the electromagnetic energy transmitted from the first light source to a surface of the first electro-optic crystal;
• and
• transmit at least a portion of the electromagnetic energy that was transmitted to the surface of the first electro-optic crystal and subsequently passed through at least a portion of the first electro-optic crystal to the first light sensor,
• wherein the first light sensor is configured to generate a signal that varies based on an attribute of the portion of the electromagnetic energy received by the first light sensor from the at least one optical fiber;
• wherein the at least one electro-optic sensor is disposed within an RF match that has an input coupled to an output of an RF generator and an output adapted for coupling to an electrode disposed within a processing chamber, wherein the at least one electro-optic sensor is positioned to detect an electric field generated by one or more components within the RF match;
• and
• a controller configured to receive the generated signal from the first light sensor and generate a command signal based on the received signal.

An electric field measurement system, comprising:

• a first light source configured to transmit electromagnetic energy at one or more wavelengths;
• a first light sensor configured to receive the electromagnetic energy transmitted at the one or more wavelengths;
• at least one electro-optic sensor, comprising:
• a package comprising a body;
• a first electro-optic crystal disposed within the body;
• and
• at least one optical fiber configured to:
• transmit the electromagnetic energy transmitted from the first light source to a surface of the first electro-optic crystal;
• and
• transmit at least a portion of the electromagnetic energy that was transmitted to the surface of the first electro-optic crystal and subsequently passed through at least a portion of the first electro-optic crystal to the first light sensor,
• wherein the first light sensor is configured to generate a signal that varies based on an attribute of the portion of the electromagnetic energy received by the first light sensor from the at least one optical fiber;
• wherein the at least one electro-optic sensor is positioned adjacent to a portion of a RF coil disposed within a processing chamber, wherein the at least one electro-optic sensor is positioned to detect an electric field generated by at least a portion of the RF coil during a process performed in the processing chamber;
• and
• a controller configured to receive the generated signal from the first light sensor and generate a command signal based on the received signal.

A method of performing an electric field measurement using an electric field measurement system, comprising:

• detecting, by use of a first electro-optic sensor, an electric field generated by a first component, wherein the first electro-optic sensor comprises:
• a package comprising a body;
• a first electro-optic crystal disposed within the body and positioned so that the generated electric field passes through at least a portion of the first electro-optic crystal;
• and
• at least one optical fiber;
• transmitting, by use of a first light source, electromagnetic energy through the at least one optical fiber to a surface of the first electro-optic crystal while the electric field generated by a first component;
• transmitting at least a portion of the electromagnetic energy, which was transmitted to the surface of the first electro-optic crystal and subsequently passed through at least a portion of the first electro-optic crystal, through the at least one optical fiber to a first light sensor;
• generating, by the first light sensor, a first measurement signal that varies based on an attribute of the portion of the electromagnetic energy received by the first light sensor from the at least one optical fiber;
• wherein generating the first measurement signal comprises:
• generating a first portion of the first measurement signal during a first period of time;
• and
• generating a second portion of the first measurement signal during a second period of time, wherein the electric field generated by the first component is generated during the first period of time and no electric field is generated by the first component during the second period of time;
• and
• generating, by a controller, a command signal based on the generated first measurement signal, wherein generating the command signal based on the generated first measurement signal further comprises:
• comparing the first portion of the measurement signal and the second portion of the measurement signal;
• and
• altering the command signal used to adjust a setting of a processing parameter based on the comparison, wherein the command signal is configured to provide information that is used to adjust a setting of a processing parameter of a process performed in a processing chamber, and wherein the processing parameter comprises altering a first voltage waveform generated by a pulse voltage (PV) waveform generator or an RF waveform generated by a radio frequency (RF) generator.