Methods and systems for determining a fault in a gas heater channel

A method for determining a fault in a gas heater channel, comprising:

• receiving from one or more sensors measured parameters associated with a first plurality of heater elements of the gas heater channel, wherein the gas heater channel is configured to transfer one or more gases from a gas supply to a plasma chamber;
• calculating a measured parallel resistance of the first plurality of heater elements from the measured parameters associated with the first plurality of heater elements;
• comparing the measured parallel resistance of the first plurality of heater elements to an ideal parallel resistance of the first plurality of heater elements of the gas heater channel;
• determining based on the comparison that the first plurality of heater elements is operational;
• receiving from the one or more sensors measured parameters associated with a second plurality of heater elements of the gas heater channel, wherein the second plurality of heater elements are coupled in series to form a plurality of series-coupled heater elements, wherein a first one of the plurality of series-coupled heater elements is coupled via a connector to a second one of the plurality of series-coupled heater elements;
• calculating a measured parallel resistance of the plurality of series-coupled heater elements from the measured parameters associated with the plurality of series-coupled heater elements;
• comparing the measured parallel resistance of the plurality of series-coupled heater elements to an ideal parallel resistance of the plurality of series-coupled heater elements of the gas heater channel;
• determining based on the comparison that the plurality of series-coupled heater elements is inoperational;
• and
• selecting an identity of one of the heater elements of the plurality of series-coupled heater elements from a correspondence between a plurality of identities and the measured parallel resistance of the plurality of series-coupled heater elements, wherein the selection of the identity facilitates identification of a portion of the gas heater channel having the fault.

A system for determining a fault in a gas heater channel, comprising:

• an alternating current (AC) source configured to generate AC power;
• a rectifier coupled to the AC source and configured to convert the AC power into pulsing direct current (DC) power;
• a transistor;
• a gate drive coupled to the rectifier and to the transistor and configured to drive the transistor;
• a channel of heater elements, wherein the heater elements are coupled in series to form a plurality of series-coupled heater elements, wherein a first one of the plurality of series-coupled heater elements is coupled via a connector to a second one of the plurality of series-coupled heater elements;
• a current sensor coupled to the transistor and to the plurality of series-coupled heater elements and configured to sense a current provided to the plurality of series-coupled heater elements, wherein the current is provided when the transistor is driven,
• wherein each of the plurality of series-coupled heater elements has a first node and a second node;
• a voltage sensor coupled to the first node of the plurality of series-coupled heater elements and the second node of the plurality of series-coupled heater elements and configured to measure voltage across each of the plurality of series-coupled heater elements;
• a processor coupled to the voltage sensor and the current sensor, the processor configured to:
• receive the voltage measured by the voltage sensor and the current sensed by the current sensor;
• calculate a parallel resistance of the plurality of series-coupled heater elements from the voltage and the current;
• determine whether the calculated parallel resistance is within a pre-determined threshold of an ideal parallel resistance of the plurality of series-coupled heater elements;
• determine that a portion of the channel is inoperational upon determining that the calculated parallel resistance is not within the pre-determined threshold of the ideal parallel resistance;
• and
• select an identity of the first one of the plurality of series-coupled heater elements from a correspondence between a plurality of identities and the calculated parallel resistance, wherein the selection of the identity facilitates identification of the portion of the channel having the fault.