Method for controlling a plasma process
Embodiments of the disclosure relate to apparatus and method for a tunable plasma process within a plasma processing chamber. In one embodiment of the disclosure, a heater assembly for a plasma processing chamber is disclosed. The heater assembly includes a resistive heating element, a first lead coupling the resistive heating element to an RF filter and a tunable circuit element operable to adjust an impedance between the resistive heating element and the RF filter. Another embodiment provides a method for controlling a plasma process in a plasma processing chamber by forming a plasma from a process gas present inside the plasma processing chamber and adjusting an impedance between a resistive heating element and an RF filter coupled between the resistive heating element and a power source for the resistive heating element, while the plasma is present in the plasma processing chamber.
1. A method for controlling a plasma process in a plasma processing chamber comprising:
forming a plasma from a process gas present inside the plasma processing chamber, the plasma processing chamber comprising a tunable circuit element connected between an RF filter and a resistive heating element;
detecting a characteristic of a match circuit coupled to the plasma processing chamber, the characteristic being at least one of voltage and current; and
adjusting a position of the tunable circuit element along a grounded busbar plate to adjust a position of a node and a distance between the tunable circuit element and the RF filter along a lead to adjust an impedance of the tunable circuit element, wherein the tunable circuit element has a first end directly electrically connected to the lead at the node between the resistive heating element and the RF filter and a second end coupled to the grounded busbar plate, wherein adjusting the position of the tunable circuit element comprises moving the tunable circuit element from one of a plurality of apertures disposed along a length of the grounded busbar plate to another of the plurality of apertures along the length of the busbar plate.
2. The method of claim 1 further comprising changing a capacitance of the tunable circuit element to adjust the impedance between the resistive heating element and the RF filter.
3. The method of claim 1 , wherein the tunable circuit element comprises a capacitor, and wherein adjusting the position of the tunable circuit element along the lead relative to the RF filter comprises:
changing a distance between the capacitor and the RF filter.
4. The method of claim 1 , comprising implanting, etching, or depositing a material on substrates in presence of the plasma.
5. The method of claim 4 , wherein adjusting the impedance between the resistive heating element and the RF filter comprises:
controlling a center-to-edge processing result.
6. The method of claim 1 , further comprising:
applying power to the resistive heating element.
7. The method of claim 6 , wherein the resistive heating element is configured to heat a substrate support or a component of the plasma processing chamber.
8. The method of claim 1 wherein the RF filter is coupled between the resistive heating element and a power source for the resistive heating element.