Diagnostic and control systems and methods for substrate processing systems using DC self-bias voltage
AssigneeNovellus Systems, Inc.
InventorsEdward Augustyniak, Douglas Keil
Life of this patent
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Abstract
A substrate processing system includes a processing chamber including a showerhead, a plasma power source and a pedestal spaced from the showerhead to support a substrate. A filter is connected between the showerhead and the pedestal. A variable bleed current circuit is connected between the filter and the pedestal to vary a bleed current. A controller is configured to adjust a value of the bleed current and configured to perform curve fitting based on the bleed current and DC self-bias voltage to estimate at least one of electrode area ratio, Bohm current, and radio frequency (RF) voltage at a powered electrode.
Claims7
A substrate processing system, comprising:
- a processing chamber including a showerhead, a plasma power source and a pedestal spaced from the showerhead to support a substrate,
- wherein the plasma power source supplies first radio frequency (RF) power to create plasma between the showerhead and the substrate;
- a probe arranged in the plasma;
- a first capacitor;
- an RF power source coupled by the first capacitor to the probe to supply second RF power;
- and
- a controller configured to receive a measurement of a DC self-bias voltage across the first capacitor, receive a measurement of the second RF power supplied by the RF power source, and calculate a film thickness using the measurements of the second RF power and the DC self-bias voltage across the first capacitor.
Dependencies are inferred from the claim text.