WIDE DYNAMIC RANGE ION ENERGY BIAS CONTROL; FAST ION ENERGY SWITCHING; ION ENERGY CONTROL AND A PULSED BIAS SUPPLY; AND A VIRTUAL FRONT PANEL
First Claim
1. A method of operating a plasma processing chamber comprising:
- sustaining a plasma in contact with a substrate on a substrate support within the plasma processing chamber;
accessing an effective capacitance, C1, of the substrate support;
providing a modified periodic voltage function to the substrate support in order to effect a potential on a surface of the substrate, the modified period voltage function formed from a combination of a periodic voltage function and an ion current compensation, IC; and
calculating ion current, II, in the plasma as a function of measurements of the modified periodic voltage function.
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Accused Products
Abstract
This disclosure describes systems, methods, and apparatus for operating a plasma processing chamber. In particular, a periodic voltage function combined with an ion current compensation can be provided as a bias to a substrate support as a modified periodic voltage function. This in turn effects a DC bias on the surface of the substrate that controls an ion energy of ions incident on a surface of the substrate. A peak-to-peak voltage of the periodic voltage function can control the ion energy, while the ion current compensation can control a width of an ion energy distribution function of the ions. Measuring the modified periodic voltage function can provide a means to calculate an ion current in the plasma and a sheath capacitance of the plasma sheath. The ion energy distribution function can be tailored and multiple ion energy peaks can be generated, both via control of the modified periodic voltage function.
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Citations
35 Claims
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1. A method of operating a plasma processing chamber comprising:
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sustaining a plasma in contact with a substrate on a substrate support within the plasma processing chamber; accessing an effective capacitance, C1, of the substrate support; providing a modified periodic voltage function to the substrate support in order to effect a potential on a surface of the substrate, the modified period voltage function formed from a combination of a periodic voltage function and an ion current compensation, IC; and calculating ion current, II, in the plasma as a function of measurements of the modified periodic voltage function. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A plasma processing system comprising:
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a substrate support in a plasma processing chamber supporting a substrate; a substrate support bias supply providing a periodic voltage function; an ion current compensation component providing an ion current compensation that is combined with the periodic voltage function to form a modified periodic voltage function that is provided to the substrate support and thereby effects a DC voltage on a surface of the substrate opposite to the substrate support, which in turn controls an ion energy of ions incident on the surface of the substrate opposite to the substrate support, the modified periodic voltage function having; a first portion comprising a rapidly increasing voltage; a second portion comprising a substantially constant voltage; and a third portion comprising; a sloped voltage having a starting voltage that is a voltage step, Δ
V, below the substantially constant voltage, the voltage step, Δ
V, corresponding to the ion energy, and a slope, dV0/dt, controlled by the ion current compensation; anda controller having a non-transitory, tangible computer readable storage medium encoded with processor readable instructions to; access an effective capacitance of the substrate support, C1; measure the slope, dV0/dt, for at least two ion current compensation values; and calculate ion current, II, as a function of the effective capacitance, C1, and the slope, dV0/dt. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
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28. A non-transitory, tangible computer readable storage medium, encoded with processor readable instructions to perform a method for controlling characteristics of an ion energy distribution function of ions from a plasma that are incident on a substrate within a plasma processing chamber, the method comprising:
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accessing an effective capacitance, C1, of a substrate support supporting the substrate; controlling a periodic voltage function provided by a substrate bias supply and an ion current compensation provided by an ion current compensation component, a combination of the periodic voltage function and the ion current compensation, being a modified periodic voltage function, is provided to the substrate support in order to effect a potential on a surface of the substrate opposite to the substrate support and thereby control an ion energy, eV, of ions incident on the substrate from the plasma; and taking measurements of the modified periodic voltage function; repeatedly calculating an ion current, II, in the plasma based on the measurements. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35)
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Specification