Tunable focus ring for plasma processing
OwnerWayne L. Johnsoninventor
Life of this patent
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Abstract
A focus ring (200) and related assembly for a plasma reactor system (100, 400) for processing a workpiece (176) having an outer edge and an upper surface. The assembly has a focus ring support surface (173) arranged around the workpiece perimeter and a ring electrode (210) arranged atop the focus ring support surface. An insulating focus ring (200) is arranged atop the ring electrode. In one embodiment, a first RF power supply (180) is electrically connected to the focus ring electrode and a tuning network (220) is arranged between the first RF power supply and the ring electrode. Methods of forming a plasma (130) and processing a workpiece in an optimized way, as well as a plasma reactor system for accomplishing the same, are also disclosed.
Claims21
A focus ring assembly apparatus for a plasma reactor system for processing a workpiece having an outer edge and an upper surface, comprising:
- a) a ring electrode;
- b) a focus ring made of nonconductive material arranged atop, and insulated from, said ring electrode;
- c) a first RF power supply electrically connected to said focus ring electrode;
- and
- d) a tuning network arranged between said first RF power supply and said ring electrode.
A focus ring assembly apparatus for a plasma reactor system for processing a workpiece having an outer edge and an upper surface, comprising:
- a) a focus ring support surface arranged around the workpiece outer edge,
- wherein said focus ring support surface is part of a workpiece support member having a lower electrode capable of supporting the workpiece, a base surrounding said lower electrode, and an insulating region between said lower electrode and said base, wherein said focus ring support surface is part of said base;
- b) a ring electrode arranged atop said focus ring support surface;
- c) a focus ring made of nonconductive material arranged atop said ring electrode;
- d) a first RF power supply electrically connected to said focus ring electrode;
- and
- e) a second RF power supply electrically connected to said lower electrode.
A method of plasma processing a workpiece to a desired standard, the workpiece having an upper surface and an outer edge with a reactor system having a reactor chamber containing a focus ring arranged adjacent the workpiece outer edge and made of a material M and having a profile P, inner and outer radii (RI and RO), the ring being positioned a vertical distance D from the workpiece upper surface, wherein a ring electrode is arranged adjacent the focus ring, the system thus having a set A of variable process parameters {P, R, M, D}, the method comprising the steps of:
- a) setting parameters A={P, R, M, D} to initial values;
- and
- b) processing one or more workpieces while varying one or more of said process parameters to determine an optimized set of process parameters A*={P*, R*, M*, D*} that provide the desired processing to within a predetermined standard.
Dependencies are inferred from the claim text.