Plasma reactor with overhead RF source power electrode with low loss, low arcing tendency and low contamination
First Claim
1. A gas distribution ceiling electrode, comprising:
- (A) a metal base comprising;
a gas manifold near the top of said base,a plurality of first arcuately slotted gas passages, each passage having a starting end inside said base, each passage extending axially from said starting end to the bottom of said base,a plurality of radially extending pressure-dropping orifices coupled between said gas manifold and the starting ends of said first arcuately slotted gas passages;
(B) a protective layer formed of a process-compatible material at the bottom of said base, and comprising;
a plurality of second arcuately slotted gas passages extending through said protective layer and being in registration with said plurality of first arcuately slotted gas passages;
(C) plural adhesive islands between said metal base and said protective layer.
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Accused Products
Abstract
A gas distribution ceiling electrode for use as a capacitive source power applicator and gas distribution showerhead in a plasma reactor includes a metal base and a process-compatible protective layer on the interior surface of he electrode having a dopant impurity concentration within a range corresponding to a minimal change in RF power absorption in the protective layer at an RF source power frequency with changes in coating temperature and or thickness. The metal base may have a set of first arcuately slotted gas passages and a set of pressure-dropping orifices coinciding axially with the top ends of the gas passages. The protective coating a set of arcuately slotted gas passages in registration gas passages of the metal base. The pressure drop in the orifices and the electric field drop in the slotted gas passages are both sufficient to maintain the pressure and electric field within the gas passages within a range that prevents arcing.
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Citations
54 Claims
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1. A gas distribution ceiling electrode, comprising:
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(A) a metal base comprising; a gas manifold near the top of said base, a plurality of first arcuately slotted gas passages, each passage having a starting end inside said base, each passage extending axially from said starting end to the bottom of said base, a plurality of radially extending pressure-dropping orifices coupled between said gas manifold and the starting ends of said first arcuately slotted gas passages; (B) a protective layer formed of a process-compatible material at the bottom of said base, and comprising; a plurality of second arcuately slotted gas passages extending through said protective layer and being in registration with said plurality of first arcuately slotted gas passages; (C) plural adhesive islands between said metal base and said protective layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
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32. A gas distribution ceiling electrode for use as a capacitive source power applicator and gas distribution showerhead in a plasma reactor, comprising:
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a metal base; a protective layer formed of a process-compatible material at the bottom of said base; said process-compatible material having a dopant impurity concentration within a range corresponding to a minimal change in RF power absorption with respect to a change in at least one of;
(a) temperature of said protective layer, (b) thickness of said protective layer, (c) dopant impurity concentration in said protective layer. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40)
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41. A plasma reactor for processing a semiconductor workpiece, comprising:
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a reactor chamber having a chamber wall and containing a workpiece support for holding the semiconductor workpiece; an overhead electrode overlying said workpiece support; an RF power generator for supplying power at a source power frequency to said overhead electrode, said generator being capable of maintaining a plasma within said chamber at a desired plasma ion density level; said overhead electrode having a reactance that forms a resonance with the plasma at an electrode-plasma resonant frequency which is at or near said source power frequency at said desired plasma ion density level; said overhead electrode comprising; (a) a metal base; (b) a protective layer formed of a process-compatible material at the bottom of said base; (c) said process-compatible material having a dopant impurity concentration within a range corresponding to a minimal change in RF power absorption at said source power frequency with respect to a change in at least one of;
(a) temperature of said protective layer, (b) thickness of said protective layer, (c) dopant impurity concentration in said protective layer.- View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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Specification