Composite electrode for plasma processes
AssigneeLam Research Corporation
InventorsRaymond L. Degner, Eric H. Lenz
Life of this patent
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Abstract
An electrode assembly for a plasma reactor, such as a plasma etch or plasma-enhanced chemical vapor deposition reactor, comprises an electrode plate having a support frame attached to one surface thereof. The electrode plate is composed of a substantially pure material which is compatible with a particular reaction being performed in the reactor, while the support frame is composed of a material having desirable thermal, electrical, and structural characteristics. The support frame is bonded to the electrode plate using a bonding layer, usually a ductile metallic bonding layer, which provides effective thermal and electrical coupling while permitting a degree of thermal expansion mismatch between the support frame and the electrode plate.
Claims36
An improved reactor of the type having a first electrode for supporting a substrate, an opposed electrode, and means for producing a plasma therebetween, wherein the opposed electrode has one face exposed to the first electrode and an opposite face connected to an electrical source and a thermal sink, the improvement comprising an opposed electrode including (a) an electrode plate composed of a substantially pure material and having a substantially uniform thickness and (b) a support frame composed of an electrically and thermally conductive material bonded to a back face of the plate, whereby the support frame is connected to the electrical source and thermal sink and a front face of the plate which is exposed to the first electrode is substantially free from protuberances.
An electrode assembly comprising:
- an electrode composed of a substantially pure material and having a substantially uniform thickness;
- and
- a support ring bonded about the periphery of one face of the disk, leaving the other face substantially flat and free from protuberances, wherein the support ring is composed of an electrically and thermally conductive material
A method for forming an electrode assembly including a support ring and an electrode plate, said method comprising:
- bonding the support ring about the periphery of the electrode plate at elevated temperature, wherein the material of the electrode plate has a higher coefficient of thermal expansion than that of the electrode plate;
- and
- allowing the bonded assembly to return to room temperature, whereby the differential contraction imparts the desired stress.
Dependencies are inferred from the claim text.