Method of joining components for a composite showerhead electrode assembly for a plasma processing apparatus
AssigneeLam Research Corporation
InventorRajinder Dhindsa
Life of this patent
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Abstract
A showerhead electrode for a plasma processing apparatus includes an interface gel between facing surfaces of an electrode plate and a backing plate. The interface gel maintains thermal conductivity during lateral displacements generated during temperature cycling due to mismatch in coefficients of thermal expansion. The interface gel comprises, for example, a silicone based composite filled with aluminum oxide microspheres. The interface gel can conform to irregularly shaped features and maximize surface contact area between mating surfaces. The interface gel can be pre-applied to a consumable upper electrode.
Claims15
A method of joining components for a composite showerhead electrode assembly for a plasma processing apparatus, comprising:
- applying an interface gel to a top surface of an electrode plate in a predetermined pattern within bridging regions, the electrode plate having a plasma exposed bottom surface and a plurality of gas passages extending between the top surface and the bottom surface and having inlets in unbridged regions;
- aligning a bottom surface of a backing plate with the top surface of the electrode plate, the backing plate having a top surface and a plurality of gas passages extending between the top surface and the bottom surface having outlets in unbridged regions;
- and
- attaching the top surface of the electrode plate to the bottom surface of the backing plate with a clamp or adhesive bond, wherein the interface gel is spread laterally into bridging regions between the top surface of the electrode plate and the bottom surface of the backing plate without bonding the electrode plate to the backing plate and the interface gel remains a gel and the gas passages of the backing plate are in fluid communication with the gas passages of the electrode plate.
A method of joining components for a composite showerhead electrode assembly for a plasma processing apparatus, comprising:
- applying an interface gel to a top surface of an electrode plate in a predetermined pattern within bridging regions, the electrode plate having a plasma exposed bottom surface and a plurality of gas passages extending between the top surface and the bottom surface and having inlets in unbridged regions;
- aligning a bottom surface of a backing plate with the top surface of the electrode plate, the backing plate having a top surface and a plurality of gas passages extending between the top surface and the bottom surface having outlets in unbridged regions;
- attaching the top surface of the electrode plate to the bottom surface of the backing plate with a clamp or adhesive bond, wherein the interface gel is spread laterally into bridging regions between the top surface of the electrode plate and the bottom surface of the backing plate and the gas passages of the backing plate are in fluid communication with the gas passages of the electrode plate;
- and
- pressing the backing plate to the electrode plate with the interface gel therebetween in an alignment fixture.
A method of joining components for a composite showerhead electrode assembly for a plasma processing apparatus, comprising:
- applying an interface gel to a top surface of an electrode plate in a predetermined pattern within bridging regions, the electrode plate having a plasma exposed bottom surface and a plurality of gas passages extending between the top surface and the bottom surface and having inlets in unbridged regions;
- aligning a bottom surface of a backing plate with the top surface of the electrode plate, the backing plate having a top surface and a plurality of gas passages extending between the top surface and the bottom surface having outlets in unbridged regions;
- attaching the top surface of the electrode plate to the bottom surface of the backing plate with a clamp or adhesive bond, wherein the interface gel is spread laterally into bridging regions between the top surface of the electrode plate and the bottom surface of the backing plate and the gas passages of the backing plate are in fluid communication with the gas passages of the electrode plate;
- and
- (a) the attaching further comprises seating the interface gel in the bridging regions by pressing the top surface of the electrode plate and the bottom surface of the backing plate together under compression, under a static weight or optionally by atmospheric pressure within a vacuum bag;
- (b) the electrode plate is of silicon, graphite, or silicon carbide;
- and the backing plate is of aluminum, graphite, or silicon carbide;
- (c) applying the interface gel to the top surface of the electrode plate comprises using a transfer sheet;
- (d) applying the bottom surface of the backing plate to the interface gel comprises removing the transfer sheet from the interface gel before applying the bottom surface of the backing plate;
- and/or
- (e) the electrode plate comprises an inner showerhead electrode and an outer ring electrode and the backing plate comprises a circular inner backing plate and an outer backing ring and the interface gel is disposed in the bridging regions between the inner showerhead electrode and the inner backing plate and/or the outer ring electrode and the outer backing ring.
Dependencies are inferred from the claim text.