Patent ID: 7854820

Claim:
A component for a plasma processing apparatus for processing semiconductor substrates, the component comprising: a first member having a plurality of first through openings, the first member having a plasma-exposed surface and a first coefficient of thermal expansion, the first openings located at different radial positions across the surface; a second member bonded with an elastomeric bonding material to the first member and having a plurality of second through openings corresponding to the first openings, the second member having a second coefficient of thermal expansion greater than the first coefficient of thermal expansion; wherein the second openings are larger than the first openings and centers of the first and second openings are misaligned at ambient temperature and the centers of the first and second openings move radially and are closer together due to thermal expansion when the first and second members are heated to a predetermined elevated processing temperature; wherein: (a) the openings in the first member and the openings in the second member are substantially concentric when the first and second members are heated to the predetermined elevated processing temperature; (b) the second openings reduce the exposure of the second member to a plasma environment; (c) the second openings are non-circular; (d) the second openings are semi-elliptical holes or radially elongated slots; (e) the openings in the first and second members are axially extending gas distribution passages; (f) the second member is composed of a metal; (g) the second member is composed of aluminum, molybdenum, copper, stainless steel, or alloys thereof; or (h) the first member is composed of a non-metallic material.