Ceiling electrode plate and substrate processing apparatus
In a plasma processing apparatus, a ceiling electrode plate provided to face a substrate holding stage via a process space contacts and is supported by an electrode support by interposing a cooling plate, and a heat-transfer sheet is provided in a contact surface between the ceiling electrode plate and the cooling plate. The heat-transfer sheet has thermal conductivity of 0.5 to 2.0 W/m·K. The heat-transfer sheet is provided of a heat-resistant adhesive agent or a rubber including silicon, or the heat-transfer sheet is formed of a ceramic filler including oxide, nitride, or carbide. The ceramic filler of 25 to 60 volume % is contained in the heat-resistant adhesive agent or the rubber. A thickness of the heat-transfer sheet is in a range between 30 and 80 μm, and the heat-transfer sheet is not provided in a predetermined area around gas holes of the ceiling electrode plate.
1. A ceiling electrode plate which is supported to be suspended from an electrode support including a temperature adjusting mechanism,
wherein a cooling plate is provided between the ceiling electrode plate and the electrode support, the ceiling electrode plate having a plurality of first gas holes and the cooling plate having a plurality of second gas holes;
a first heat-transfer sheet is coated on a contact surface of the ceiling electrode plate which is located between the ceiling electrode plate and the cooling plate by using a masking material to provide a plurality of openings corresponding to the first gas holes for the first heat-transfer sheet, the first heat-transfer sheet forming a single unitary heat-transfer sheet, wherein the first heat-transfer sheet is not coated on a predetermined area around each of the first gas holes, and wherein the opening, each first gas hole and each second gas hole are communicated with one another to provide a labyrinth-shaped space; and
a parting agent is coated on a contact surface of the cooling plate which is located between the cooling plate and the first heat-transfer sheet.
2. The ceiling electrode plate of claim 1 , wherein the first heat-transfer sheet is not coated on a circular area having a radius of 1.5 mm to 2.5 mm centering around the first gas holes.
3. The ceiling electrode plate of claim 1 , wherein a thickness of the first heat-transfer sheet is equal to or less than 100 μm.
4. The ceiling electrode plate of claim 3 , wherein the thickness of the first heat-transfer sheet is in a range between 30 and 80 μm.
5. The ceiling electrode plate of claim 3 , wherein the ceiling electrode plate is provided to face a substrate holding stage via a process space, wherein the thickness of the first heat-transfer sheet is different at a position facing a center portion of the substrate holding stage and at a position facing a peripheral portion of the substrate holding stage.
6. The ceiling electrode plate of claim 1 , wherein a second heat-transfer sheet is further provided between the electrode support and the cooling plate.
7. The ceiling electrode plate of claim 1 , wherein thermal conductivity of the first heat-transfer sheet is in a range between 0.5 and 2.0 W/m·K.
8. A substrate processing apparatus which comprises a ceiling electrode plate and a substrate holding stage provided to face the ceiling electrode plate via a process space and performs a predetermined process on a substrate placed on the substrate holding stage, wherein the substrate processing apparatus comprises the ceiling electrode plate of claim 1 .