Thermal process chamber lid with backside pumping
Process chamber lid assemblies and process chambers comprising same are described. The lid assembly has a housing with a gas dispersion channel in fluid communication with a lid plate. A contoured bottom surface of the lid plate defines a gap to a top surface of a gas distribution plate. A pumping channel is formed between an upper outer peripheral contour of the gas distribution plate and the lid plate.
1. A process chamber lid assembly, comprising:
a housing enclosing a gas dispersion channel that extends along a central axis of the housing, the gas dispersion channel having an upper portion and a lower portion;
a lid plate coupled to the housing and having a contoured bottom surface that extends downwardly and outwardly from a central opening coupled to the lower portion of the gas dispersion channel to a peripheral portion of the lid plate, the contoured bottom surface of the lid plate comprises an inner zone, a middle zone and an outer zone, the inner zone defined from a central axis of the lid plate to an inner zone radial distance from the central axis, the middle zone defined from the inner zone radial distance to a middle zone radial distance from the central axis, and the outer zone measured from the middle zone radial distance to an outer zone radial distance at an outer peripheral edge of the contoured bottom surface; and
a gas distribution plate disposed below the lid plate, the gas distribution plate having an upper outer peripheral contour configured to form a pumping channel between the gas distribution plate and the lid plate, the gas distribution plate having a top surface and a bottom surface with a plurality of apertures disposed through the gas distribution plate from the top surface to the bottom surface, the contoured bottom surface of the lid plate and top surface of the gas distribution plate defining a gap, the inner zone of the contoured bottom surface of lid having a larger gap than the middle zone of the contoured bottom surface of the lid, the middle zone of the contoured bottom surface of the lid having a larger gap than the outer zone of the contoured bottom surface of the lid, the outer zone is sloped from the middle zone to a front face of the lid plate forming an outer zone angle, the outer zone of the contoured bottom surface is connected to the pumping channel through pumping holes formed in the lid plate.
2. The lid assembly of claim 1 , wherein the middle zone of the contoured bottom surface forms a substantially uniform gap.
3. The lid assembly of claim 2 , wherein the substantially uniform gap is in the range of about 0.1 inch to about 2 inches.
4. The lid assembly of claim 1 , wherein the middle zone comprises in the range of about 10% to about 90% of the distance from the central axis to the outer zone radial distance.
5. The lid assembly of claim 1 , wherein the pumping holes are formed in the outer zone of the contoured bottom surface.
6. The lid assembly of claim 1 , wherein the pumping holes intersect the outer zone of the contoured bottom surface at an angle in the range of about 85° to about 95°.
7. The lid assembly of claim 1 , wherein there are in the range of about 24 to about 144 pumping holes in the outer zone.
8. The lid assembly of claim 1 , further comprising at least one pump port in fluid communication with the pumping channel.
9. A processing chamber comprising the lid assembly of claim 1 .
10. The processing chamber of claim 9 , further comprising a remote plasma source fluidly coupled to the gas dispersion channel.