Showerhead assembly
A method and apparatus for removing native oxides from a substrate surface is provided. In one embodiment, the apparatus for removing native oxides from a substrate surface includes a showerhead assembly. One embodiment of a showerhead assembly includes a hollow cylinder, a disc and an annular mounting flange. The hollow cylinder has a top wall, a bottom wall, an inner diameter wall and an outer diameter wall. The disc has a top surface and a lower surface. The top surface is coupled to the inner diameter wall. The lower surface is coupled to the bottom wall. The disc has a plurality of apertures connecting the lower surface to the top surface. The annular mounting flange extends from the outer diameter wall of the hollow cylinder. The mounting flange has an upper surface and a lower surface. The upper surface is coplanar with the top wall of the hollow cylinder. The lower surface having an elevation above the top surface of the disc. In another embodiment, a resistive heater is embedded in the hollow cylinder proximate the disc.
1. A processing chamber comprising a showerhead including a grounded electrode having a recess in its top center to hold a top electrode through an isolator ring; wherein the top electrode has a passage formed there through with a gradually increasing inner diameter; wherein the improvement comprises:
a hollow cylinder having a top wall, a bottom wall, an inner diameter wall and an outer diameter wall;
a disc having a top surface and a lower surface, the top surface coupled to the inner diameter wall, the lower surface coupled to the bottom wall, the disc having a plurality of apertures connecting the lower surface to the top surface;
an annular mounting flange extending from the outer diameter wall of the hollow cylinder, the mounting flange having an upper surface and a lower surface, the upper surface coplanar with the top wall of the hollow cylinder, the lower surface having an elevation above the top surface of the disc, wherein the hollow cylinder, the disc and the annular mounting flange are formed as a one piece structure; and
a channel circumscribing and positioned coplanar with the disc
the said annular mounting flange supporting the grounded electrode, wherein the plurality of apertures of the disk are in fluid communication with the passage of the top electrode.
2. The showerhead assembly of claim 1 further comprising:
an o-ring type seal gland formed in the annular mounting flange.
3. The showerhead assembly of claim 1 , wherein the heater is positioned below the lower surface of the mounting flange.
4. The showerhead assembly of claim 1 further comprising:
a thermocouple positioned in the showerhead assembly.
5. The showerhead assembly of claim 1 , wherein the disc and the annular mounting flange are fabricated from an aluminum alloy.
6. The showerhead assembly of claim 1 , wherein the disc and the annular mounting flange have a thermal resistance of less than about 5×10 −4 m 2 K/W.
7. A processing chamber comprising a showerhead including a grounded electrode having a recess in its top center to hold a top electrode through an isolator ring; wherein the top electrode has a passage formed there through with a gradually increasing inner diameter; wherein the improvement comprises:
a hollow cylinder having a top wall, a bottom wall, an inner diameter wall and an outer diameter wall;
a disc having a top surface and a lower surface, the top surface coupled to the inner diameter wall, the lower surface coupled to the bottom wall, the disc having a plurality of apertures connecting the lower surface to the top surface, the inner diameter wall and the top surface defining a recessed center surface;
an annular mounting flange extending from the outer diameter wall of the hollow cylinder, the mounting flange having an upper surface and a lower surface, the upper surface coplanar with the top wall of the hollow cylinder, the lower surface having an elevation above the top surface of the disc, wherein the hollow cylinder, the disc and the annular mounting flange are formed as a one piece structure; and
a channel circumscribing the recessed center surface and positioned coplanar with the disc
the said annular mounting flange supporting the grounded electrode, wherein the plurality of apertures of the disk are in fluid communication with the passage of the top electrode.
8. The showerhead assembly of claim 7 , wherein the disc, hollow cylinder and the annular mounting flange are fabricated from an aluminum alloy.
9. The showerhead assembly of claim 7 , wherein the disc and the annular mounting flange have a thermal resistance of less than about 5×10 −4 m 2 K/W.
10. The showerhead assembly of claim 7 , wherein the heater is positioned in the passage.
11. The showerhead assembly of claim 10 further comprising:
a thermocouple disposed in the showerhead assembly.