Method and apparatus for improved baffle plate
An apparatus related to plasma chambers used for processing semiconductor substrates and specifically to improvements in pumping baffle plates used in plasma sources. An apparatus and method for making a baffle plate assembly formed from a modified baffle plate blank wherein a variety of pumping features are formed in the baffle plate blank and opened in a planar material removal operation.
1. A method of fabricating a baffle plate assembly, surrounding a substrate holder in a plasma processing system comprising:
providing a plate having a surface and a thickness;
forming a baffle plate blank from the plate by forming multiple variations in a direction perpendicular to the surface of the plate, the multiple variations having a depth in the direction perpendicular to the surface of the plate greater than the thickness of the plate; and
modifying in a single operation by planar material removal at least some of the multiple variations of said baffle plate blank to create one or more pumping passageways.
2. A method according to claim 1 wherein said forming of said baffle plate blank includes metal casting, metal stamping, machining, ceramic fabrication, molding, or quartz fabrication, or any combination thereof.
3. A method according to claim 1 , wherein said planar material removal modification to said blank baffle plate blank comprises milling, grinding, lapping, sanding, planing, or etching, or any combination thereof.
4. A method according to claim 1 , wherein the forming of the baffle plate blank includes forming the baffle plate blank from a plate made from aluminum, alumina, silicon, quartz, carbon, silicon nitride, silicon carbide, or ceramic, or any combination thereof.
5. A method according to claim 1 , further comprising forming a protective barrier on a surface of said baffle plate assembly.
6. A method according to claim 1 , further comprising forming a protective barrier on a portion of a surface of said baffle plate assembly.
7. A method according to claim 5 or 6 , wherein the forming of said protective barrier comprises forming the protective barrier by surface anodization, by coating using plasma electrolytic oxidation, or by spray coating, or any combination thereof.
8. A method according to claim 5 or 6 , wherein the forming of said protective barrier comprises forming a layer of one or more III-column elements or one or more Lanthanon elements, or any combination thereof.
9. A method according to claim 8 , wherein said one or more III-column elements comprise Yttrium, Scandium, or Lanthanum, or any combination thereof.
10. A method according to claim 8 , wherein said one or more Lanthanon elements comprise Cerium, Dysprosium, or Europium, or any combination thereof.
11. A method according to claim 5 or 6 , wherein the forming of said protective barrier comprises forming Al 2 O 3 , Yttria (Y 2 O 3 ), Sc 2 O 3 , Sc 2 F 3 , YF 3 , La 2 O 3 , CeO 2 , Eu 2 O 3 , or DyO 3 , or any combination thereof.
12. A method according to claim 1 , wherein the modifying includes creating one or more of said pumping passages comprising a slot, or an orifice, or any combination thereof.
13. A method according to claim 12 , wherein the modifying includes creating an orifice having a shape and design of a round hole, a polygon, an icon, one or more letters of any language, or any open geometric shape.
14. A method according to claim 1 , wherein the modifying to create the one or more pumping passageways includes creating pumping passageways with a variable size, shape or distribution, or any combination thereof, on said baffle plate assembly.
15. A method according to claim 1 , wherein the forming of the baffle plate blank from the plate includes forming a baffle plate blank having no holes in the vicinity of the multiple variations of said baffle plate blank.
16. A method according to claim 1 , wherein the forming of the baffle plate blank from the plate includes forming variations in the plate without creating openings in the plate.