Gas distribution plate assembly for plasma reactors
View Patent ↗A baffle plate assembly for distributing gas flows into an adjacent process chamber containing a semiconductor wafer to be processed includes a planar gas distribution portion having a plurality of apertures therein; a flange surrounding the gas distribution portion; and an impingement device centrally attached to the gas distribution portion, wherein the device includes a cap and a stem, the stem being in thermal contact with the gas distribution portion. Also disclosed herein are plasma reactors employing the baffle plate assembly and methods for reducing recombination of species in a plasma.
1. A baffle plate assembly for distributing gas flows into an adjacent process chamber containing a semiconductor wafer to be processed, comprising:
a single generally circular planar gas distribution portion having a plurality of apertures therein;
a flange surrounding the gas distribution portion; and
an apertureless impingement device centrally attached to the gas distribution portion, wherein the device includes a generally circular cap and a stem, the stem being in thermal contact with the gas distribution portion.
2. The baffle plate assembly of claim 1 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from aluminum.
3. The baffle plate assembly of claim 1 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from quartz.
4. The baffle plate assembly of claim 1 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from sapphire coated quartz.
5. The baffle plate assembly of claim 1 , wherein the cap has a planar impingement surface.
6. The baffle plate assembly of claim 1 , wherein the cap has an angled impingement surface.
7. The baffle plate assembly of claim 1 , wherein the cap has a substantially triangular cross sectional shape.
8. The baffle plate assembly of claim 1 , wherein the cap has a concave surface.
9. The baffle plate assembly of claim 1 , wherein the cap has a convex surface.
10. The baffle plate assembly of claim 1 ,wherein the plurality of apertures of the gas distribution portion have a frustoconical portion extending from a top surface to about a midpoint of the gas distribution portion, wherein the frustoconical portion has a first diameter at the top surface that narrows to a second diameter at about the midpoint and a substantially straight portion extending from the midpoint to a bottom surface of the gas distribution portion, wherein the substantially straight portion has the second diameter.
11. The baffle plate assembly of claim 1 , wherein the gas distribution portion further comprises cooling passages machined therein for circulating a cooling medium therethrough.
12. The baffle plate assembly of claim 1 , wherein the cap has a diameter about equal to a diameter of an opening for receiving plasma into a process chamber in which the baffle plate assembly is disposed.
13. A downstream plasma asher comprising:
a plasma generator;
a process chamber downstream from the plasma generator, the process chamber comprising an opening for receiving plasma from the plasma generator into the process chamber, and a substrate supported within the process chamber; and
a baffle plate assembly intermediate the substrate and the process chamber opening for distributing plasma flow in the process chamber, the baffle plate assembly comprising a single generally circular planar gas distribution portion having a plurality of apertures therein; a flange surrounding the gas distribution portion; and an apertureless impingement device centrally attached to the gas distribution portion, wherein the device includes a generally circular cap and a stem, the cap having a diameter about equal to a diameter of the process chamber opening and the stem in thermal contact with the gas distribution portion.
14. The downstream plasma asher of claim 13 , wherein the plasma generator is a selected from the group consisting of microwave plasma generator, a radiofrequency plasma generator, or a combination thereof.
15. The downstream plasma asher of claim 13 , wherein the impingement device is removable.
16. The downstream plasma asher of claim 13 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from aluminum.
17. The downstream plasma asher of claim 13 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from quartz.
18. The downstream plasma asher of claim 13 , wherein the gas distribution portion, the flange, and the impingement device are fabricated from sapphire coated quartz.
19. The downstream plasma asher of claim 13 , wherein the cap has a planar impingement surface.
20. The downstream plasma asher of claim 13 , wherein the cap has an angled impingement surface.
21. The downstream plasma asher of claim 13 , wherein the cap has a substantially triangular cross sectional shape.
22. The downstream plasma asher of claim 13 , wherein the cap has a concave surface.
23. The downstream plasma asher of claim 13 , wherein the cap has a convex surface.
24. The downstream plasma asher of claim 13 , wherein the plurality of apertures of the gas distribution portion have a frustoconical portion extending from a top surface to about a midpoint of the gas distribution portion, wherein the frustoconical portion has a first diameter at the top surface that narrows to a second diameter at about the midpoint, and a substantially straight portion extending from about the midpoint to a bottom surface of the gas distribution portion, wherein the substantially straight portion has the second diameter.
25. The downstream plasma asher of claim 13 , wherein the gas distribution portion further comprises cooling passages machined therein for circulating a cooling medium therethrough.
26. The downstream plasma asher of claim 13 , wherein a diameter of the gas distribution portion is about equal to a diameter of the substrate.