Optics for controlling light transmitted through a conical quartz dome
Embodiments described herein generally relate to apparatus for heating substrates. The apparatus generally include a process chamber having a substrate support therein. A plurality of lamps is positioned to provide radiant energy through an optically transparent dome to a substrate positioned on the substrate support. A light focusing assembly is positioned within the chamber to influence heating and temperature distribution on the substrate and to facilitate formation of a film on a substrate having uniform properties, such as density. The light focusing assembly can include one or more reflectors, light pipes, or refractive lenses.
1. A process chamber, comprising:
a chamber body including an optically transparent dome;
a substrate support disposed within the chamber body;
a plurality of lamps disposed adjacent to the optically transparent dome; and
a light focusing assembly positioned within the chamber body between the plurality of lamps and a substrate positioned on the substrate support, the light focusing assembly adapted to influence radiant energy emitted from the plurality of lamps, wherein:
the light focusing assembly comprises a plurality of concentric rings or polygonal approximations to rings, the concentric rings or the polygonal approximations to rings comprising quartz; and
the concentric rings or the polygonal approximations to rings contain a hollow cavity therein, and interior walls of the hollow cavity having a reflective coating thereon.
2. The process chamber of claim 1 , wherein at least some of the concentric rings have different heights.
3. The process chamber of claim 1 , wherein the reflective coating comprises silver, gold, or aluminum.
4. The process chamber of claim 1 , wherein the concentric rings each have a thickness within a range of about 2.5 millimeters to about 35 millimeters.
5. The process chamber of claim 1 , wherein a support shaft coupled to the substrate support is disposed through a center of an innermost ring of the plurality of concentric rings.
6. The process chamber or claim 5 , wherein the support shaft is formed form quartz and contains a hollow cavity therein.
7. The process chamber of claim 1 , wherein the light focusing assembly further comprises a plurality of refractive elements disposed between adjacent concentric rings.
8. The process chamber of claim 7 , wherein the refractive elements include convex or concave lenses.
9. The process chamber of claim 7 , wherein the refractive elements include Fresnel lenses.
10. The process chamber of claim 1 , wherein the lamps are positioned outside of a processing region of the chamber body.
11. A process chamber, comprising:
a chamber body including an optically transparent dome;
a substrate support disposed within the chamber body, the substrate support having a support shaft extending therefrom;
a plurality of lamps disposed adjacent to the optically transparent dome; and
a light focusing assembly positioned within the chamber body between the optically transparent dome and the substrate support, the light focusing assembly in contact with an upper surface of the optically transparent dome and adapted to influence radiant energy emitted from the plurality of lamps wherein:
the light focusing assembly comprises a plurality of concentric rings or polygonal approximations to rings, the concentric rings or the polygonal approximations to rings comprising quartz; and
the concentric rings or the polygonal approximations to rings contain a hollow cavity therein, and interior walls of the hollow cavity having a reflective coating thereon.
12. The process chamber of claim 11 , wherein the support shaft includes a hollow cavity therein.
13. The process chamber of claim 12 , wherein the light focusing assembly further comprises a plurality of refractive elements disposed between adjacent concentric rings.
14. The process chamber of claim 13 , wherein the refractive element comprises a concave, convex, or Fresnel lenses.