Circular lamp arrays
Embodiments disclosed herein relate to circular lamp arrays for use in a semiconductor processing chamber. Circular lamp arrays utilizing one or more torroidal lamps disposed in a reflective trough and arranged in a concentric circular pattern may provide for improved rapid thermal processing. The reflective troughs, which may house the torroidal lamps, may be disposed at various angles relative to a surface of a substrate being processed.
1. A lamphead apparatus, comprising:
a conical body having a bottom surface, the conical body comprising a plurality of reflective troughs formed therein, the plurality of reflective troughs consisting of:
a first reflective trough formed in the conical body, wherein a focal axis of the first reflective trough is angled toward an outer edge of the body at an angle relative to an axis normal to the bottom surface;
a second reflective trough formed in the conical body, the second reflective trough disposed radially inward of the first reflective trough; and
a third reflective trough formed in the conical body, the third reflective trough disposed radially outward of the first reflective trough.
2. The lamphead apparatus of claim 1 , wherein each of the reflective troughs has a semi-circular cross-section, parabolic cross-section, truncated parabolic cross-section, or a combination thereof.
3. The lamphead apparatus of claim 1 , wherein the focal axis of the first reflective trough is angled between about 5° and about 25° from the axis normal to the bottom surface.
4. The lamphead apparatus of claim 1 , wherein the first reflective trough has a radius of curvature between about 110 mm and about 150 mm.
5. The lamphead apparatus of claim 1 , wherein a curved linear lamp is disposed at least partially within the first reflective trough at an angle which is similar to the focal axis of the first reflective trough.
6. A lamphead apparatus, comprising:
a body having a bottom surface, the body having a plurality of reflective troughs formed therein, the plurality of reflective troughs consisting of three reflective troughs, the three reflective troughs comprising:
a first reflective trough formed in the body, the first reflective trough having a first focal axis at a first angle relative to an axis normal to the bottom surface, wherein the first focal axis is angled toward a center of the body;
a second reflective trough formed in the body radially outward of and adjacent to the first reflective trough, the second reflective trough having a second focal axis at a second angle relative to the axis normal to the bottom surface, wherein the second focal axis is angled toward an outer edge of the body; and
a third reflective trough disposed radially outward from the second reflective trough.
7. The lamphead apparatus of claim 6 , wherein the body is flat or conical.
8. The lamphead apparatus of claim 6 , wherein the first angle is between about 5° and about 25°.
9. The lamphead apparatus of claim 8 , wherein the second angle is between about 5° and about 25°.
10. The lamphead apparatus of claim 6 , wherein the first reflective trough has a radius of curvature between about 50 mm and about 90 mm.
11. The lamphead apparatus of claim 10 , wherein the second reflective trough has a radius of curvature between about 110 mm and about 150 mm.
12. A lamphead apparatus, comprising:
a body having a bottom surface defining a plane, the body having a plurality of reflective troughs formed therein, the plurality of reflective troughs consisting of:
a first reflective trough formed in the body, the first reflective trough having a first focal axis at a first angle relative to an axis normal to the plane defined by the bottom surface, wherein the first focal axis is angled toward a center of the body;
a second reflective trough formed in the body and adjacent to the first reflective trough, the second reflective trough having a second focal axis at a second angle relative to the axis normal to the plane defined by the bottom surface, wherein the second focal axis is angled toward an outer edge of the body; and
a third reflective trough formed in the body and adjacent to the second trough, the third reflective trough having a third focal axis parallel to the axis normal to the plane defined by the bottom surface.
13. The lamphead apparatus of claim 12 , wherein the first angle is between about 5° and about 25°.
14. The lamphead apparatus of claim 13 , wherein the second angle is between about 5° and about 25°.
15. The lamphead apparatus of claim 12 , wherein the first reflective trough has a radius of curvature that is about 72 mm, the second reflective trough has a radius of curvature that is about 131 mm, and the third reflective trough has a radius of curvature that is about 190 mm.
16. The lamphead apparatus of claim 12 , wherein a single torroidal lamp is disposed within each of the reflective troughs or a plurality of bulbs are disposed within each of the reflective troughs.