Spike anneal residence time reduction in rapid thermal processing chambers
The present invention generally relates to methods of cooling a substrate during rapid thermal processing. The methods generally include positioning a substrate in a chamber and applying heat to the substrate. After the temperature of the substrate is increased to a desired temperature, the substrate is rapidly cooled. Rapid cooling of the substrate is facilitated by increasing a flow rate of a gas through the chamber. Rapid cooling of the substrate is further facilitated by positioning the substrate in close proximity to a cooling plate. The cooling plate removes heat from substrate via conduction facilitated by gas located therebetween. The distance between the cooling plate and the substrate can be adjusted to create a turbulent gas flow therebetween, which further facilitates removal of heat from the substrate. After the substrate is sufficiently cooled, the substrate is removed from the chamber.
1. A method of processing a substrate, comprising:
positioning a substrate on a substrate support within a chamber, the substrate positioned a first distance from a cooling plate within the chamber;
applying heat to a substrate to increase a temperature of the substrate to a predetermined temperature, wherein a process gas is provided to the chamber while applying heat to the substrate;
ceasing the application of heat after the substrate has reached the predetermined temperature;
increasing a flow rate of the process gas provided to and removed from the chamber;
positioning the substrate a second distance from the cooling plate, wherein the second distance is less than the first distance;
decreasing the temperature of the substrate; and
removing the substrate from chamber.
2. The method of claim 1 , wherein ceasing the application of heat occurs substantially concurrently with increasing the flow rate of the process gas.
3. The method of claim 2 , wherein the positioning the substrate a second distance from the cooling plate occurs substantially concurrently with ceasing the application of heat and increasing the flow rate of the process gas.
4. The method of claim 1 , wherein the increasing a flow rate of the process gas provided to and removed from the chamber is facilitated by use of a high speed electric valve.
5. The method of claim 1 , wherein the increasing a flow rate of the process gas provided to and removed from the chamber comprises increasing the flow rate five-fold or more.
6. The method of claim 1 , wherein the second distance is within a range of about 100 microns to about 200 microns.
7. The method of claim 1 , wherein an edge ring is disposed around a periphery of the substrate, and wherein the edge ring has an internal diameter greater than the diameter of the cooling plate.
8. The method of claim 1 , wherein the process gas has a turbulent flow during the decreasing the temperature of the substrate.
9. The method of claim 1 , wherein the process gas comprises nitrogen, helium, or argon.
10. The method of claim 1 , wherein the process gas flows parallel to an upper surface of the substrate.
11. A method of processing a substrate, comprising:
positioning a substrate on a substrate support within a chamber, the substrate positioned a first distance from a cooling plate within the chamber;
applying heat to a substrate using a plurality of lamps to increase a temperature of the substrate to a predetermined temperature, wherein a process gas comprising nitrogen, argon, or helium is provided to the chamber while applying heat to the substrate;
ceasing the application of heat after the substrate has reached the predetermined temperature;
increasing a flow rate of the process gas provided to and removed from the chamber using a high speed electric valve;
positioning the substrate a second distance from the cooling plate, wherein the second distance is less than the first distance;
decreasing the temperature of the substrate; and
removing the substrate from chamber.
12. The method of claim 11 , wherein the process gas is provided to the chamber through openings disposed within the cooling plate.
13. The method of claim 11 , wherein the process gas flows parallel to an upper surface of the substrate.
14. The method of claim 11 , wherein decreasing the temperature of the substrate comprises decreasing the temperature of the substrate about 50 degrees Celsius in about 0.6 seconds or less.
15. The method of claim 11 , wherein an edge ring is disposed around the circumference of the substrate, and wherein the edge ring has an upper surface positioned above an upper surface of the substrate.
16. The method of claim 11 , wherein an edge ring is disposed around the circumference of the substrate, and wherein the edge ring has an upper surface positioned below an upper surface of the substrate.
17. The method of claim 11 , wherein the second distance is within a range of about 100 microns to about 200 microns.
18. The method of claim 11 , wherein the cooling plate has a coolant flowing therethrough.
19. The method of claim 11 , wherein the process gas is introduced into the chamber in a direction perpendicular to an upper surface of the substrate.
20. A method of processing a substrate, comprising:
positioning a substrate on a substrate support within a chamber, the substrate having an edge ring disposed therearound;
applying heat to a substrate using a plurality of lamps to increase a temperature of the substrate to a predetermined temperature greater than about 600 degrees Celsius, wherein a process gas comprising nitrogen, argon, or helium is provided to the chamber while applying heat to the substrate;
ceasing the application of heat after the substrate has reached the predetermined temperature;
increasing a flow rate of the process gas provided to and removed from the chamber using a high speed electric valve;
positioning the substrate about 100 microns to about 200 microns from a cooling plate;
decreasing the temperature of the substrate; and
removing the substrate from chamber.