System and method for depositing a material on a substrate
A method and apparatus for depositing a film on a substrate includes introducing a material and a carrier gas into a heated chamber. The material may be a semiconductor material, such as a cadmium chalcogenide. A resulting mixture of vapor and carrier gas containing no unvaporized material is provided. The mixture of vapor and carrier gas are remixed to achieve a uniform vapor/carrier gas composition, which is directed toward a surface of a substrate, such as a glass substrate, where the vapor is deposited as a uniform film.
1. A method for depositing a material on a substrate, comprising:
introducing the material as a powder and a carrier gas into a first chamber, the first chamber comprising one or more first chamber walls which are permeable to a vapor and the carrier gas but impermeable to the solid material;
heating a heating element associated with the first chamber to a temperature sufficient to vaporize at least a portion of the powder into a vapor;
directing the vapor through the one or more permeable first chamber walls into a second chamber positioned outside the first chamber that provides a material flow sufficiently indirect to mix the vapor and the carrier gas into a substantially uniform vapor/carrier gas composition;
directing the vapor carrier gas composition from the second chamber into a first passageway formed in a block, the first passageway having an inlet and an outlet;
after the vapor carrier gas composition passes through the first passageway outlet, directing the vapor/carrier gas composition from the first passageway outlet towards a portion of an external surface of the second chamber to disperse the vapor/carrier gas composition and further increase its uniformity; and
directing the substantially uniform vapor/carrier gas composition towards a surface of a substrate.
2. The method of claim 1 , wherein at least one of the first and second chambers are tubular.
3. The method of claim 2 , wherein the second chamber comprises a second chamber outlet, the second chamber outlet connecting the second chamber and the first passageway.
4. The method of claim 3 , wherein the second chamber outlet comprises a single hole.
5. The method of claim 1 , wherein the material is selected from the group consisting of cadmium chalcogenide, cadmium telluride, and cadmium sulfide.
6. The method of claim 1 , wherein the step of heating the heating element comprises heating the first chamber to a temperature of at least 500 degrees C.
7. The method of claim 6 , wherein the step of heating the heating element comprises heating the first chamber to a temperature of at least 700 degrees C.
8. The method of claim 1 , wherein the heating element is incorporated into the first chamber.
9. The method of claim 3 , wherein the first passageway comprises a first passageway outlet including between about 10 to about 50 distribution holes.
10. The method of claim 9 , wherein the distribution holes are co-linear to the second chamber outlet.
11. The method of claim 1 , wherein the surface of the substrate has a lower temperature than the vapor.
12. The method of claim 1 , further comprising directing the vapor/carrier gas composition towards a portion of an external surface of the block before directing the substantially uniform vapor/carrier gas composition towards a surface of the substrate.