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 a material including a powder and a carrier gas into a first chamber including an interior, wherein the first chamber is tubular and comprises:
a heating element positioned within the interior of the first chamber and heated by resistive heating to a temperature high enough that at least a portion of the powder vaporizes into a vapor;
a first flow path through which a mixture of vapor and carrier gas is directed to form a substantially uniform vapor/carrier gas composition; and
a plurality of distribution holes;
passing the vapor through at least one of the plurality of distribution holes in the first chamber into a second chamber, wherein the first chamber is permeable to the vapor but impermeable to the powder, and wherein the second chamber is tubular and is positioned outside the first chamber so that the second tubular chamber sheaths at least a portion of the first tubular chamber to form a second flow path through which the mixture of vapor and carrier gas is directed to maintain the substantially uniform vapor/carrier gas composition; and
directing the substantially uniform vapor/carrier gas composition through the plurality of distribution holes and toward a surface of a substrate proximate to the second chamber and having a temperature lower than the vapor.
2. The method of claim 1 , wherein the material is a cadmium chalcogenide.
3. The method of claim 2 , wherein the cadmium chalcogenide is cadmium telluride or cadmium sulfide.
4. The method of claim 1 , wherein the heating element maintains a temperature of at least 500 degrees C.
5. The method of claim 4 , wherein the heating element maintains a temperature of about 500 degrees C. to about 700 degrees C.
6. The method of claim 1 , further comprising providing a mixture of vapor and carrier gas having substantially no solid material after at least a portion of the material vaporizes into a vapor.