NOVELTY - Deposition of semiconductor material on substrate (400) involves introducing a material and a carrier gas into a first chamber; heating the material such that portion of material vaporizes into a vapor; directing a mixture of vapor and carrier gas through a second chamber to form a uniform vapor/carrier gas composition; and directing the uniform vapor/carrier gas composition proximate to an external heating tube and toward a surface of a substrate having a temperature lower than the vapor.    USE - For depositing a semiconductor material on a substrate used for manufacture of photovoltaic device. The semiconductor material can be cadmium chalcogenide, preferably cadmium sulfide or cadmium telluride (claimed).    ADVANTAGE - Passing the vapor and carrier gas between external heater tubes maintains the vapor in a temperature sufficient to keep the vapor in a vaporized state until the vapor contacts the substrate. This ensures that no powder of semiconductor material is deposited on surface of substrate. Reducing or eliminating the amount of powder from the vapor/carrier gas composition and providing a uniform vapor/carrier gas composition results in a deposited film that is uniform as to both thickness and grain structure, resulting in higher-quality and lower-cost production.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a distributor assembly (300) comprising a first chamber, a heating element providing a temperature high enough that portion of solid material vaporizes into a vapor, a second chamber, an outlet, and an external heating tube; and    (2) a substrate processing system (200) for depositing a film on a substrate comprising a material source connected to a distributor assembly such that a solid material and carrier gas supplied by the material source are introduced into the distributor assembly; and a conveyor for transporting the substrate proximate to the distributor assembly such that the vapor may be deposited on the substrate as a film.    DESCRIPTION OF DRAWING(S) - The figure shows a system for depositing a semiconductor on a glass sheet substrate.    Substrate processing system (200)    Rollers (230)    Housing (240)    Distributor assembly (300)    Substrate (400)