Plasma Deposition of Amorphous Semiconductors at Microwave Frequencies

Apparatus and method for plasma deposition of thin film photovoltaic materials at microwave frequencies. The apparatus avoids deposition on windows that couple microwave energy to deposition species. The apparatus includes a microwave applicator with one or more conduits that carry deposition species. The applicator transfers microwave energy to the deposition species to energize them to a reactive state. The conduits physically isolate deposition species that would react or otherwise combine to form a thin film material at the point of microwave power transfer and deliver the microwave-excited species to a deposition chamber. Supplemental material streams may be delivered to the deposition chamber without passing through the microwave applicator and may combine with deposition species exiting the conduits to form a thin film material. Precursors for the microwave-excited deposition species include fluorinated forms of silicon. Precursors for supplemental material streams include hydrogenated forms of silicon.