Paper TF+PS-ThM10
High Deposition Rate and Uniformity of Silicon Thin Films Deposited Via Efficient, Low-Damage Surface Wave Plasma Source

Thursday, October 31, 2013, 11:00 am, Room 102 C

An innovative surface wave plasma source provided by Starfire Industries, LLC has been tested by the Center for Plasma-Material Interactions at the University of Illinois Urbana-Champaign. Operating in the microwave range, the source efficiently generates high-density (10^11~12 cm^-3) and low electron temperature (~1 eV) plasmas. Thin silicon films were deposited with the interest of characterizing a cost-effective PECVD process for high quality silicon photovoltaics. Parameters of interest included substrate temperature, total operating pressure, silane dilution, RF power, discharge gap width, and process gas flowrate. Through a SiH₄:H₂ discharge, films were deposited and subsequently analyzed via profilometry, SEM, Raman microscopy, and X-ray diffraction. For a 15 cm source, consistent radial uniformity was maintained across a 12 cm diameter from 2.0±0.4 nm/s up to 3.5±0.9 nm/s at a 2.5 cm discharge gap. Well-formed films were produced with substrate temperatures above 285C. With decreasing operating pressure and increasing flowrate, area of coverage is shown to increase without compromising speed of film growth. An assessment on deposition rate optimization, film uniformity, and large-area scalability is presented.