Establishment of the feasibility of a process capable of low-cost, high-volume production of silane (Step I) and the pyrolysis of silane to semiconductor-grade silicon (Step II). Low Cost Silicon Solar Array Project, Silicon Materials Task. Quarterly progress report, July--September 1977

Technical Report · Sun Jan 01 00:00:00 EST 1978

DOI:https://doi.org/10.2172/5100763· OSTI ID:5100763

Breneman, W C; Farrier, E G; Rexer, J

Silane produced via the redistribution of dichlorosilane and purified by distillation followed by adsorption of residual chlorosilane on activated carbon yields 50 ohm-cm silicon on epitaxial deposition. Extended operation of a small process-development unit routinely produced high-quality silane in 97+% yield from dichlorosilane. The production rate was consistent with design loadings for the fractionating column and for the redistribution reactor. Laboratory and process-development reactor systems were built to study the hydrogenation of co-product silicon tetrachloride. An integrated unit for converting hydrogen and silicon to silane is also under construction. A glass fluid-bed reactor was constructed for room-temperature operation. The behavior of a bed of silicon particles was observed as a function of various feedstocks, component configurations, and operating conditions. For operating modes other than spouting, the bed behaved in an erratic and unstable manner. A second reactor with a modified gas-feed system for increased bed stability is being constructed. In some free-space reactor experiments, friable clusters of silicon particles formed on the tip of the gas injector and on the reactor wall. The temperature at the growth sites was the major parameter controlling the extent of these formations. It was also shown that within limits, the particle size of the reactor product can be modified by controlling the temperatures of the reactor and of the injected silane. A method was developed for casting molten silicon powder into crack-free solid pellets for process evaluation. The silicon powder was melted and cast into thin-walled quartz tubes that sacrificially broke on cooling. The samples are intended for resistance and spark-source mass spectroscopic analysis.

• Research Organization: Union Carbide Corp., Sistersville, W.Va. (USA)
• DOE Contract Number: NAS-7-100-954334
• OSTI ID: 5100763
• Report Number(s): DOE/JPL/954334-77/4
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
SILANES
CHEMICAL PREPARATION
PRODUCTION
SILICON
ADSORPTION
CASTING
CHEMICAL REACTORS
EPITAXY
FLUIDIZED BED
PELLETS
POWDERS
SILICON SOLAR CELLS
DIRECT ENERGY CONVERTERS
ELEMENTS
FABRICATION
HYDRIDES
HYDROGEN COMPOUNDS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
SEMIMETALS
SILICON COMPOUNDS
SOLAR CELLS
SORPTION
SYNTHESIS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture