Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II. LSA Project. Final report, October 1, 1977-March 31, 1979

Technical Report · Sat Dec 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/5509596· OSTI ID:5509596

Duffy, M T; Berkman, S; Cullen, G W; Aiello, R V; Moss, H I

Amorphous CVD layers of silicon nitride and silicon oxynitride are prepared by chemical vapor deposition (CVD). The CVD layers are converted to ..cap alpha..- and ..beta..-Si/sub 3/N/sub 4/ in contact with molten silicon. Silicon nitride layers are converted initially to ..cap alpha..-Si/sub 3/N/sub 4/ with a low ..beta..-Si/sub 3/N/sub 4/ content. The ..cap alpha.. phase is then slowly converted to the ..beta.. phase accompanied by simultaneous decomposition. By contrast, silicon oxynitride (SiO/sub x/N/sub y/) layers are converted predominantly to ..beta..-Si/sub 3/N/sub 4/ with a low ..cap alpha..-Si/sub 3/N/sub 4/ content. In this process, oxygen is evolved, and there is no evidence for the existence of an oxynitride phase in the resulting layers. The analysis also indicates that ..beta..-Si/sub 3/N/sub 4/ is much more resistant to chemical attack by molten silicon than ..cap alpha..-Si/sub 3/N/sub 4/. Consequently, CVD silicon oxynitride provides a useful means of obtaining relatively pure and inert ..beta..-Si/sub 3/N/sub 4/ as a substrate coating for prolonged exposure to molten silicon, while CVD silicon nitride coatings are useful for shorter exposure times. Crystallographic analysis of silicon ribbon test specimens, grown from CVD-coated vitreous carbon dies, indicates that silicon carbide inclusions are not present in the ribbon samples. The results of infrared analysis also show that the carbon content of the silicon ribbons is below detection level and lower than in the Czochralski seed material.

• Research Organization: RCA Labs., Princeton, NJ (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: NAS-7-100-954901
• OSTI ID: 5509596
• Report Number(s): DOE/JPL/954901-79/6
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140501* -- Solar Energy Conversion-- Photovoltaic Conversion
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
CARBIDES
CARBON
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL ANALYSIS
COATINGS
COST
CRUCIBLES
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
CRYSTALLOGRAPHY
DIES
DIRECT ENERGY CONVERTERS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
EMISSION SPECTROSCOPY
EQUIPMENT
IMPURITIES
INCLUSIONS
INVERTED STEPANOV METHOD
MATERIALS
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PERFORMANCE
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
PNICTIDES
SEMIMETALS
SILICON
SILICON CARBIDES
SILICON COMPOUNDS
SILICON NITRIDES
SILICON OXIDES
SILICON SOLAR CELLS
SINTERED MATERIALS
SOLAR CELLS
SOLAR EQUIPMENT
SPECTROSCOPY
VAPOR DEPOSITED COATINGS