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Title: Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II: LSSA project. Quarterly report No. 4

Abstract

The results of emission spectroscopic analysis indicate that molten silicon (sessile drop) can remain in contact with hot-pressed Si/sub 3/N/sub 4/ (99.2% theoretical density) for prolonged periods without attaining the impurity content level of the nitride. It is interesting to note that, although MgO was used as binder (approx. 3.8%), Mg was not found present in the silicon sessile drop in quantities much above the level initially present in the silicon source material. The conversion of CVD silicon oxynitride to ..beta..-Si/sub 3/N/sub 4/ can be carried out at high temperature in N/sub 2/ (approx. 1600/sup 0/C), by contact with molten silicon or by a combination of these steps. Conversion in the presence of molten silicon appears preferable. Preliminary experiments with EFG-type dies coated with CVD Si/sub 3/N/sub 4/ or CVD SiO/sub x/N/sub y/ indicate that capillary rise does not occur readily in these dies. The same was found to be true of hot-pressed and reaction-sintered Si/sub 3/N/sub 4/ obtained commercially. However, when dies were formed by depositing CVD layers on shaped silicon slabs, a column of molten silicon (approx. 2.5 cm high) was maintained in each CVD die while being heated (approx. 30 min) in contact with a crucible ofmore » molten silicon. Preliminary wetting of dies appears necessary for EFG growth. Several ribbon growth experiments were performed in our new ribbon growth facility from V-shaped dies. Both CVD Si/sub 3/N/sub 4/ and CVD SiO/sub x/N/sub y/ coatings were used on the die parts. There is also a problem with the wetting of SiO/sub x/N/sub y/ in the inverted ribbon growth process but not with Si/sub 3/N/sub 4/ layers. After about 90 min in contact with the melt, however, silicon flows into the defining slot in the case of SiO/sub x/N/sub y/ coatings.« less

Authors:
; ; ;
Publication Date:
Research Org.:
RCA Labs., Princeton, NJ (USA)
Sponsoring Org.:
USDOE
OSTI Identifier:
6081575
Report Number(s):
DOE/JPL/954901-4
DOE Contract Number:  
NAS-7-100-954901
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; DIES; MATERIALS; VAPOR DEPOSITED COATINGS; SILICON; CRYSTAL GROWTH; BINDERS; CAPILLARY FLOW; CRUCIBLES; IMPURITIES; REFRACTORIES; RESEARCH PROGRAMS; SILICON NITRIDES; SUBSTRATES; COATINGS; ELEMENTS; FLUID FLOW; NITRIDES; NITROGEN COMPOUNDS; PNICTIDES; SEMIMETALS; SILICON COMPOUNDS; 140501* - Solar Energy Conversion- Photovoltaic Conversion; 360601 - Other Materials- Preparation & Manufacture

Citation Formats

Duffy, M T, Berkman, S, Moss, H I, and Cullen, G W. Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II: LSSA project. Quarterly report No. 4. United States: N. p., 1978. Web. doi:10.2172/6081575.
Duffy, M T, Berkman, S, Moss, H I, & Cullen, G W. Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II: LSSA project. Quarterly report No. 4. United States. https://doi.org/10.2172/6081575
Duffy, M T, Berkman, S, Moss, H I, and Cullen, G W. 1978. "Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II: LSSA project. Quarterly report No. 4". United States. https://doi.org/10.2172/6081575. https://www.osti.gov/servlets/purl/6081575.
@article{osti_6081575,
title = {Development and evaluation of die materials for use in the growth of silicon ribbons by the inverted ribbon growth process. Task II: LSSA project. Quarterly report No. 4},
author = {Duffy, M T and Berkman, S and Moss, H I and Cullen, G W},
abstractNote = {The results of emission spectroscopic analysis indicate that molten silicon (sessile drop) can remain in contact with hot-pressed Si/sub 3/N/sub 4/ (99.2% theoretical density) for prolonged periods without attaining the impurity content level of the nitride. It is interesting to note that, although MgO was used as binder (approx. 3.8%), Mg was not found present in the silicon sessile drop in quantities much above the level initially present in the silicon source material. The conversion of CVD silicon oxynitride to ..beta..-Si/sub 3/N/sub 4/ can be carried out at high temperature in N/sub 2/ (approx. 1600/sup 0/C), by contact with molten silicon or by a combination of these steps. Conversion in the presence of molten silicon appears preferable. Preliminary experiments with EFG-type dies coated with CVD Si/sub 3/N/sub 4/ or CVD SiO/sub x/N/sub y/ indicate that capillary rise does not occur readily in these dies. The same was found to be true of hot-pressed and reaction-sintered Si/sub 3/N/sub 4/ obtained commercially. However, when dies were formed by depositing CVD layers on shaped silicon slabs, a column of molten silicon (approx. 2.5 cm high) was maintained in each CVD die while being heated (approx. 30 min) in contact with a crucible of molten silicon. Preliminary wetting of dies appears necessary for EFG growth. Several ribbon growth experiments were performed in our new ribbon growth facility from V-shaped dies. Both CVD Si/sub 3/N/sub 4/ and CVD SiO/sub x/N/sub y/ coatings were used on the die parts. There is also a problem with the wetting of SiO/sub x/N/sub y/ in the inverted ribbon growth process but not with Si/sub 3/N/sub 4/ layers. After about 90 min in contact with the melt, however, silicon flows into the defining slot in the case of SiO/sub x/N/sub y/ coatings.},
doi = {10.2172/6081575},
url = {https://www.osti.gov/biblio/6081575}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1978},
month = {9}
}