skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Floating Silicon Method

Abstract

The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.

Authors:
Publication Date:
Research Org.:
Applied Materials-Varian Semiconductor Equipment
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1126212
Report Number(s):
DOE-FSM-00595
DOE Contract Number:
EE0000595
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 14 SOLAR ENERGY; Floating Silicon Method, FSM

Citation Formats

Kellerman, Peter. Floating Silicon Method. United States: N. p., 2013. Web. doi:10.2172/1126212.
Kellerman, Peter. Floating Silicon Method. United States. doi:10.2172/1126212.
Kellerman, Peter. Sat . "Floating Silicon Method". United States. doi:10.2172/1126212. https://www.osti.gov/servlets/purl/1126212.
@article{osti_1126212,
title = {Floating Silicon Method},
author = {Kellerman, Peter},
abstractNote = {The Floating Silicon Method (FSM) project at Applied Materials (formerly Varian Semiconductor Equipment Associates), has been funded, in part, by the DOE under a “Photovoltaic Supply Chain and Cross Cutting Technologies” grant (number DE-EE0000595) for the past four years. The original intent of the project was to develop the FSM process from concept to a commercially viable tool. This new manufacturing equipment would support the photovoltaic industry in following ways: eliminate kerf losses and the consumable costs associated with wafer sawing, allow optimal photovoltaic efficiency by producing high-quality silicon sheets, reduce the cost of assembling photovoltaic modules by creating large-area silicon cells which are free of micro-cracks, and would be a drop-in replacement in existing high efficiency cell production process thereby allowing rapid fan-out into the industry.},
doi = {10.2172/1126212},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sat Dec 21 00:00:00 EST 2013},
month = {Sat Dec 21 00:00:00 EST 2013}
}

Technical Report:

Save / Share:
  • The Seeded Growth Furnace was completed and operated extensively during the third quarter. Optimum thermal geometry, gas flows, and withdrawal rates are being determined. Surface growth was obtained having growth velocity as high as 5 to 6 mm/min. The surface growth has generally taken the form of interlocking crystals and is thin enough to follow the liquid surface. Its thickness has been determined in one case to be 20 microns. A molybdenum susceptor has been made for the seeded growth furnace. It is anticipated that this new design will eliminate the problems caused by films on the melt and seedmore » crystal and lead to improved crystal structure in the silicon growth. A series of experiments were performed in order to determine whether the reactor gas streams were sources of contamination. Nitrogen reacts with silicon at 1100/sup 0/C to coat its surface with a film 30 to 150A thick. Silicon heated in hydrogen at temperatures between 1000 and 1200/sup 0/C maintains a very clean, film-free surface.« less
  • The work described was directed toward the demonstration of the practical feasibility of the Floating Substrate Process for the growth of silicon sheet. Supercooling of silicon--tin alloy melts was studied. Values as high as 78/sup 0/C at 1100/sup 0/C and 39/sup 0/C at 1200/sup 0/C were observed, corresponding to supersaturation parameter values 0.025 and 0.053 at 1050/sup 0/C and 1150/sup 0/C, respectively. The interaction of tin with silane gas streams was investigated over the temperature range 1000 to 1200/sup 0/C. Single-pass conversion efficiencies exceeding 30% were obtained. The growth habit of spontaneously-nucleated surface growth was determined to be consistent withmore » dendritic and web growth from <111> singly-twinned triangular nucleii. Surface growth of interlocking silicon crystals, thin enough to follow the surface of the liquid and with growth velocity as high as 5 mm/min, was obtained. Large area single-crystal growth along the melt surface was not achieved. Small single-crystal surface growth was obtained which did not propagate beyond a few millimeters. The probable reason for the polycrystalline growth is the poisoning of the growth interface by impurities.« less
  • The floating-zone method for the growth of Group IVB and VB carbides is described and reviewed. We have systematically investigated the technique and confirmed the growth of large single crystals of TiC/sub 0.95/, ZrC/sub 0.93/, ZrC/sub 0.98/, VC/sub 0.80/, NbC/sub 0.95/, TaC/sub 0.89/. Optimal growth conditions were in the 0.5-2.0 cm/h range under 8-12 atm helium. Good crystal growth results were achieved with hot-pressed starting rods of 90-95% density, using a ''double pancake'' induction coil and a 200-kHz/100- kW rf power supply. 36 refs., 5 figs., 3 tabs.