LSA large area silicon sheet task continuous liquid feed Czochralski growth. Quarterly report No. 5, October-December 1978
Research on the design and development of equipment and processes, to demonstrate continuous growth of crystals by the Czochralsi method, suitable for producing single silicon crystals for use in solar cells is described. Continuous growth is defined as the growth of 100 Kg of single silicon crystal, 10 cm in diameter, from one container. Siltec's approach to meeting this goal is to develop a furnace with continuous liquid replenishment of the growth crucible, accomplished by a melt-down system and a liquid transfer mechanism, with associated automatic feedback controls. Elements of the transfer system were further developed and tested during actual transfer runs. Considerable simplification of the heating element of the transfer tube was achieved. Accuracy and reliability of the temperature sensor, which is part of the power input control system for the transfer tube, was improved. Following the schedule of the growth demonstration plan, melt-down and transfer of molten silicon from the melt-down crucible into the growth crucible containing molten silicon was performed successfully, verifying the melt-down and transfer operation (rate of silicon transfer > 2 Kg/hr). The final task of the growth demonstration plan prior to attempting 100 Kg throughput runs was achieved. This included the demonstration of continuous melt replenishment of the growth crucible while growing a crystal of 100 mm diameter and maintaining a constant melt level in the growth crucible. Crystals grown from a melt with continuous liquid replenishment exhibited a very small or zero longitudinal resistivity gradient when the ratio of the dopant concentrations of the replenishing melt to the melt in the growth crucible was equal to the effective segregation coefficient of the used dopant.
- Research Organization:
- Siltec Corp., Menlo Park, CA (USA)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- NAS-7-100-954886
- OSTI ID:
- 5767130
- Report Number(s):
- DOE/JPL/954886-5
- Country of Publication:
- United States
- Language:
- English
Similar Records
LSA large area silicon sheet task continuous liquid feed Czochralski growth. Quarterly report No. 6, January-March 1979
Continuous liquid feed Czochralski growth. LSSA Large Area Silicon Sheet Task. Quarterly report No. 3, April--June 1978
Related Subjects
36 MATERIALS SCIENCE
SILICON
CRYSTAL GROWTH
CONTROL SYSTEMS
CRUCIBLES
CZOCHRALSKI METHOD
ELECTRIC CONDUCTIVITY
EQUIPMENT
FURNACES
MONOCRYSTALS
RESEARCH PROGRAMS
SILICON SOLAR CELLS
TEMPERATURE MEASUREMENT
CRYSTALS
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELEMENTS
PHOTOELECTRIC CELLS
PHOTOVOLTAIC CELLS
PHYSICAL PROPERTIES
SEMIMETALS
SOLAR CELLS
140501* - Solar Energy Conversion- Photovoltaic Conversion
360601 - Other Materials- Preparation & Manufacture