Method and apparatus for crystal ribbon growth
OwnerCarl E. Bleilinventor
Life of this patent
Estimating the term…
Abstract
Crystals are grown in ribbon shapes by an apparatus for supporting a film of source material, capacitive electrodes contacting the film and heat pipes in thermal contact with the electrodes for first heating the material through the electrodes to near its melting temperature and then for controllably cooling the electrodes, an rf heater using the electrodes for melting the film in a zone, a heat pipe for causing solidification along one surface of the melt zone to form a ribbon, a pulling mechanism for moving the ribbon from the melt zone, a heater for melting bulk replenishing material to replenish the melt, and an auxiliary heating device for heating the ribbon after leaving the zone to prevent dendritic growth by maintaining low axial temperature gradients.
Claims10
Apparatus for forming a crystalline ribbon from source material comprising:
- means for supporting a film of material in a plane,
- first heating means comprising temperature regulated means in thermally conductive relation to the film for initially heating the material and subsequently stabilizing the temperature surrounding the film,
- second heating means for melting the film of material and maintaining the temperature of the molten film including planar electrodes parallel to the said plane for producing electrical currents in the material causing a film of material to melt along a zone in the source body, wherein at least one of the planar electrodes is in thermally conductive relation with both the first heating means and the film of material to provide a thermal path from the first heating means to the film of material.
- means for controllably removing heat from the molted film of material in a direction substantially perpendicular to the plane to effect ribbon growth,
- means for causing relative motion parallel to the plane between the ribbon and the heating means, and
- means for replenishing the melted film.
Apparatus for forming a crystalline ribbon from source material comprising:
- means for supporting a film of material in a plane,
- first heating means comprising a pair of heat pipes spaced along the film in thermally conductive relation to the film and means for controlling the heat pipes to a temperature just below the melting point of the material for initially heating the material and subsequently stabilizing the temperature surrounding the film,
- second heating means for melting the film of material and maintaining the temperature of the molten film and for conducting heat between the heat pipes and the film including a pair of spaced planar electrodes parallel to the said plane for capacitively coupling radio frequency electrical currents into the material causing a film of material to melt along a zone in the source body, the planar electrodes each including a semiconductive electrode in contact with the film of material, a conductive electrode in thermal contact with a respective heat pipe and a dielectric layer between the conductive and semiconductive electrodes,
- means for controllably removing heat from the melted film of material in a direction substantially perpendicular to the plane to effect ribbon growth,
- means for causing relative motion parallel to the plane between the ribbon and the heating means, and
- means for replenishing the melted film.
Dependencies are inferred from the claim text.