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US 8,641,820 B2Granted
Crystal manufacturing
AssigneeOkmetic Oyj
InventorsOlli Anttila, Ari Saarnikko, Jari Paloheimo
Life of this patent
Estimating the term…
Abstract
An implementation of a Czochralski-type crystal growth has been shown and embodied. More particularly, a furnace with suitable insulation and flow arrangement is shown to improve the cost-efficiency of production of crystals. That is achieved by the shown new hot-zone structure, gas flows and the growth process which can decrease the power consumption, increase the lifetime of hot-zone parts and improve the productivity, e.g., by giving means for opening the hot-zone and easily adapting the hot-zone to a new crystal diameter.
Claims2
A method for a Czochralski crystal growth, wherein said method comprises
- dividing an inlet flow in a hot zone of a furnace so that a first partial flow is guided through a melt region of the hot zone, which comprises a region above or inside a crucible of the hot zone, and a second partial flow is prevented to interact with a shielding member of the hot zone and said first partial flow in said region above the crucible and inside the crucible for improving a quality of a crystal, wherein said method further comprises
- feeding a gas flow for an atmosphere to a growth chamber, dividing an input gas flow to the growth chamber into the first partial flow and the second partial flow, leading an incident part of said first partial flow towards a melt surface for forming a secondary part of said first partial flow by means of a guiding surface, insulating said incident and secondary parts of said first partial flow from each other for maintaining a temperature of the secondary part of the first partial flow at or close to a melt temperature, and leading said first partial flow to exit the hot zone and the second partial flow to avoid a melt in the crucible and/or a crystal-pulling region, as a sheath gas flow to an exit.
Dependencies are inferred from the claim text.