SYSTEMS AND METHODS FOR LOW-OXYGEN CRYSTAL GROWTH USING A DOUBLE-LAYER CONTINUOUS CZOCHRALSKI PROCESS

• Main Author: Kimbel, Steven Lawrence
• Format: Patent
• Language: English
• Published: 06.12.2018
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; CHEMISTRY; CRYSTAL GROWTH; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A method and system for double-layer continuous Cz crystal growing are disclosed. The system includes a crucible assembly including an inner crucible in an outer crucible, the inner crucible defining a growth region and a feed region, the crucible assembly containing molten material (e.g., silicon). The system also includes a susceptor, a continuous feed supply for providing a continuous feed to the feed region, and a temperature control system disposed about the susceptor and configured to cool a region of silicon at a bottom of the growth region to form a solid layer, the solid layer facilitating reducing an oxygen concentration in the growing crystal. The method includes separating molten material into the growth region and the feed region, initiating cooling at a bottom of the growth region, and solidifying a region of material at the bottom of the growth region, such that a solid layer is formed.