Quartz glass crucible and method for treating surface of quartz glass crucible
View Patent ↗There is provided a quartz glass article having a surface treated with novel coating materials which provides a reduced chemistry, wherein the quartz glass surface having a reduced chemistry upon exposure to melted silicon or similarly corrosive environments, forms crystalline structures covering at least 30% of the coated surface of the quartz glass crucible. Said crystalline covered surface provides a more stable surface of contact with the silicon melt and the growth of single crystal silicon. In one embodiment of the invention, the coating material comprises at least a methyl group for providing at least one of a hydrogenated and a methylated surface on the coated surface, forming rosette structures, or other crystalline morphologies covering at last 80% of the coated surface. In another embodiment of the invention, the coating material is selected from at least one of an amine, an organosilane halogen and mixtures thereof.
1. A quartz glass article in the form of a crucible for growing single silicon crystal in a Czochralski operation, comprising:
a surface having coated thereon a coating material effecting a reduced chemistry on the coated surface, the coating material comprising at least one of a halogermane, a halostannate, an alkyl halo germane, an alkyl halo stannate, a substituted germane, an alkyl stannate, an alkoxy stannate, a Lewis acid, and mixtures thereof;
the glass article containing at least 99.0% SiO 2 , wherein upon exposure to a meltdown and crystal pulling process cycle, the reduced chemical species react to form a plurality of rosettes and/or other crystalline morphology structures, covering at least 30% of the coated surface of the quartz glass crucible.
2. The quartz glass article of claim 1 , wherein the coating material is dissolved in a solvent selected from the group of alkanes, halogenated alkanes, alcohols, and mixtures thereof prior to being applied onto the surface of the crucible.
3. The quartz glass article of claim 1 , wherein the coating material comprises at least one of: a halogen hydrogen silane, a metallic halogen Lewis acid, an alkyl halosilane, and mixtures thereof.
4. The quartz glass article of claim 1 , wherein the coating material comprises a Lewis acid selected from the group of: an alkyl magnesium halide; an aryl magnesium halide; an alkyl calcium halide; an alkyl strontium halide; and alkyl barium halide; a boron trifluoride; a ferric chloride; and an aluminum trichloride.
5. The quartz glass article of claim 1 , wherein the coating material comprises at least a Lewis acid for providing at least one of a hydrogenated group and a metal for bonding to the coated surface of the crucible, modifying the coated surface chemistry.
6. The quartz glass article of claim 1 , wherein the coating material comprises one of a halogen germane, an alkoxide of germane, an alkyl of germane, and an organogermane halogen.
7. The quartz glass article of claim 6 , wherein the coating material comprises a least one of trialkylchlorogermane; dialkyldichlorogermane, alkyltrichlorogermane and dialkyldihalogengermane.
8. The quartz glass article of claim 6 , wherein the coating material comprises a least one of an (alkyl) 2 GeCl 2 , an (alkyl) 2 GeBr 2 , an (alkyl) 2 GeF 2 , and an (aryl) 2 GeCl 2 , and mixtures thereof.
9. The quartz glass article of claim 6 , wherein the coating material comprises at least one of an Ge(alkoxy)4, an (alkyl)Ge(alkoxy) 3 , an (alkyl) 2 Ge(alkoxy) 2 an (alkyl) 3 Ge(alkoxy), and mixtures thereof.
10. A process for preparing at least a surface of a quartz glass crucible of claim 1 , for exposure to a silicon melt in growing single silicon crystal in a Czochralski operation, the process comprising: coating at least 75% of the surface to be exposed to the silicon melt with a material comprising at least one of a substituted germane, an alkyl stannate, an alkoxy stannate, a Lewis acid, and mixtures thereof, wherein the coating material provides at least one of a hydrogenated group and a metal for bonding to the coated surface of the crucible and the modified surface of the quartz crucible nucleates and forms crystalline structures covering at least 30% of the coated surface of the quartz glass crucible.
11. The process of claim 10 , further comprising the steps of: dissolving the coating material in a solvent selected from the group of alkanes, halogenated alkanes, alcohols, and mixtures thereof; coating the surface of the crucible by applying the dissolved coating material on the crucible surface to be exposed to the silicon melt.