Method and system for selective recovery of monochlorosilane and dichlorosilane in polysilicon production process
AssigneeAdvanced Material Solutions, LLC
InventorsChad Fero, Kevin Papp, Joah Smith, Joshua Flynn
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Abstract
A method and system for selectively recovering monochlorosilane and dichlorosilane from polysilicon production process are provided. The system and method selectively recover the monochlorosilane and the dichlorosilane contained in an exhaust stream discharged from a chemical vapor deposition unit for a polysilicon production process and the monochlorosilanes and the dichlorosilanes may be obtained with minimal capital investment or complexity.
Claims14
A method for selective recovering monochlorosilane and dichlorosilane in a polysilicon production process, comprising:
- i) discharging an exhaust gas from a chemical vapor deposition reactor for producing polysilicon, wherein the exhaust gas includes hydrogen, silicontetrachloride, trichlorosilane, monochlorosilane and dichlorosilane;
- ii) removing the hydrogen from the exhaust gas in a gas recovery device to produce a hydrogen removed condensate;
- iii) removing the silicon tetrachloride and the trichlorosilane from the hydrogen removed condensate using a set of distillation columns to produce a hydrogen silicon-tetrachloride trichlorosilane removed result;
- and
- iv) selectively recovering an upper stream and lower stream from the hydrogen silicon-tetrachloride trichlorosilane removed result in a selective distillation column, wherein the upper stream comprises monochlorosilane and the lower stream comprises dichlorosilane.
A system for selective recovering monochlorosilane and dichlorosilane in polysilicon production process comprising,
- a chemical vapor deposition reactor to produce polysilicon and discharge an exhaust gas, wherein the exhaust gas comprises hydrogen, silicontetrachloride, trichlorosilane, monochlorosilane and dichlorosilane;
- a gas recovery device to introduce the exhaust gas to separate the hydrogen and to discharge a first stream without hydrogen;
- a set of distillation columns to introduce the first stream to separate the silicontetrachloride and the trichlorosilane and to discharge a second stream;
- and
- a selective distillation column to introduce the second stream and selectively discharge an upper stream and a lower stream respectively, wherein the upper stream comprises monochlorosilane and the lower stream comprises dichlorosilane.
Dependencies are inferred from the claim text.