Processes for the purification of trichlorosilane or silicon tetrachloride
AssigneeMEMC Electronic Materials, Inc.
InventorGianfranco Ghetti
Life of this patent
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Abstract
The present disclosure relates to processes and systems for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride.
Claims12
A process for purifying technical grade trichlorosilane or technical grade silicon tetrachloride into electronic grade trichlorosilane or electronic grade silicon tetrachloride, the process comprising:
- adding diphenylthiocarbazone or triphenylchloromethane to the technical grade trichlorosilane or technical grade silicon tetrachloride to form complex impurity macromolecules with impurities in the technical grade trichlorosilane or technical grade silicon tetrachloride, the impurities being selected from the group consisting of boron impurities, metallic impurities, and combinations thereof;
- distilling the technical grade trichlorosilane or technical grade silicon tetrachloride having complex impurity macromolecules in a first column distillation, wherein the first column distillation results in first distillation tops and first distillation bottoms, wherein the first distillation bottoms comprise complex impurity macromolecules separated from the first distillation tops;
- and
- distilling the first distillation tops in a second column distillation resulting in second distillation tops and second distillation bottoms, wherein the second distillation bottoms comprise a residual amount of trichlorosilane or silicon tetrachloride and a compound selected from the group consisting of phosphorus containing compounds, arsenic containing compounds, aluminum compounds, antimony compounds, carbosilane compounds, and combinations thereof, and the second distillation tops comprise electronic grade trichlorosilane or electronic grade silicon tetrachloride.
A process for purifying technical grade trichlorosilane or technical grade silicon tetrachloride into electronic grade trichlorosilane or electronic grade silicon tetrachloride, the process comprising:
- adding diphenylthiocarbazone or triphenylchloromethane to the technical grade trichlorosilane or technical grade silicon tetrachloride to form complex impurity macromolecules with impurities in the technical grade trichlorosilane or technical grade silicon tetrachloride, the impurities being selected from the group consisting of boron impurities, metallic impurities, and combinations thereof;
- distilling the technical grade trichlorosilane or technical grade silicon tetrachloride having complex impurity macromolecules in a first column distillation, wherein the first column distillation results in first distillation tops and first distillation bottoms, wherein the first distillation bottoms comprise complex impurity macromolecules separated from the first distillation tops;
- and
- distilling the first distillation tops in a second column distillation resulting in second distillation tops and second distillation bottoms, wherein the second distillation bottoms comprise a residual amount of trichlorosilane or silicon tetrachloride and a metalloid compound, and the second distillation tops comprise electronic grade trichlorosilane or electronic grade silicon tetrachloride.
Dependencies are inferred from the claim text.