Process and system for the purification of trichlorosilane and silicon tetrachloride

A process for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride, the process comprising:

• adding diphenylthiocarbazone and/or triphenylchloromethane to the technical grade trichlorosilane and/or technical grade silicon tetrachloride to form complex impurity macromolecules with impurities in the technical grade trichlorosilane and/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 and/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;
• 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 and/or silicon tetrachloride and a compound selected from the group consisting of phosphorus containing compounds, arsenic containing compounds, aluminum compounds, antimony compounds, metalloid compounds, carbosilane compounds, and combinations thereof, and the second distillation tops comprise electronic grade trichlorosilane and/or electronic grade silicon tetrachloride;
• and
• distilling the second distillation bottoms into third distillation tops and third distillation bottoms in a third column distillation, the third distillation bottoms comprising a compound selected from the group consisting of phosphorus containing compounds, arsenic containing compounds, aluminum compounds, antimony compounds, metalloid compounds, carbosilane compounds, and combinations thereof, and the third distillation tops comprising silicon tetrachloride and/or trichlorosilane free of dichlorosilane.

A process for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride, the process comprising:

• adding diphenylthiocarbazone and/or triphenylchloromethane to the technical grade trichlorosilane and/or technical grade silicon tetrachloride to form complex impurity macromolecules with impurities in the technical grade trichlorosilane and/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 and/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, the first column distillation initially operating with a total reflux of the first distillation such that the impurities completely form complex impurity macromolecules, the initial total reflux of the first distillation tops being carried out for at least 3 hours;
• 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 and/or silicon tetrachloride and a compound selected from the group consisting of phosphorus containing compounds, arsenic containing compounds, aluminum compounds, antimony compounds, metalloid compounds, carbosilane compounds, and combinations thereof, and the second distillation tops comprise electronic grade trichlorosilane and/or electronic grade silicon tetrachloride.