| The direct synthesis of methylchlorosilanes are studied on semiconductor-grade Si(100) and Si(111) surfaces in a recirculating batch reactor at atmospheric pressure and 598 K. The surfaces were characterized by Auger electron spectroscopy (AES) and ellipsometry before deposition of catalysts. After reaction with methyl chloride (CH;High purity Si(100) readily reacts in the presence of copper catalysts to form dimethyldichlorosilane, methyltrichlorosilane, and trimethylchlorosilane, and thus the Si(100) surface is an excellent model for silicon powders that are reacted in fluidized bed reactors. The form of copper is a critical factor, however, in obtaining good selectivities and rates on these high purity silicon surfaces. Copper catalysts physically placed on the silicon surfaces as mixtures of Cu and Cu;Reacted surfaces were found to have square pits etched into the surface. A correlation was not found, however, between the amount of Cu;Copper(II) formate dihydrate catalyst readily decomposed on silicon surfaces to form a Cu/Cu;This work was funded by Elkem Metals Company. |
