POROUS SUBSTRATE DENSIFICATION METHOD

摘要

A reaction gas phase including methyltrichlorosilane (MTS) and hydrogen is fed into an infiltration chamber (30) in which a substrate is placed under predetermined infiltration pressure and temperature conditions. The gas phase fed into the infiltration chamber is preheated to a suitable temperature by plates (46) before it contacts the substrate. A residual gas phase including a reaction gas phase residue and gaseous reaction products is removed from the chamber. Infiltration is performed at a temperature of 960-1050 DEG C, preferably 1000-1030 DEG C, and at a total pressure no greater than 15 kPa, preferably 7-12 kPa, and the silicon species concentration in the residual gas phase is reduced at the outlet of the infiltration chamber, e.g. by injecting neutral gas (via 70).