Abstract: A system and method whereby the uniformity of the silylating agent throughout the reaction chamber and primarily at the surface of the wafer is significantly improved to provide a significant improvement in the line width uniformity. In accordance with a first embodiment of the invention, this is accomplished by stagnant silylation wherein the silylating agent is introduced into the reaction chamber and the reaction chamber is then sealed during the entire time required to carry out the silylation. The advantage of this approach is optimum uniformity since once equilibrium has been reached, there is no net change of flow or pressure of the silylating agent across the wafer. Another advantage is reduction in the total consumption of the silylating and carrier gases. In accordance with a second embodiment of the invention, the silylating agent flows laminarly across the surface of the wafer to provide uniformity of the silylating agent at the wafer surface.