MAKING OF TWO-LAYER RESIST IMAGE

摘要

A method of producing a resist image comprising: (a) providing a substrate with a layer of a wet developable resist material as a bottom resist layer and with a layer of a wet developable resist material as a top resist layer, wherein (i) the sensitivity to radiation of the resist material of the top resist layer differs significantly from the sensitivity to radiation of the resist material of the bottom resist layer, and (ii) the resist material of the top resist layer contains sites capable of reacting with a silylating agent; (b) imagewise exposing to radiation the top resist layer, the imagewise exposing of the top resist layer being such that the bottom resist layer is substantially unaffected by said imagewise exposing; (c) wet developing the top resist layer to produce a top layer image; (d) reacting the developed top resist layer with a silylating agent to produce an etch resistant pattern of the top resist layer on the bottom resist layer and also to render the top resist layer resistant to the development to be used for subsequent development of the bottom resist layer; (e) exposing the bottom resist layer through the top layer resist image to radiation capable of rendering the resist material of the bottom resist layer in the exposed areas developable; and (f) developing the exposed bottom resist layer to uncover the substrate in the imagewise exposed and developed areas.