Abstract: A pattern forming method providing a satisfactory pattern shape of high resolution power and high sensitivity. A pattern forming material comprising a resin containing hydroxyl groups is coated on a substrate and selectively exposed by Deep UV light using an optional mask. Then, the surface of the unexposed area is selectively silylated by hexamethyl disilazane and, thereafter dry-developed by reactive ion etching using O.sub.2 gas. With such a constitution, the exposed area and the unexposed area can be distinguished clearly to obtain a resist pattern of high resolution power. Further, since the Deep UV light has a property of being strongly absorbed to the resist film, the sensitivity is increased. Further, since the Deep UV light does not reach as far as the lower portion of the resist film, no undesirable notching phenomenon occurs even if there is any step on the substrate to be fabricated.

Abstract: A method of forming patterns for providing satisfactory pattern shapes of high resolution and high sensitivity is disclosed. A resin film comprising hydroxyl groups is formed on a substrate. Deep UV light selectively irradiates the resin film using a desired mask under nitrogen atmospherre. The surface of the non-exposed portion is selectively silylated by hexamethyldisilazane followed by dry development using reactive ion etching comprising O.sub.2 gas. In accordance with this method, photo irradiation is carried out under inert gas atmosphere so that crosslinking reaction of the resin film proceeds significantly, with the hydroxyl groups concentration greatly reduced. As a result, there is selectivity in silylation reaction between the exposed portion and the non-exposed portion. The exposed portion and the non-exposed portion is precisely distinguished by dry development. Accordingly, resist patterns of high resolution can be obtained.