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.