A process of realizing a silicon micropattern having a large aspect ratio in a semiconductor-manufacturing process, and a novel wet etching method that includes treating an organic carbon film layer so that a hydrofluoric-acid-resistant material is selectively attached to the organic carbon film layer and then wet etching the same using an aqueous solution containing hydrofluoric acid, thus forming a pattern, are proposed. In the method of forming the pattern by wet etching, etching is performed so that an active region having a depth of several μm in an object to be etched is not damaged when a pattern having a small CD is formed, thereby exhibiting an effect of providing a method of forming a micropattern.