Method for forming fine patterns in a semiconductor device

Abstract

A method for forming a fine pattern, e.g., for forming the storage electrodes of the capacitors of the memory cells of semiconductor memory devices, which includes the steps of depositing a mask layer on the layer to be patterned, depositing a photoresist layer on the mask layer, patterning the photoresist layer, to thereby form a photoresist pattern, anisotropically etching the mask layer, using the photoresist pattern as an etching mask, to thereby form a mask layer pattern, wherein etch by-products are formed on sidewalls of a composite layer comprised of the photoresist pattern and the mask layer pattern, and, etching the layer to be patterned using the composite layer and the etch by-products as an etching mask, to thereby form a fine pattern. The mask layer is made of a material, e.g., a high-temperature oxide, having different physical properties than that of the photoresist. Further, the anisotropic etching process is preferably carried out by means of a plasma etching process using a mixture of CF.sub.4, CHF.sub.4, and Ar gases, with the amount of the etch by-products being controllably adjusted by the ratio of these gases, and/or by controllably adjusting the time, temperature, and/or pressure parameters of this anisotropic etching process.