METHOD OF FORMING FINE PATTERNS OF SEMICONDUCTOR DEVICE USING DOUBLE PATTERNING PROCESS

摘要

A method for forming a fine pattern of a semiconductor device by using a double patterning process is provided to improve defects due to an etch rate difference and an etch depth difference between regions by securing a sufficient etch process margin. A plurality of multilayer mask patterns including a first mask pattern(130a) and a buffer mask pattern(132a) is formed on an etching target layer(120) of a substrate(100). A second mask pattern(150b) is formed on the etching target layer in a space between the multilayer mask patterns such that the upper surface of the second mask pattern is higher than those of the multilayer mask patterns. The buffer mask pattern is removed to expose the upper surface of the first mask pattern. A fine pattern is formed by etching the etching target layer by using the first and second mask patterns as etch masks.