Method of forming pattern

摘要

A method of forming a desired rectangular pattern in a material layer above a substrate. The method includes providing a substrate having a material layer thereon. A hard mask layer is next formed over the material layer, and then a first photoresist layer having a first pattern therein is formed over the hard mask layer. A first etching operation is carried out while using the first photoresist layer as an etching mask to remove a portion of the hard mask layer, thereby transferring the pattern in the first photoresist layer to the hard mask layer. The first photoresist layer is removed. A second photoresist layer having a second pattern therein is formed over the substrate. A second etching operation is carried out to remove a portion of the material layer while using the patterned second photoresist layer and the hard mask layer as an etching mask. Hence, the desired rectangular pattern is formed in the material layer.