Patent ID: 8071487

Claim:
A patterning method for forming an opening pattern with a predetermined opening width in a material layer, comprising: providing a substrate having the material layer formed thereon; forming an underlayer on the material layer; forming a silicon rich organic layer on the underlayer; forming a hard mask layer between the material layer and the under layer; forming a photoresist layer on the silicon rich organic layer; patterning the photoresist layer to form an opening pattern in the photoresist layer; etching the silicon rich organic layer with the photoresist layer serving as a mask to transfer the opening pattern to the silicon rich organic layer; etching the underlayer with the silicon rich organic layer serving as the mask to transfer the opening pattern to the underlayer, wherein, when the opening pattern is completely transferred to the underlayer, the photoresist layer is completely etched away; etching the material layer with the underlayer serving as the mask to transfer the opening pattern to the material layer, wherein, when the opening pattern is completely transferred to the material layer, the silicon rich organic layer is completely etched away; and after etching the underlayer and before etching the material layer, etching the hard mask layer with the silicon rich organic layer and the underlayer as mask to transfer only the opening pattern to only the hard mask layer and not to any other layer, and when the opening pattern is completely transferred to the hard mask layer, the silicon rich organic layer is completely etched away.