| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for forming a fine pattern having a pitch smaller than the resolution of an exposure system. <P>SOLUTION: Resist is coated on a silicon nitride film 3a formed on an interlayer insulating film 2, and a resist pattern 4a having a rough pitch is formed by lithography. The silicon nitride film 3a is etched to have a thickness corresponding to 1/2 of the initial film thickness with use of the resist pattern 4a as a mask, and then the resist pattern 4a is removed. Next, resist is again coated on the silicon nitride film 3a, and a resist pattern 4b is formed so that lines are arranged between lines of the pattern formed by the resist pattern 4a. The silicon nitride film 3a is then etched to have a thickness corresponding to 1/2 of the initial film thickness with use of the resist pattern 4a as a mask. As a result, a hard mask 3 of silicon nitride and having a high-pitch pattern formed thereon is formed. The interlayer insulating film 2 is etched with the use of the hard mask 3 as a mask. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
