Patent Number: 8,716,133

Title: Three photomask sidewall image transfer method

Abstract: A three photomask image transfer method. The method includes using a first photomask, defining a set of mandrels on a hardmask layer on a substrate; forming sidewall spacers on sidewalls of the mandrels, the sidewall spacers spaced apart; removing the set of mandrels; using a second photomask, removing regions of the sidewall spacers forming trimmed sidewall spacers and defining a pattern of first features; forming a pattern transfer layer on the trimmed sidewall spacers and the hardmask layer not covered by the trimmed sidewall spacers; using a third photomask, defining a pattern of second features in the transfer layer, at least one of the second features abutting at least one feature of the pattern of first features; and simultaneously transferring the pattern of first features and the pattern of second features into the hardmask layer thereby forming a patterned hardmask layer.

Inventors: Chen; Shyng-Tsong (Patterson, NY), Jung; Ryan O. (Rensselaer, NY), Lafferty; Neal V. (Albany, NY), Yin; Yunpeng (Niskayuna, NY)

Assignee: International Business Machines Corporation

International Classification: H01L 21/44 (20060101)

Expiration Date: 5/06/12018