Abstract: A design level compatible with a sidewall image transfer process employs an alternating grid of mandrel-type line tracks and non-mandrel-type line tracks. Target structure design shapes are formed such that all vertices of the target structure design shapes are on the grid. The target structure design shapes are classified as mandrel-type design shapes and non-mandrel-type design shapes depending on the track type of the overlapping line tracks for lengthwise portions. All mandrel-type line tracks and straps of the mandrel-type design shapes less lateral strap regions of the non-mandrel-type design shapes collectively form mandrel design shapes, which can be employed to generate a first lithographic mask. Sidewall design shapes are generated from the mandrel design shapes. Blocking shapes for a second lithographic mask can be generated by selecting all areas that are not included in the target structure design shapes or the sidewall design shapes.

Abstract: A design level compatible with a sidewall image transfer process employs an alternating grid of mandrel-type line tracks and non-mandrel-type line tracks. Target structure design shapes are formed such that all vertices of the target structure design shapes are on the grid. The target structure design shapes are classified as mandrel-type design shapes and non-mandrel-type design shapes depending on the track type of the overlapping line tracks for lengthwise portions. All mandrel-type line tracks and straps of the mandrel-type design shapes less lateral strap regions of the non-mandrel-type design shapes collectively form mandrel design shapes, which can be employed to generate a first lithographic mask. Sidewall design shapes are generated from the mandrel design shapes. Blocking shapes for a second lithographic mask can be generated by selecting all areas that are not included in the target structure design shapes or the sidewall design shapes.

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.

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.