Self-aligned double patterning via enclosure design

摘要

A design methodology for determining a via enclosure rule for use with a self-aligned double pattern (SADP) technique is disclosed. The shape of the block mask serves as a criterion for choosing a via enclosure rule. Different block mask shapes within an integrated circuit design may utilize different rules and provide different margins for via enclosure. A tight via enclosure design rule reduces the margin of a line beyond the via where possible, while a loose via enclosure design rule increases the margin of a line beyond the via where it is beneficial to do so.

主权项

1. A method for computing via enclosure rules, comprising:
identifying, by at least one computing device, line termination modes in a self-aligned double patterning line pattern comprising a plurality of lines and vias; assigning, by the at least one computing device, a first via enclosure rule in response to identifying a line termination mode of inner vertex block mask, wherein the inner vertex block mask comprises at least one vertex that has an outer angle that is less than 180 degrees; and assigning, by the at least one computing device, a second via enclosure rule in response to identifying a line termination mode of outer vertex block mask, wherein the outer vertex block mask consists of vertices that have an outer angle that is greater than 180 degrees.