Patent Number: 6,165,693

Title: Method of designing an assist feature

Abstract: For a dense-line mask pattern, if the ratio of space width to line width is larger than 2.0 and the size of the line width is less than the exposure wave length, or for an iso-line mask pattern, if the size of the line width is less than the exposure wave length, assist features should be added and OAI should be used to increase the process window. For a dense-line mask pattern, if the ratio of space width to line width is smaller than 2.0, or for an iso-line mask pattern, if the size of the line width is larger than the exposure wavelength, no assist feature should be added.

Inventors: Lin; Chin-Lung (Kaohsiung, TW), Ku; Yao-Ching (Hsinchu Hsien, TW)

Assignee: United Microelectronics Corp.

International Classification: G03F 1/14 (20060101); G03C 005/00 ()

Expiration Date: 12/26/2017