Line Search-Based Inverse Lithography Technique for Mask Design

Algorithm 1

Generic framework for iterative gradient-based search. Note that specific details about our algorithm are given in the comments.

(1) Transform initial mask into β // Section 4.1

(2) Repeat

(3)  Find the search direction d at β // Equation (12)

(4)   Determine the step size S // Section 4.2

(5)  β ^new = β + S * d

(6)   Generate gray mask M = T(β ^new) // Equation (11)

(7)   // Round M to binary as described in Section 4.4

(8)   Evaluate pattern error E(M) // Equations (2), (3), and (6)

(9)   β = β ^new

(10) Until pattern error is not improving