US 2004/0166418 A1 · METHOD OF OPTICAL PROXIMITY CORRECTION WITH SUB-RESOLUTION ASSISTS

Abstract

A first aspect of the present invention is a method of determining an optical proximity correction for a primary feature having sub-resolution assist features for increasing the depth of focus of the primary features, comprising: generating a line/space pair; placing sub-resolution assist features on opposite sides of the line of the line/space pair; generating a set of linewidth biases; applying the set of linewidth biases to the line of the line/space pair to generate a set of biased-line/space pairs; determining for each biased-line/space pair, a deviation from a design linewidth of the line/space pair when the set of biased-line/space pairs are printed or simulated; and determining from the deviation a correction bias to apply to the line of the line/space pair. The invention also encompasses apparatus and computer programs for carrying out the methods.

Claims23

Dependent claims

A method of determining an optical proximity correction for a primary feature having sub-resolution assist features for increasing the depth of focus of said primary features, comprising:

generating a line/space pair;
placing sub-resolution assist features on opposite sides of the line of said line/space pair;
generating a set of linewidth biases;
applying said set of linewidth biases to the line of said line/space pair to generate a set of biased-line/space pairs;
determining for each biased-line/space pair, a deviation from a design linewidth of said line/space pair when said set of biased-line/space pairs are printed or simulated;
and
determining from said deviation a correction bias to apply to the line of said line/space pair.

4 more elements

A method of determining a set of optical proximity correction rules for primary features having sub-resolution assist features for increasing the depth of focus of said primary features, comprising:

generating a grating, said grating comprising sets of sets of line/space pairs, each set of line space/pairs comprising multiple copies of a unique combination of a linewidth value and a spacewidth value;
generating a set of linewidth biases;
for each line/space pair of a particular set of line/space pairs;
selecting a sub-resolution assist features from a set of sub-resolution assist features based on said spacewidth value of said line/width pair of said particular set of line/space pairs;
placing said sub-resolution assist features on either side of each line of each line/space pair of said particular set of line/space pairs;
and
applying a different linewidth bias of said set of linewidth bias to each line of each line/space pair of said particular set of line/space pairs;
determining deviations from design linewidths of said sets of line/space pairs produced by said applying said different linewidth bias of said set of linewidth bias to each line of each line/space pair of said particular set of line/space pair;
and
generating from said deviations from said design linewidths of said set of line/space pairs said set of optical proximity correction rules.

7 more elements

A method of optical proximity correction of primary features of a design having sub-resolution assist features for increasing the depth of focus of said primary features during operation of an optical lithography system by width biasing a light blocking layer on an optical mask, comprising:

(a) selecting a set of line/space pairs representative of each said feature;
(b) for each line/space pair of said set of line/space pairs;
(i) generating, an identical set of line/space pairs representative of said feature;
(ii) placing sub-resolution assist features on opposite sides of each line of each line/space pair, selection of said sub-resolution assist features based on linewidth and space values of said line/space pair;
(iii) generating a set of linewidth biases;
(iv) applying said a different linewidth bias of said set of linewidth biases to the line of each line/space pair to generate a set of biased-line/space pairs;
(v) determining for each biased-line/width pair, a deviation from a design linewidth of said line/space pair when said set of biased-line/space pairs are printed or simulated;
and
(vi) determining from said deviations, a set of optical proximity correction rules corresponding to each line/space pair, each rule comprising a correction bias;
selecting a feature from said primary features;
(d) determining a corresponding line/space pair from said set of line/space pairs representative of said feature;
(e) placing sub-resolution assist features on opposite sides of said feature, selection of said sub-resolution assist feature based on linewidth and space values of said line/space pair representative of said feature;
(f) selecting a correction bias from said set of optical proximity correction rules, selection of said correction bias based on linewidth and space values of said line/space pair representative of said feature;
and
(g) applying said correction bias to said feature.

12 more elements

Dependencies are inferred from the claim text.

Method of optical proximity correction with sub-resolution assists

Life of this patent

Method of optical proximity correction with sub-resolution assists

Life of this patent

Abstract

Claims23