Sub-resolution assist feature to improve symmetry for contact hole lithography
First Claim
Patent Images
1. A method of making a mask design having optical proximity correction features, comprising:
- obtaining a target pattern comprising a plurality of target pattern features corresponding to a plurality of features to be imaged on a substrate;
generating a mask design comprising mask features corresponding to the plurality of features to be imaged on the substrate, wherein a first and a second mask feature of the mask features are spaced along a first direction by a pitch (Px1) and the second mask feature is spaced from a third mask feature of the mask features along the first direction by a pitch (Px2);
determining a relationship between (i) a pitch of the first and second mask features and the second and third mask features, and (ii) a spacing of sub-resolution assist features from their corresponding first and third mask features, wherein the relationship provides an indication of an aspect ratio of at least one of the features to be imaged on the substrate corresponding to one of the first and third mask features; and
controlling the aspect ratio of the at least one of the features to be imaged on the substrate by positioning one of the sub-resolution assist features proximate to the corresponding mask feature, wherein the sub-resolution assist feature corresponding to the first mask feature is spaced from the first mask feature by a distance (x1), wherein (x1) is determined based on (Px1), and wherein the sub-resolution assist feature corresponding to the third mask feature is spaced from the third mask feature by a distance (x2), such that (x2) approximately equals (x1) when (Px2) approximately equals (Px1), and (x2) is different from (x1) when (Px2) is different from (Px1).
1 Assignment
0 Petitions
Accused Products
Abstract
A method of making a mask design having optical proximity correction features is provided. The method can include obtaining a target pattern comprising a plurality of target pattern features corresponding to a plurality of features to be imaged on a substrate. The method can also comprise generating a mask design comprising mask features corresponding to the plurality of features to be imaged on the substrate and controlling the aspect ratio of at least one of the features of the plurality of features to be imaged on the substrate by positioning a sub-resolution assist feature proximate to the corresponding mask feature.
-
Citations
7 Claims
-
1. A method of making a mask design having optical proximity correction features, comprising:
-
obtaining a target pattern comprising a plurality of target pattern features corresponding to a plurality of features to be imaged on a substrate; generating a mask design comprising mask features corresponding to the plurality of features to be imaged on the substrate, wherein a first and a second mask feature of the mask features are spaced along a first direction by a pitch (Px1) and the second mask feature is spaced from a third mask feature of the mask features along the first direction by a pitch (Px2); determining a relationship between (i) a pitch of the first and second mask features and the second and third mask features, and (ii) a spacing of sub-resolution assist features from their corresponding first and third mask features, wherein the relationship provides an indication of an aspect ratio of at least one of the features to be imaged on the substrate corresponding to one of the first and third mask features; and controlling the aspect ratio of the at least one of the features to be imaged on the substrate by positioning one of the sub-resolution assist features proximate to the corresponding mask feature, wherein the sub-resolution assist feature corresponding to the first mask feature is spaced from the first mask feature by a distance (x1), wherein (x1) is determined based on (Px1), and wherein the sub-resolution assist feature corresponding to the third mask feature is spaced from the third mask feature by a distance (x2), such that (x2) approximately equals (x1) when (Px2) approximately equals (Px1), and (x2) is different from (x1) when (Px2) is different from (Px1). - View Dependent Claims (2, 3, 4, 5)
-
-
6. A computer readable medium containing program code that configures a processor to perform a method for forming a mask design having optical proximity correction features, comprising:
-
program code for obtaining a target pattern comprising a plurality of target pattern features corresponding to a plurality of features to be imaged on a substrate; program code for generating a mask design comprising mask features corresponding to the plurality of features to be imaged on the substrate, wherein a first and a second mask feature of the mask features are spaced along a first direction by a pitch (Px1) and the second mask feature is spaced from a third mask feature of the mask features along the first direction by a pitch (Px2); program code for determining a relationship between (i) a pitch of the first and second mask features and the second and third mask features, and (ii) a spacing of sub-resolution assist features from their corresponding first and third mask features, wherein the relationship provides an indication of an aspect ratio of at least one of the features to be imaged on the substrate corresponding to one of the first and third mask features; and program code for controlling the aspect ratio of the at least one of the features to be imaged on the substrate by positioning one of the sub-resolution assist features proximate to the corresponding mask feature, wherein the sub-resolution assist feature corresponding to the first mask feature is spaced from the first mask feature by a distance (x1), wherein (x1) is determined based on (Px1), and wherein the sub-resolution assist feature corresponding to the third mask feature is spaced from the third mask feature by a distance (x2), such that (x2)approximately equals (x1) when (Px2) approximately equals (Px1), and (x2) is different from (x1) when (P2) is different from (Px1). - View Dependent Claims (7)
-
Specification