Abstract:
A method of generating a mask for printing a pattern including a plurality of features. The method includes the steps of depositing a layer of transmissive material having a predefined percentage transmission on a substrate; depositing a layer of opaque material on the transmissive material; etching a portion of the substrate, the substrate being etched to a depth based on an etching selectivity between the transmissive layer and the substrate; exposing a portion of the transmissive layer by etching the opaque material; etching the exposed portion of the transmissive layer so as to expose an upper surface of the substrate; where the exposed portions of the substrate and the etched portions of the substrate exhibit a predefined phase shift relative to one another with respect to an illumination signal.
Abstract:
A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding- the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.
Abstract:
A method of generating complementary masks for use in a multiple-exposure lithographic imaging process. The method includes the steps of: identifying a target pattern having a plurality of features comprising horizontal and vertical edges; generating a horizontal mask based on the target pattern; generating a vertical mask based on the target pattern; performing a shielding step in which at least one of the vertical edges of the plurality of features in the target pattern is replaced by a shield in the horizontal mask, and in which at least one of the horizontal edges of the plurality of features in the target pattern is replaced by a shield in the vertical mask, where the shields have a width which is greater that the width of the corresponding feature in the target pattern; performing an assist feature placement step in which sub-resolution assist features are disposed parallel to at least one of the horizontal edges of the plurality of features in the horizontal mask, and are disposed parallel to at least one of the vertical edges of the plurality of features in the vertical mask, and performing a feature biasing step in which at least one of the horizontal edges of the plurality of features in the horizontal mask are adjusted such that the resulting feature accurately reproduces the target pattern, and at least one of the vertical edges of the plurality of features in the vertical mask are adjusted such that the resulting feature accurately reproduces the target pattern.
Abstract:
A method of forming a hybrid mask for optically transferring a lithographic pattern corresponding to an integrated circuit from the mask onto a semiconductor substrate by use of an optical exposure tool. The method includes the steps of forming at least one non-critical feature on the mask utilizing one of a low-transmission phase-shift mask (pattern) and a non-phase shifting mask (pattern), and forming at least one critical feature on the mask utilizing a high-transmission phase-shift mask (pattern).
Abstract:
A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding—the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.
Abstract:
A method of generating complementary masks for use in a multiple-exposure lithographic imaging process. The method includes the steps of: identifying a target pattern having a plurality of features comprising horizontal and vertical edges; generating a horizontal mask based on the target pattern; generating a vertical mask based on the target pattern; performing a shielding step in which at least one of the vertical edges of the plurality of features in the target pattern is replaced by a shield in the horizontal mask, and in which at least one of the horizontal edges of the plurality of features in the target pattern is replaced by a shield in the vertical mask, where the shields have a width which is greater that the width of the corresponding feature in the target pattern; performing an assist feature placement step in which sub-resolution assist features are disposed parallel to at least one of the horizontal edges of the plurality of features in the horizontal mask, and are disposed parallel to at least one of the vertical edges of the plurality of features in the vertical mask, and performing a feature biasing step in which at least one of the horizontal edges of the plurality of features in the horizontal mask are adjusted such that the resulting feature accurately reproduces the target pattern, and at least one of the vertical edges of the plurality of features in the vertical mask are adjusted such that the resulting feature accurately reproduces the target pattern.
Abstract:
A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.
Abstract:
A method of forming a mask having optical proximity correction features, which includes the steps of obtaining a target pattern of features to be imaged, expanding the width of the features to be imaged, modifying the mask to include assist features which are placed adjacent the edges of the features to be imaged, where the assist features have a length corresponding to the expanded width of the features to be imaged, and returning the features to be imaged from the expanded width to a width corresponding to the target pattern.
Abstract:
A method of generating a mask design having optical proximity correction features disposed therein. The methods includes the steps of obtaining a desired target pattern having features to be imaged on a substrate; determining an interference map based on the target pattern, the interference map defining areas of constructive interference and areas of destructive interference between at least one of the features to be imaged and a field area adjacent the at least one feature; and placing assist features in the mask design based on the areas of constructive interference and the areas of destructive interference.
Abstract:
A method for making a mask for optically transferring a lithographic pattern corresponding to an integrated circuit from the mask onto a semiconductor substrate by use of an optical exposure tool. The method includes the steps of de-composing the existing mask patterns into arrays of “imaging elements.” The imaging elements are &pgr;-phase shifted and are separated by non-phase shifting and sub-resolution elements referred to as anti-scattering bars (ASBs). In essence, the ASBs are utilized to de-compose the larger-than-minimum-width mask features to form “halftone-like” imaging patterns. The placement of the ASBs and the width thereof are such that none of the &pgr;-phase shifting elements are individually resolvable, but together they form patterns substantially similar to the intended mask features.