摘要:
A method for decomposing a target pattern containing features to be printed on a wafer into multiple patterns. The method includes the steps of: (a) determining a minimum critical dimension and pitch associated with a process to be utilized to image the multiple patterns; (b) generating an anchoring feature; (c) disposing the anchoring feature adjacent a first feature of the target pattern; (d) growing the anchoring feature a predetermined amount so as to define a first area; (e) assigning any feature within the first area to a first pattern; (f) disposing the anchoring feature adjacent a second feature of the target pattern; (g) growing the anchoring feature the predetermined amount so as to define a second area; and (h) assigning any feature within the second area to a second pattern. Steps (c)-(h) are then repeated until the densely spaced features within the target pattern have been assigned to either the first or second pattern.
摘要:
A method for decomposing a target circuit pattern containing features to be imaged into multiple patterns. The process includes the steps of separating the features to be printed into a first pattern and a second pattern; performing a first optical proximity correction process on the first pattern and the second pattern; determining an imaging performance of the first pattern and the second pattern; determining a first error between the first pattern and the imaging performance of the first pattern, and a second error between the second pattern and the imaging performance of said second pattern; utilizing the first error to adjust the first pattern to generate a modified first pattern; utilizing the second error to adjust the second pattern to generate a modified second pattern; and applying a second optical proximity correction process to the modified first pattern and the modified second pattern.
摘要:
A method for forming exposure masks for imaging a target pattern having features to be imaged on a substrate in a multi-exposure process. The method includes the steps of generating a set of decomposition rules defining whether a given feature of the target pattern is assigned to a first exposure mask or a second exposure mask; applying the decomposition rules to each of the features in the target pattern so as to assign each of the features in the target pattern to one of the first exposure mask or second exposure mask; and generating the first exposure mask and the second exposure mask containing the respective features assigned to each mask.
摘要:
A method of generating a mask for printing a pattern including a plurality of features. The method includes the steps of obtaining data representing the plurality of features; and forming at least one of the plurality of features by etching a substrate to form a mesa and depositing a chrome layer over the entire upper surface of the mesa, where said mesa has a predetermined height.
摘要:
A method of generating complementary masks for use in a dark field double dipole imaging process. The method includes the steps of identifying a target pattern having a plurality of features, including horizontal and vertical features; generating a horizontal mask based on the target pattern, where the horizontal mask includes low contrast vertical features. The generation of the horizontal mask includes the steps of optimizing the bias of the low contrast vertical features contained in the horizontal mask; and applying assist features to the horizontal mask. The method further includes generating a vertical mask based on the target pattern, where the vertical mask contains low contrast horizontal features. The generation of the vertical mask includes the steps of optimizing the bias of low contrast horizontal features contained in the vertical mask; and applying assist features to the vertical mask.
摘要:
A method of generating complementary masks based on a target pattern having features to be imaged on a substrate for use in a multiple-exposure lithographic imaging process. The method includes the steps of: defining an initial H-mask corresponding to the target pattern; defining an initial V-mask corresponding to the target pattern; identifying horizontal critical features in the H-mask having a width which is less than a predetermined critical width; identifying vertical critical features in the V-mask having a width which is less than a predetermined critical width; assigning a first phase shift and a first percentage transmission to the horizontal critical features, which are to be formed in the H-mask; and assigning a second phase shift and a second percentage transmission to the vertical critical features, which are to be formed in the V-mask. The method further includes the step of assigning chrome to all non-critical features in the H-mask and the V-mask. The non-critical features are those features having a width which is greater than or equal to the predetermined critical width. The non-critical features are formed in the H-mask and the V-mask utilizing chrome. The target pattern is then imaged on the substrate by imaging both the H-mask and V-mask.
摘要:
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.
摘要:
Optical proximity effects (OPEs) are a well-known phenomenon in photolithography. OPEs result from the structural interaction between the main feature and neighboring features. It has been determined by the present inventors that such structural interactions not only affect the critical dimension of the main feature at the image plane, but also the process latitude of the main feature. Moreover, it has been determined that the variation of the critical dimension as well as the process latitude of the main feature is a direct consequence of light field interference between the main feature and the neighboring features. Depending on the phase of the field produced by the neighboring features, the main feature critical dimension and process latitude can be improved by constructive light field interference, or degraded by destructive light field interference. The phase of the field produced by the neighboring features is dependent on the pitch as well as the illumination angle. For a given illumination, the forbidden pitch region is the location where the field produced by the neighboring features interferes with the field of the main feature destructively. The present invention provides a method for determining and eliminating the forbidden pitch region for any feature size and illumination condition. Moreover, it provides a method for performing illumination design in order to suppress the forbidden pitch phenomena, and for optimal placement of scattering bar assist features.
摘要:
Optical proximity effects (OPEs) are a well-known phenomenon in photolithography. OPEs result from the structural interaction between the main feature and neighboring features. It has been determined by the present inventors that such structural interactions not only affect the critical dimension of the main feature at the image plane, but also the process latitude of the main feature. Moreover, it has been determined that the variation of the critical dimension as well as the process latitude of the main feature is a direct consequence of light field interference between the main feature and the neighboring features. Depending on the phase of the field produced by the neighboring features, the main feature critical dimension and process latitude can be improved by constructive light field interference, or degraded by destructive light field interference. The phase of the field produced by the neighboring features is dependent on the pitch as well as the illumination angle. For a given illumination, the forbidden pitch region is the location where the field produced by the neighboring features interferes with the field of the main feature destructively. The present invention provides a method for determining and eliminating the forbidden pitch region for any feature size and illumination condition. Moreover, it provides a method for performing illumination design in order to suppress the forbidden pitch phenomena, and for optimal placement of scattering bar assist features.
摘要:
A method of generating a mask for use in an imaging process pattern. The method includes the steps of: (a) obtaining a desired target pattern having a plurality of features to be imaged on a substrate; (b) simulating a wafer image utilizing the target pattern and process parameters associated with a defined process; (c) defining at least one feature category; (d) identifying features in the target pattern that correspond to the at least one feature category, and recording an error value for each feature identified as corresponding to the at least one feature category; and (e) generating a statistical summary which indicates the error value for each feature identified as corresponding to the at least one feature category.