Abstract: A method for forming a photomask includes following operations. A first photomask is received. The first photomask includes a first pattern and a first scattering bar. The first photomask is used to remove a first portion of a target layer to form a first opening and a second opening. The first opening corresponds to the first pattern, and the second opening corresponds to the first scattering bar. A second photomask is received. The second photomask includes a second pattern. The second photomask is used to remove a second portion of the target layer to form a third opening. The third opening corresponds to the second pattern. The second opening is widened to form the third opening using the second photomask.

Abstract: A method for forming a photomask is provided. The method includes: receiving an initial layout, the initial layout comprising a first pattern and a second pattern; decomposing the initial layout into a first layout including the first pattern and a second layout including the second pattern; inserting a third pattern into the first layout; overlapping the first layout including the first pattern and the third pattern to the second layout including the second pattern; increasing a width of the third pattern in the first layout overlapping the second pattern in the second layout to form a fourth pattern in the first layout; and outputting the first layout comprising the first pattern, the third pattern and the fourth pattern into a first photomask.

Abstract: A method for forming a photomask is provided. The method includes: receiving an initial layout, the initial layout comprising a first pattern and a second pattern; decomposing the initial layout into a first layout including the first pattern and a second layout including the second pattern; inserting a third pattern into the first layout; overlapping the first layout including the first pattern and the third pattern to the second layout including the second pattern; increasing a width of the third pattern in the first layout overlapping the second pattern in the second layout to form a fourth pattern in the first layout; and outputting the first layout comprising the first pattern, the third pattern and the fourth pattern into a first photomask.

Abstract: A method for forming a photomask is provided. The method includes: receiving an initial layout including a plurality of first patterns and a plurality of second patterns; decomposing the initial layout into a first layout including the plurality of first patterns and a second layout including the plurality of second patterns; inserting a plurality of third patterns into the first layout, wherein each of the plurality of third patterns is adjacent to at least one of the plurality of first patterns; comparing the first layout and the second layout; identifying a fourth pattern as an overlapping portion of the plurality of third patterns overlapping one of the plurality of second patterns; increasing a width of the fourth pattern; and outputting the first layout including the first patterns, the third patterns and the fourth patterns into a first photomask.

Abstract: A method for forming a photomask is provided. The method includes: receiving an initial layout including a plurality of first patterns and a plurality of second patterns; decomposing the initial layout into a first layout including the plurality of first patterns and a second layout including the plurality of second patterns; inserting a plurality of third patterns into the first layout, wherein each of the plurality of third patterns is adjacent to at least one of the plurality of first patterns; comparing the first layout and the second layout; identifying a fourth pattern as an overlapping portion of the plurality of third patterns overlapping one of the plurality of second patterns; increasing a width of the fourth pattern; and outputting the first layout including the first patterns, the third patterns and the fourth patterns into a first photomask.

Abstract: A method, of seeding an optical proximity correction (OPC) process, includes: receiving, at an input device of a computer, a subject pre-OPC design-signature for a subject pre-OPC design package; selecting, by the processor and via interaction with an OPC database operatively connected to the computer, one amongst archived post-OPC design packages based on relatedness between the subject pre-OPC design-signature and archived post-OPC design-signatures corresponding to the archived post-OPC design packages, and thereby retrieving the selected archived post-OPC design packages; and generating one or more seeds for the OPC process based on the selected archived post-OPC design package.

Abstract: A method, of seeding an optical proximity correction (OPC) process, includes: receiving, at an input device of a computer, a subject pre-OPC design-signature for a subject pre-OPC design package; selecting, by the processor and via interaction with an OPC database operatively connected to the computer, one amongst archived post-OPC design packages based on relatedness between the subject pre-OPC design-signature and archived post-OPC design-signatures corresponding to the archived post-OPC design packages, and thereby retrieving the selected archived post-OPC design packages; and generating one or more seeds for the OPC process based on the selected archived post-OPC design package.

Abstract: Methods and apparatus of performing layout-versus-layout (LVL) comparison are disclosed. A layout may be in various formats such as GDSII or OASIS, for different circuits, and represented by a basic layout element, a hierarchical cell or a plurality of independent cells in various layers. A basic layout element, a hierarchical cell, and a layout with a plurality of independent cells may have a signature generated according to the embodiment methods. The signature of a basic layout element may be generated based on values of a center and a circumference, and a hashed trace value generated by a hash function of a trace of the basic layout element. The signature of a hierarchical cell can be generated recursively. A signature of a first layout may be compared to a signature of a second layout to determine whether the first layout matches the second layout.

Abstract: Methods and apparatus of performing layout-versus-layout (LVL) comparison are disclosed. A layout may be in various formats such as GDSII or OASIS, for different circuits, and represented by a basic layout element, a hierarchical cell or a plurality of independent cells in various layers. A basic layout element, a hierarchical cell, and a layout with a plurality of independent cells may have a signature generated according to the embodiment methods. The signature of a basic layout element may be generated based on values of a center and a circumference, and a hashed trace value generated by a hash function of a trace of the basic layout element. The signature of a hierarchical cell can be generated recursively. A signature of a first layout may be compared to a signature of a second layout to determine whether the first layout matches the second layout.