Interactively presenting for minimum overlap shapes in an IC design
Some embodiments provide a method for computing and displaying of minimum overlap for semiconductor layer interfaces, such as metal-via and metal-contact. The method leverages a machine-trained network (e.g., a trained neural network) to quickly, but accurately, infer the contours for the manufactured shapes across a range of process variations. The method also models the semiconductor process manufacturing layer-to-layer misalignment. The combined set of information (from the machine-trained network and from the modeling) is used by the method to compute the minimum overlap shapes at multiple layer interfaces. The method in some embodiments then uses the minimum overlap shapes to obtain an accurate calculation of the via or contact resistance.
1 . A method of designing an integrated circuit (IC) with a plurality of circuit elements, the method comprising:
for a layout of an IC design that has a plurality of interconnect layers and a multi-layer interface (i) connecting at least two IC-design circuit elements on a set of at least two interconnect layers, and (ii) comprising at least two components on the set of interconnect layers:
generating an animation that steps through a plurality of minimum overlap shapes for the multi-layer interface, wherein:
the minimum overlap shapes are shapes that are predicted to be produced after a manufacturing stage of a manufacturing process that is used to manufacture a semiconductor circuit from the design layout;
the animation comprises a plurality of sets of contours, each set of contours specifying a different set of shapes for the components of the interfaces on the different layers for a different variation of a manufacturing parameter of the manufacturing process; and
generating the animation comprises generating, for each manufacturing parameter variation, a predicted overlap shape for the interface by intersecting shapes of the interface components on the different layers as defined by the set of contours that specify the shapes of the interface components for the manufacturing parameter variation, said animation showing different predicted overlap shapes that are predicted to be produced for the different variations of the manufacturing process; and
displaying the animation on a display screen to aid in an assessment of the design layout.
2 . The method of claim 1 , wherein generating the animation further comprises:
identifying different alignments of the interface components on the different layers; and
generating, for each identified alignment, a predicted overlap shape for the interface by intersecting shapes of the interface components on the different layers when the components are aligned based on the identified alignment.
3 . The method of claim 2 , wherein identifying the different alignments comprises using a set of two or more alignment settings that are defined with respect to a vertical axis in order to identify two or more alignments of the interface components on the different layers.
4 . The method of claim 3 , wherein the alignment setting set specifies a range of one or more misalignments between the interconnect layers of the IC design, wherein the interconnect layers correspond to wiring layers of the IC.
5 . The method of claim 2 , wherein each interconnect layer is defined by reference to an x-axis and a y-axis and each interface component on each layer has a two-dimensional (2D) shape defined in the x- and y-axes of the layer of the interface component, wherein intersecting the shapes for each identified alignment comprises intersecting the 2D shapes of the interface components as the shapes are aligned based on the identified alignment.
6 . The method of claim 2 , wherein generating the predicted overlap shape for each identified alignment comprises generating, for each identified alignment, a plurality of predicted overlap shapes that represent a range of possible overlap shapes that are predicted to be produced based on the different variations of the manufacturing parameter of the manufacturing process.
7 . The method of claim 1 , wherein the different set of shapes for each parameter variation is generated by a machine-trained network.
8 . The method of claim 1 , wherein displaying the animation comprises overlaying the animation over a display of the IC design layout.
9 . A non-transitory machine readable medium storing an electronic design automation (EDA) program for designing an integrated circuit (IC) with a plurality of circuit elements, the program for execution by at least one processing unit of a computer, the program comprising sets of instructions for:
for a layout of an IC design that has a plurality of interconnect layers and a multi-layer interface (i) connecting at least two IC-design circuit elements on a set of at least two interconnect layers, and (ii) comprising at least two components on the set of interconnect layers:
generating an animation that steps through a plurality of minimum overlap shapes for the multi-layer interface, wherein:
the minimum overlap shapes are shapes that are predicted to be produced after a manufacturing stage of a manufacturing process that is used to manufacture a semiconductor circuit from the design layout;
the animation comprises a plurality of sets of contours, each set of contours specifying a different set of shapes for the components of the interfaces on the different layers for a different variation of a manufacturing parameter of the manufacturing process; and
the set of instructions for generating the animation comprises a set of instructions for generating, for each manufacturing parameter variation, a predicted overlap shape for the interface by intersecting shapes of the interface components on the different layers as defined by the set of contours that specify the shapes of the interface components for the manufacturing parameter variation, said animation showing different predicted overlap shapes that are predicted to be produced for the different variations of the manufacturing process; and
displaying the animation on a display screen to aid in an assessment of the design layout.
10 . The non-transitory machine readable medium of claim 9 , wherein the set of instructions for generating the animation further comprises sets of instructions for:
identifying different alignments of the interface components on the different layers; and
generating, for each identified alignment, a predicted overlap shape for the interface by intersecting shapes of the interface components on the different layers when the components are aligned based on the identified alignment.
11 . The non-transitory machine readable medium of claim 10 , wherein the set of instructions for identifying the different alignments comprises a set of instructions for using a set of two or more alignment settings that are defined with respect to a vertical axis in order to identify two or more alignments of the interface components on the different layers.
12 . The non-transitory machine readable medium of claim 10 , wherein each interconnect layer is defined by reference to an x-axis and a y-axis and each interface component on each layer has a two-dimensional (2D) shape defined in the x- and y-axes of the layer of the interface component, wherein intersecting the shapes for each identified alignment comprises intersecting the 2D shapes of the interface components as the shapes are aligned based on the identified alignment.
13 . The non-transitory machine readable medium of claim 10 , wherein the set of instructions for generating the predicted overlap shape for each identified alignment comprises a set of instructions for generating, for each identified alignment, a plurality of predicted overlap shapes that represent a range of possible overlap shapes that are predicted to be produced based on the different variations of the manufacturing parameter of the manufacturing process.
14 . The non-transitory machine readable medium of claim 9 , wherein the different set of shapes for each parameter variation is generated by a machine-trained network.
15 . The non-transitory machine readable medium of claim 9 , wherein the set of instructions for displaying the animation comprises a set of instructions for displaying each predicted minimum overlap shape for a duration of time.