Model-based fill
View Patent ↗Various aspects of this disclosure relate to increasing pattern density in a circuit layout design of a circuit layer so as to control the thickness of material in a manufactured integrated circuit. For example, a layer in circuit design may be divided into separate areas, and a target thickness range may be established for all of the tiles in the integrated circuit design. Each area may be analyzed to determine if it has a sufficient pattern density for a thickness estimation model to accurately estimate its expected material thickness upon manufacture. Each tile may be analyzed to determine if the expected thickness for that tile is within the target thickness range.
1. A method, comprising:
determining that a portion of an integrated circuit design complies with one or more specified pattern density criterion, and
upon determining that the portion of the integrated circuit design does not comply with the one or more specified pattern density criterion, then:
(a) selecting a fill pattern shape from a plurality of fill pattern shapes,
(b) determining an amount of the selected fill pattern shape to be added to the portion of the integrated circuit design in order for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density,
(c) determining a potential pattern perimeter-to-area ratio for the portion of the integrated circuit design if the amount of the selected fill pattern shapes is added to the portion of the integrated circuit design, and
(d) determining an expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio;
repeating, by a computing device, steps (a) through (d) until a successful fill pattern shape is selected that provides an expected material thickness for the portion of the integrated circuit design that is above a target material thickness; and
adding, to the portion of the integrated circuit design, the amount of the successful selected fill pattern shape that provides the expected material thickness for the portion of the integrated circuit design that is above the target material thickness.
2. The method recited in claim 1 , wherein determining the expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio includes employing a look up table.
3. The method recited in claim 1 , wherein the one or more specified pattern density criterion includes at least one of:
in integrated circuit pattern density above a specified pattern density, or
an integrated circuit pattern perimeter-to-area ratio above a specified pattern perimeter-to-area.
4. The method recited in claim 1 , further comprising:
while repeating steps (a) through (d) until a successful fill pattern shape is selected, determining that any amount of a particular selected fill pattern shape to be added to the portion of the integrated circuit design does not allow for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density and, in response, repeating steps (a) through (d) with a different selected fill shape.
5. An apparatus, comprising:
one or more processors;
memory storing executable instructions configured to, when executed by the one or more processors, cause the apparatus to:
determine that a portion of an integrated circuit design complies with one or more specified pattern density criterion, and
upon determining that the portion of the integrated circuit design does not comply with the one or more specified pattern density criterion, then:
(a) select a fill pattern shape from a plurality of fill pattern shapes,
(b) determine an amount of the selected fill pattern shape to be added to the portion of the integrated circuit design in order for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density,
(c) determine a potential pattern perimeter-to-area ratio for the portion of the integrated circuit design if the amount of the selected fill pattern shapes is added to the portion of the integrated circuit design, and
(d) determine an expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio;
repeat steps (a) through (d) until a successful fill pattern shape is selected that provides an expected material thickness for the portion of the integrated circuit design that is above a target material thickness; and
add, to the portion of the integrated circuit design, the amount of the successful selected fill pattern shape that provides the expected material thickness for the portion of the integrated circuit design that is above the target material thickness.
6. The apparatus recited in claim 5 , wherein determining the expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio includes employing a look up table.
7. The apparatus recited in claim 5 , wherein the one or more specified pattern density criteria includes at least one of:
an integrated circuit pattern density above a specified pattern density, or
an integrated circuit pattern perimeter-to-area ratio above a specified pattern perimeter-to-area.
8. The apparatus recited in claim 5 , wherein the memory further stores executable instructions configured to, when executed by the one or more processors, cause the apparatus to:
while repeating steps (a) through (d) until a successful fill pattern shape is selected, determine that any amount of a particular selected fill pattern shape to be added to the portion of the integrated circuit design does not allow for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density and, in response, repeat steps (a) through (d) with a different selected fill shape.
9. One or more computer readable storage devices, storing executable instructions configured to, when executed by one or more processors, cause an apparatus to:
determine that a portion of an integrated circuit design complies with one or more specified pattern density criterion, and
upon determining that the portion of the integrated circuit design does not comply with the one or more specified pattern density criterion, then:
(a) select a fill pattern shape from a plurality of fill pattern shapes,
(b) determine an amount of the selected fill pattern shape to be added to the portion of the integrated circuit design in order for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density,
(c) determine a potential pattern perimeter-to-area ratio for the portion of the integrated circuit design if the amount of the selected fill pattern shapes is added to the portion of the integrated circuit design, and
(d) determine an expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio;
repeat steps (a) through (d) until a successful fill pattern shape is selected that provides an expected material thickness for the portion of the integrated circuit design that is above a target material thickness; and
add, to the portion of the integrated circuit design, the amount of the successful selected fill pattern shape that provides the expected material thickness for the portion of the integrated circuit design that is above the target material thickness.
10. The one or more computer readable storage devices recited in claim 9 , wherein determining the expected material thickness for the portion of the integrated circuit design based upon the potential pattern density and the potential pattern perimeter-to-area ratio includes employing a look up table.
11. The one or more computer readable storage devices recited in claim 9 , wherein the one or more specified pattern density criteria includes at least one of:
an integrated circuit pattern density above a specified pattern density, or
an integrated circuit pattern perimeter-to-area ratio above a specified pattern perimeter-to-area.
12. The one or more computer readable storage media devices recited in claim 9 , further storing executable instructions configured to, when executed by the one or more processors, cause the apparatus to:
while repeating steps (a) through (d) until a successful fill pattern shape is selected, determine that any amount of a particular selected fill pattern shape to be added to the portion of the integrated circuit design does not allow for the portion of the integrated circuit design to have a potential pattern density greater than a target pattern density and, in response, repeat steps (a) through (d) with a different selected fill shape.