Method and mechanism for implementing DFM aware cells for an electronic design

• US 7,506,277 B1
• Filed: 07/11/2006
• Issued: 03/17/2009
• Est. Priority Date: 07/28/2005
• Status: Expired due to Fees

• Current Assignee: Cadence Design Systems Incorporated (Cadence Group)
• Original Assignee: Cadence Design Systems Incorporated (Cadence Group)
• Inventors: Jain, Anurag, Arora, Rajan, Sisodia, Umesh
• Primary Examiner(s): Do; Thuan
• Assistant Examiner(s): Dimyan; Magid Y
• Application Number:
  US11/485,039
• Time in Patent Office: 980 Days
• Field of Search: 716/5, 716/9, 716/10, 716/11, 716/1
• US Class Current: 716/122
• CPC Class Codes: G06F 2115/06 Structured ASICs
• CPC Class Codes: G06F 30/398 Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] optical proximity correction [OPC] design processes G03F1/36

Abstract

An improved method, system, computer program product, and electronic design structures which provides the flexibility to IC designers to be able to relax the design rules to increase the yield and improve the layout productivity is disclosed. In some disclosed approaches, automated interactive aids and batch tools are provided which can assist in optimizing the final layouts for yield at the initial placement and/or routing stages for optimizing yield. Provided in some disclosed approaches are automated capability to layout designers at the mos devices level to configure mos devices as per different DFY recommendations from the foundry without negative effects on the overall chip area (or cell size). The design rules may be relaxed selectively on an instance basis and wherever possible or desirable.

Claims

1. A method of allowing relaxed design rules when implementing an integrated circuit design, comprising:

defining a design for manufacturing (DFM) rule, the DFM rule corresponding to an alternate design rule from minimum design rule check (DRC) rules;

defining a set of one or more of the DFM rules as a constraint group;

associating the constraint group with an intelligent design parameterized cell master;

applying the constraint group on an instance of the intelligent design parameterized cell master to an intelligent design cell to override a default DRC rule for the integrated circuit design; and

performing layout of the integrated circuit design.

2. The method of claim 1 in which the intelligent design cell comprises either a Ouick Cell (QCell or a Parameterized cell (Pcell).

3. The method of claim 2 in which the constraint group is stored as a class parameter.

4. The method of claim 1 in which the DFM rule and the constraint group information are stored in a technology library.

5. The method of claim 4 in which the DFM rule is technology specific.

6. The method of claim 1 in which the DFM rule or constraint group provides a different level of relaxation compared to a corresponding DRC rule.

7. The method of claim 1 in which the DFM rule comprises a minimum spacing rule, minimum extension rule, or minimum enclosure rule.

8. The method of claim 7 in which the minimum spacing rule, minimum extension rule, or minimum enclosure rule comprises any one of a poly end cap rule, active to poly spacing rule, poly to poly spacing rule, active enclosure of contact rule, metal enclosure of contact rule, poly to contact spacing rule, or an MOS-specific DRC rule.

9. The method of claim 8 in which different constraint groups are chosen for different DFM rules.

10. The method of claim 8 in which a single constraint group comprises multiple DFM rules.

11. The method of claim 1 in which the act of applying the constraint group on the instance of the intelligent design cell master to the intelligent design cell is performed at time of device generation.

12. The method of claim 1 in which multiple iterations of the method is performed during layout processing of the integrated circuit design.

13. The method of claim 1 in which the method is applied to specific regions of the integrated circuit design.

14. The method of claim 1 in which the integrated circuit design is traversed hierarchically to flag areas for which the DRC rules can be relaxed without sacrificing layout area.

15. The method of claim 1 in which the integrated circuit design is relaxed without increasing layout area.

16. A computer program product comprising a tangible computer usable medium having executable code to execute a process for allowing relaxed design rules when implementing an integrated circuit design, the process comprising:

defining a design for manufacturing (DFM) rule, the DFM rule corresponding to an alternate design rule from minimum design rule check (DRC) rules;

defining a set of one or more of the DFM rules as a constraint group;

associating the constraint group with an intelligent design parameterized cell master;

applying the constraint group on an instance of the intelligent design parameterized cell master to an intelligent design cell to override a default DRC rule for the integrated circuit design; and

performing layout of the integrated circuit design.

17. The product of claim 16 in which multiple iterations of the process are performed during layout processing of the integrated circuit design.

18. A system for allowing relaxed design rules when implementing an integrated circuit design, comprising:

means for defining a design for manufacturing (DFM) rule, the DFM rule corresponding to an alternate design rule from minimum design rule check (DRC) rules;

means for defining a set of one or more of the DFM rules as a constraint group;

means for associating the constraint group with an intelligent design parameterized cell master;

means for applying the constraint group on an instance of the intelligent design parameterized cell master to an intelligent design cell to override a default DRC rule for the integrated circuit design; and

means for performing layout of the integrated circuit design.

19. The system of claim 18 in which the constraint group is stored as a class parameter.

20. The system of claim 18 in which the DFM rule or constraint group provides a different level of relaxation compared to a corresponding DRC rule.