Design rule checking system and method

• US 6,470,489 B1
• Filed: 09/16/1998
• Issued: 10/22/2002
• Est. Priority Date: 09/17/1997
• Status: Expired due to Term

• Current Assignee: Synopsys Merger Holdings LLC (Synopsys Incorporated)
• Original Assignee: Numerical Technologies Inc. (Synopsys Incorporated)
• Inventors: Wang, Yao-Ting, Chang, Fang-Cheng, Pati, Yagyensh C.
• Primary Examiner(s): Siek, Vuthe
• Application Number:
  US09/153,783
• Time in Patent Office: 1,497 Days
• Field of Search: 716/21, 716/19, 716/20, 716/4, 716/3, 716/8-11, 430/5, 430/22, 430/30
• US Class Current: 716/52
• CPC Class Codes: G03F 1/36 Masks having proximity correction features; Preparation thereof, e.g. optical proximity correction [OPC] design processes
• CPC Class Codes: G06F 2119/18 Manufacturability analysis or optimisation for manufacturability
• 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

A method for performing design rule checking on OPC corrected or otherwise corrected designs is described. This method comprises accessing a corrected design and generating a simulated image. The simulated image corresponds to a simulation of an image which would be printed on a wafer if the wafer were exposed to an illumination source directed through the corrected design. The characteristics of the illumination source are determined by a set of lithography parameters. In creating the image, additional characteristics can be used to simulate portions of the fabrication process. However, what is important is that a resulting simulated image is created. The simulated image can then be used by the design rule checker. Importantly, the simulated image can be processed to reduce the number of vertices in the simulated image, relative to the number of vertices in the OPC corrected design layout. Also, the simulated image can be compared with an idea layout image, the results of which can then be used to reduce the amount of information that is needed to perform the design rule checking.

Claims

1. A method for performing design rule checking for an integrated circuit layout having been subjected to optical proximity correction OPC so that the integrated circuit layout includes OPC features, comprising:

taking said integrated circuit layout including OPC features;

generating a simulation of an exposure made using said integrated circuit layout;

using said simulation to construct a second layout data; and

performing design rule checking of said second layout data.

2. The method of claim 1, wherein said using said simulation includes tracing a contour of features in said simulation to produce said second layout data.

3. The method of claim 1, wherein said second layout data comprises a GDS-II layout data.

4. The method of claim 1, wherein said OPC features include at least one serif.

5. The method of claim 1, wherein said using said second layout data comprises a machine-readable polygon representation of an intensity contour in an image of said simulation.

6. A method for producing an integrated circuit layout, comprising:

subjecting a layout to optical proximity correction OPC to produce an integrated circuit layout including OPC features;

generating a simulation of an exposure made using said integrated circuit layout;

using said simulation to construct a second layout data;

performing design rule checking of said second layout data; and

correcting said integrated circuit layout based upon results of said design rule checking.

7. The method of claim 6, wherein said using said simulation tracing a contour of features in said simulation to produce said second layout data.

8. The method of claim 6, wherein said second layout data comprises a GDS-II layout data.

9. The method of claim 6, wherein said OPC features include at least one serif.

10. The method of claim 6, wherein said using said second layout data comprises a machine-readable polygon representation of an intensity contour in an image of said simulation.

11. The method of claim 6, wherein said generating, using and correcting are performed iteratively until the corrected layout is within predetermined tolerance.