SIMULATION METHOD AND SIMULATION PROGRAM

• US 20090048813A1
• Filed: 08/15/2008
• Published: 02/19/2009
• Est. Priority Date: 08/16/2007
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ichikawa, Takashi, Takase, Toshiro, Tamaoki, Naoki
• Application Number:
  US12/192,197
• Publication Number:
  US 20090048813A1
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: G06F 30/23 using finite element methods [FEM] or finite difference methods [FDM]

Abstract

A simulation method is configured to simulate a feature profile of a material surface. The simulation method includes using an algorithm of repeating a step of calculating a surface growth rate and a step of skipping the calculation of the surface growth rate. The surface growth rate is calculated in the step of skipping the calculation of the algorithm if the material surface traverses a material interface.

Claims

1. A simulation method configured to simulate a feature profile of a material surface, the simulation method comprising:

using an algorithm of repeating a step of calculating a surface growth rate and a step of skipping the calculation of the surface growth rate,

the surface growth rate being calculated in the step of skipping the calculation of the algorithm if the material surface traverses a material interface.

2. The method according to claim 1, wherein, in a step in which the material surface does not traverse the material interface, the calculation of the surface growth rate is skipped, and the feature profile is time-evolved.

3. The method according to claim 1, wherein the calculation of the surface growth rate is completed when a predetermined processing time has elapsed.

4. The method according to claim 1, wherein the calculation of the surface growth rate is completed when the material surface reaches a predetermined target point.

5. The method according to claim 1, wherein a time interval Δ

t of the steps is determined by using a distance from the material surface to the material interface and a surface growth rate.

6. The method according to claim 5, wherein the distance is a level set function at the material interface.

7. The method according to claim 1, wherein the material is etched and the surface growth rate is negative.

8. The method according to claim 1, wherein a time interval Δ

t of the steps is determined by using a level set function and a surface growth rate.

9. The method according to claim 8, wherein the level set function is a difference between the value of the level set function on a mesh in a computational region where the value is saved and the value of the level set function at the material interface nearest to the mesh.

10. The method according to claim 1, wherein the step in which the material surface traverses the material interface,

the calculating includes:

calculating a first surface growth rate before the traversal of the material interface and a second surface growth rate after the traversal of the material interface; and

using the first and second surface growth rate to calculate a new surface growth rate in the step.

11. The method according to claim 1, wherein the step in which the material surface traverses the material interface,

the calculating includes:

calculating profile evolution factors of two or more materials adjacent to the material interface; and

using the profile evolution factors to calculate a new profile evolution factor in the step.

12. A simulation program configured to cause a computer to simulate a feature profile of a material surface, the program causing the computer to perform:

using an algorithm of repeating a step of calculating a surface growth rate and a step of skipping the calculation of the surface growth rate,

the surface growth rate being calculated in the step of skipping the calculation of the algorithm if the material surface traverses a material interface.

13. The program according to claim 12, wherein, in a step in which the material surface does not traverse the material interface, the calculation of the surface growth rate is skipped, and the feature profile is time-evolved.

14. The program according to claim 12, wherein the calculation of the surface growth rate is completed when a predetermined processing time has elapsed.

15. The program according to claim 12, wherein the calculation of the surface growth rate is completed when the material surface reaches a predetermined target point.

16. The program according to claim 12, wherein a time interval Δ

t of the steps is determined by using a distance from the material surface to the material interface and a surface growth rate.

17. The program according to claim 16, wherein the distance is a level set function at the material interface.

18. The program according to claim 12, wherein a time interval Δ

t of the steps is determined by using a level set function and a surface growth rate.

19. The program according to claim 12, wherein in the step in which the material surface traverses the material interface,

the calculating includes:

calculating a first surface growth rate before the traversal of the material interface and a second surface growth rate after the traversal of the material interface; and

using the first and second surface growth rate to calculate a new surface growth rate in the step.

20. The program according to claim 12, wherein in the step in which the material surface traverses the material interface,

the calculating includes:

calculating profile evolution factors of two or more materials adjacent to the material interface; and

using the profile evolution factors to calculate a new profile evolution factor in the step.