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US6049660A Expired / Lapsed US ⏱️ 0.0 years remaining

Simulation method in lithographic process

Assignee: SK Hynix Inc
•
Filing: 1997-12-24
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Granted: 2000-04-11
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Expires: 2017-12-24
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Abstract

Abstract A simulation method for simulating in a lithographic process is disclosed, and the method can expect a size of a resist pattern by obtaining a diffused aerial image model(DAIM) by determining a simplified model in a aerial image to represent a resist process without simulating full processes including a resist process, and then applying the DAIM to a threshold model.

Inventors

  • 👤 Chang Nam Ahn
  • 👤 Hee Bom Kim

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 11:45
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/708; H; H10; H10P; H10P76/00; G03F1/00; G03F1/36; G03F7/20; G03F7/70483; G03F7/70491; G03F7/705

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 84 words
A simulation method in a lithography process, comprising the steps of: obtaining an aerial image by inputting exposure apparatus conditions and a mask layout in a resist process for I-lines; regarding said aerial image the same as an acid distribution being produced from a resist in an exposure process, and obtaining a diffused aerial image in consideration of diffusion of said acid in a post expose bake process; applying said diffused aerial image to a threshold model, thereby modeling an expected resist pattern size.
Claim 2
Dependent Claim 84 words
A simulation method in a lithography process, comprising the steps of: obtaining an aerial image by inputting exposure apparatus conditions and a mask layout in a resist process for I-lines; regarding said aerial image the same as an acid distribution being produced from a resist in an exposure process, and obtaining a diffused aerial image in consideration of diffusion of said acid in a post expose bake process; applying said diffused aerial image to a threshold model, thereby modeling an expected resist pattern size.
Claim 3
Dependent Claim 51 words
The simulation method as defined in claim 1, said aerial image is obtained by the following equation ##EQU14## where I 0 is said aerial image and F, F -1 represent Fourier transformation to ξ, n space, inverse Fourier transformation from ξ, n space, respectively, and σ B is a fitting parameter.
Claim 4
Dependent Claim 37 words
The simulation method as defined in claim 1, wherein said acid distribution is treated as that of two dimensions so that said aerial image is regarded the same as said acid distribution being produced from said resist.
Claim 5
Dependent Claim 40 words
The simulation method as defined in claim 1, wherein a thickness of said resist is determined to be less than 15,000 Å so that said aerial image is regarded the same as said acid distribution being produced from said resist.
Claim 6
Dependent Claim 86 words
A simulation method in a lithography process, comprising the steps of: obtaining an aerial image by inputting exposure apparatus conditions and a mask layout in a resist process for I-lines; regarding said aerial image the same as an acid distribution being produced from a resist in an exposure process, and obtaining a diffused aerial image in consideration of diffusion and amplification of said acid in a post expose bake process; applying said diffused aerial image to a threshold model, thereby modeling an expected resist pattern size.
Claim 7
Dependent Claim 86 words
A simulation method in a lithography process, comprising the steps of: obtaining an aerial image by inputting exposure apparatus conditions and a mask layout in a resist process for I-lines; regarding said aerial image the same as an acid distribution being produced from a resist in an exposure process, and obtaining a diffused aerial image in consideration of diffusion and amplification of said acid in a post expose bake process; applying said diffused aerial image to a threshold model, thereby modeling an expected resist pattern size.
Claim 8
Dependent Claim 51 words
The simulation method as defined in claim 5, said aerial image is obtained by the following equation ##EQU15## where I 0 is said aerial image and F, F -1 represent Fourier transformation to ξ, n space, inverse Fourier transformation from ξ, n space, respectively, and σ B is a fitting parameter.
Claim 9
Dependent Claim 37 words
The simulation method as defined in claim 5, wherein said acid distribution is treated as that of two dimensions so that said aerial image is regarded the same as said acid distribution being produced from said resist.
Claim 10
Dependent Claim 40 words
The simulation method as defined in claim 5, wherein a thickness of said resist is determined to be less than 15,000 Å so that said aerial image is regarded the same as said acid distribution being produced from said resist.

References Cited (Backward Citations)

US5240813A Cited
US5644390A Cited
US5538833A Cited
US5702767A Cited
US5655110A Cited
US5717612A Cited
US5889678A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-04-11 2003-10-11 2004-04-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-04-11 2007-10-11 2008-04-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-04-11 2011-10-11 2012-04-11 $7700.00 Window Closed / Lapsed

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