Patent US5689209A successfully refreshed from Google Patents.
Patent US6120953A successfully refreshed from Google Patents.
US6120953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of optical proximity correction
Assignee: United Microelectronics Corp
•
Filing: 1999-04-23
•
Granted: 2000-09-19
•
Expires: 2019-04-23
Abstract
Abstract A method of optical proximity correction. A main pattern is provided. The main pattern has a critical dimension. When the critical dimension is reduced to reach a first reference value or below, a serif/hammerhead is added onto the main pattern. When the critical dimension is further reduced to a second reference value or below, an assist feature is added onto the main pattern. The corrected pattern is then transferred to a layer on wafer with an improved fidelity.
Inventors
- 👤 Chin-Lung Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:14
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/70441; G03F1/00; G03F1/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
67 words
A method of optical proximity correction, comprising: providing a main pattern; checking a critical dimension of the main pattern; adding a serif or a hammerhead on the main pattern when the critical dimension is no larger than 2.5 times of a wavelength of a light source for exposure; and adding an assist feature on the main pattern when the critical dimension is no larger than the wavelength.
Claim 2
Independent Claim
67 words
A method of optical proximity correction, comprising: providing a main pattern; checking a critical dimension of the main pattern; adding a serif or a hammerhead on the main pattern when the critical dimension is no larger than 2.5 times of a wavelength of a light source for exposure; and adding an assist feature on the main pattern when the critical dimension is no larger than the wavelength.
Claim 3
Dependent Claim
19 words
The method according to claim 1, wherein the assist feature is added after adding the serif or the hammerhead.
Claim 4
Dependent Claim
21 words
The method according to claim 1, comprising further a step of exposure using the light source after adding the assist feature.
Claim 5
Independent Claim
97 words
A method of optical proximity correction, comprising: providing a main pattern; checking a critical dimension of the main pattern; adding a first correction pattern to the main pattern when the critical dimension is less than or equal to a first reference value, the first reference value being equal to 2.5 times a wavelength of a light source for exposure; adding a second correction pattern to the main pattern when the critical dimension is less than or equal to a second reference value, the second reference value being equal to a wavelength of a light source for exposure.
Claim 6
Independent Claim
97 words
A method of optical proximity correction, comprising: providing a main pattern; checking a critical dimension of the main pattern; adding a first correction pattern to the main pattern when the critical dimension is less than or equal to a first reference value, the first reference value being equal to 2.5 times a wavelength of a light source for exposure; adding a second correction pattern to the main pattern when the critical dimension is less than or equal to a second reference value, the second reference value being equal to a wavelength of a light source for exposure.
Claim 7
Dependent Claim
23 words
The method according to claim 4, wherein the first correction pattern comprises at least a serif on a corner of the main pattern.
Claim 8
Dependent Claim
16 words
The method according to claim 4, wherein the first correction pattern comprises at least a hammerhead.
Claim 9
Dependent Claim
15 words
The method according to claim 4, wherein the second correction pattern comprises an assist feature.
Claim 10
Independent Claim
90 words
A method of optical proximity correction, comprising: providing a main pattern to be transferred via a photolithography process, wherein the main pattern has a critical dimension and a plurality of right-angled corners; adding one serif on each of the right-angled corners when the critical dimension is less than or equal to 2.5 times of a wavelength of a light source used for the photolithography process; and after adding the serifs, adding an assist feature onto the main pattern when the critical dimension is less than or equal to the wavelength.
Claim 11
Independent Claim
90 words
A method of optical proximity correction, comprising: providing a main pattern to be transferred via a photolithography process, wherein the main pattern has a critical dimension and a plurality of right-angled corners; adding one serif on each of the right-angled corners when the critical dimension is less than or equal to 2.5 times of a wavelength of a light source used for the photolithography process; and after adding the serifs, adding an assist feature onto the main pattern when the critical dimension is less than or equal to the wavelength.
References Cited (Backward Citations)
US5879844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-09-19 | 2004-03-20 | 2004-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-09-19 | 2008-03-20 | 2008-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-09-19 | 2012-03-20 | 2012-09-19 | $7700.00 | Window Closed / Lapsed |