US5308991A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for making a predistorted reticle to compensate for lens distortions
Assignee: National Semiconductor Corp
•
Filing: 1992-06-02
•
Granted: 1994-05-03
•
Expires: 2012-06-02
Abstract
Abstract A method and apparatus for making predistorted masks or reticles which compensate for lens field errors for use in the fabrication of integrated circuit devices. The lens error is first expressed as distortion data. The data is used to produce correction terms which are applied to an interferometrically controlled stage which positions the mask or reticle beneath a writing tool. When the predistorted mask or reticle is used in conjunction with the lens for which the distortion data was obtained, an integrated circuit device is produced which does not incorporate the lens field errors.
Inventors
- 👤 Shay Kaplan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:25
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/68; G03F1/70; B; B82; B82Y; B82Y10/00; B82Y40/00; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/70483; G03F7/70591; G03F7/706; H; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045; H01J37/317; H01J37/3174
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
163 words
A method for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the mask or reticle is produced by controlling the movement of a movable stage containing the mask or reticle, where the stage is disposed beneath a writing tool which writes pattern data to form the mask or reticle, the method comprising: expressing a lens error in terms of lens distortion data; converting the lens distortion data into correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and using the correction terms to control the positioning of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 2
Independent Claim
163 words
A method for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the mask or reticle is produced by controlling the movement of a movable stage containing the mask or reticle, where the stage is disposed beneath a writing tool which writes pattern data to form the mask or reticle, the method comprising: expressing a lens error in terms of lens distortion data; converting the lens distortion data into correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and using the correction terms to control the positioning of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein the lens distortion data is expressed as the image displacement caused by the lens as a function of a radial coordinate on the lens surface.
Claim 4
Dependent Claim
32 words
The method of claim 1 wherein the lens distortion data is expressed as the image displacement caused by the lens as a function of x any y coordinates on the lens surface.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the correction terms are expressed as functions of the x and y coordinates of positions on the lens surface.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein the stage positioning is controlled by a laser interferometer.
Claim 7
Dependent Claim
34 words
The method of claim 5 wherein the laser interferometer has a port for input of a wavelength correction factor, and further wherein the correction terms are input into the interferometer's wavelength correction factor port.
Claim 8
Dependent Claim
20 words
The method of claim 6 wherein the interferometer's wavelength correction factor port is a port for input of environmental data.
Claim 9
Dependent Claim
41 words
The method of claim 5 wherein the interferometrically controlled stage uses a compensation value to correct the wavelength of the laser, and further, wherein the correction terms are used to control the positioning of the stage by adjusting the compensation value.
Claim 10
Independent Claim
195 words
A method for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the mask or reticle is produced by controlling the movement of a movable stage containing the mask or reticle, where the stage is disposed beneath a writing tool which writes pattern data to form the mask or reticle, the method comprising: expressing a lens error in terms of lens distortion data; expressing the lens distortion data as a lens error function, wherein the lens error function is a function of either the radial or x and y coordinates on the lens surface; using the lens error function to generate correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and using the correction terms to control the positioning of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 11
Independent Claim
195 words
A method for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the mask or reticle is produced by controlling the movement of a movable stage containing the mask or reticle, where the stage is disposed beneath a writing tool which writes pattern data to form the mask or reticle, the method comprising: expressing a lens error in terms of lens distortion data; expressing the lens distortion data as a lens error function, wherein the lens error function is a function of either the radial or x and y coordinates on the lens surface; using the lens error function to generate correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and using the correction terms to control the positioning of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 12
Dependent Claim
163 words
Apparatus for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the apparatus includes a writing tool which writes pattern data to form the mask or reticle and a movable stage containing the mask or reticle which is disposed beneath the writing tool, the lens error being expressed in terms of lens distortion data, the apparatus comprising: conversion means for converting the lens distortion data into correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and control means responsive to the correction terms for controlling the position of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 13
Dependent Claim
163 words
Apparatus for producing predistorted masks or reticles which correct for lens field errors for use in the fabrication of integrated circuit devices, wherein the apparatus includes a writing tool which writes pattern data to form the mask or reticle and a movable stage containing the mask or reticle which is disposed beneath the writing tool, the lens error being expressed in terms of lens distortion data, the apparatus comprising: conversion means for converting the lens distortion data into correction terms, wherein the correction terms are a function of the location on the lens through which radiation passes; and control means responsive to the correction terms for controlling the position of the stage, thereby causing the stage to move so that when the writing tool writes pattern data which has not been corrected for the lens error, there is produced a mask or reticle which compensates for the lens error when it is used in conjunction with the lens to fabricate a semiconductor device.
Claim 14
Dependent Claim
31 words
The apparatus of claim 10 wherein the lens distortion data is expressed as the image displacement caused by the lens as a function of a radial coordinate on the lens surface.
Claim 15
Dependent Claim
32 words
The apparatus of claim 10 wherein the lens distortion data is expressed as the image displacement caused by the lens as a function of x and y coordinates on the lens surface.
Claim 16
Dependent Claim
25 words
The apparatus of claim 10 wherein the correction terms are expressed as functions of the x any y coordinates of positions on the lens surface.
Claim 17
Dependent Claim
15 words
The apparatus of claim 10 wherein the stage positioning is controlled by a laser interferometer.
Claim 18
Dependent Claim
34 words
The apparatus of claim 14 wherein the laser interferometer has a port for input of a wavelength correction factor, and further wherein the correction terms are input into the interferometer's wavelength correction factor port.
Claim 19
Dependent Claim
20 words
The apparatus of claim 15 wherein the interferometer's wavelength correction factor port is a port for input of environmental data.
Claim 20
Dependent Claim
41 words
The apparatus of claim 14 wherein the interferometrically controlled stage uses a compensation value to correct the wavelength of the laser, and further, wherein the correction terms are used to control the position of the stage by adjusting the compensation value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-05-02 | 1997-11-01 | 1998-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-02 | 2001-11-01 | 2002-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-02 | 2005-11-01 | 2006-05-03 | $7700.00 | Window Closed / Lapsed |